Program and Abstract Book - SRON

ISSTT 2008 

19 th International Symposium on Space Terahertz Technology 

19 th International Symposium on 

Space Terahertz Technology 

April 28-30, 2008 

Groningen, The Netherlands 

Program 

and 

Abstract 

Book 

Edited by: 

Wolfgang Wild 

Website: 

www.sron.nl/isstt2008 

E-mail: 

isstt2008@sron.nl 

Foto: HIFI FM under inspection 

Netherlands Institute for Space Research 

Netherlands Organisation for Scientific


Groningen 

City Center 

Bus departure for 

conference dinner 

Tuesday 29 April 6pm 

Hotel de Ville 

Symposium Venue 

Academy Building 

University of Groningen 

Registration & Reception 

Sunday 27 April 08, 5-8 pm 

Café Mr. Mofongo 

NH Hotel Hanzeplein 

Eden City Hotel 

1000 ft 

200 m 

University 

Guesthouse 

Train station 

Hotel 

Schimmelpenninkhuys


CONTENTS 

SPONSORS 2 

WELCOME 3 

INFORMATION 4 

PROGRAM AT A GLANCE 7 

DETAILED SYMPOSIUM PROGRAM 8 

SESSION 1 – TERAHERTZ SYSTEMS 15 

SESSION 2 – HEB MIXERS 21 

SESSION 3 – SIS MIXERS 29 

SESSION 4 – HERSCHEL-HIFI 37 

SESSION 5 – DIRECT DETECTORS 45 

SESSION 6 – THZ RECEIVERS / BACKENDS 1 53 

SESSION 7 – LOCAL OSCILLATORS 61 

SESSION 8 – SCHOTTKY MIXERS 67 

SESSION 9 – ALMA 73 

SESSION 10 – THZ RECEIVERS / BACKENDS 2 81 

SESSION 11 – NOVEL DEVICES & MEASUREMENTS 91 

SESSION 12 – OPTICS & COMPONENTS 97 

POSTER PRESENTATIONS 105 

POSTER ABSTRACTS 109 

REGISTERED PARTICIPANTS 165 

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SPONSORS 

We want to thank SRON, the Kapteyn Astronomical Institute of the University of 

Groningen, NOVA Netherlands Research School for Astronomy, and the Royal 

Netherlands Academy of Arts and Sciences whose contributions helped to make the 

19 th International Symposium on Space Terahertz Technology, ISSTT2008, possible. 

2


WELCOME 

SRON Netherlands Institute for Space Research, the University of Groningen, and 

TU Delft welcome you to the 19 th International Symposium on Space Terahertz 

Technology, ISSTT2008, held from April 28 to 30, 2008, in Groningen, the 

Netherlands. 

A total of 118 abstracts was accepted. 63 abstracts are scheduled for oral 

presentation and 55 for poster presentation. There are 10 invited contributions. We 

would like to thank the Scientific Organizing Committee for the abstract review. 

Scientific Organizing Committee 

Victor Belitsky (Chalmers University of Technology, Sweden) 

Ray Blundell (Harvard-Smithsonian Center for Astrophysics, USA) 

Tom Crowe (VDI / University of Virginia, USA) 

Thijs de Graauw (SRON / Leiden Observatory, the Netherlands) 

Brian Ellison (Rutherford Appleton Laboratory, UK) 

J.R. Gao (SRON / TU Delft, the Netherlands) 

Gregory Goltsman (Moscow State Pedagogical University, Russia) 

Karl Jacobs, (KOSMA, Germany) 

Tony Kerr (NRAO, USA) 

Teun Klapwijk (TU Delft, the Netherlands) 

Alain Maestrini (Paris University, France) 

Imran Mehdi (JPL, USA) 

Tom Phillips (Caltech, USA) 

Albrecht Poglitsch (MPE, Germany) 

Antti Räisänen (Helsinki University of Technology, Finland) 

Yutaro Sekimoto (NAOJ, Japan) 

Sheng-Cai Shi (Purple Mountain Observatory, China) 

Peter Siegel (JPL, USA) 

Jan Stake (Chalmers University of Technology, Sweden) 

Wolfgang Wild, chair (SRON / University of Groningen, the Netherlands) 

Jonas Zmuidzinas (Caltech, USA) 

We would like to thank the sponsors (see opposite page) whose contributions made 

the ISSTT2008 possible. The local arrangement were done by the Local Organizing 

Committee at SRON and the University of Groningen. 

Local Organizing Committee 

Wolfgang Wild (chair), Hennie Zondervan, Joost Adema, Petra Huizinga, Nico 

Sijm, Hans Bloemen, and Jasper Wamsteker 

The Symposium Organizers 

Wolfgang Wild 

Thijs de Graauw 

Teun Klapwijk 

Jian-Rong Gao 

SRON / University of Groningen 

Leiden Observatory 

Delft University of Technology 

SRON / Delft University of Technology 

3


Registration 

INFORMATION 

On Sunday, 27 April, from 17:00 to 20:00, a registration reception will be held at Café 

Mr. Mofongo (about 50m to the right of the conference venue main entrance, see 

map). Registration is also possible starting at 8:00 on each symposium day in the 

entrance hall of the University main building (see below). 

Symposium Venue 

The symposium is held in the main building of the University of Groningen (the 

"Academiegebouw" or “Academy building”), Broerstraat 5, 9712 CP Groningen, at the 

“Geertsemaazaal” lecture hall, 3rd floor. The Academy building is in the very city 

center and within walking distance of the city center hotels. It was built in 1909 in the 

Northern Netherlands Renaissance style on the same terrain where in 1614 the 

University’s first Academy building was erected. 

The Academy building of the University of Groningen 

where the ISSTT2008 symposium is held. 

Oral presentations 

All oral presentation will be held in the Geertsemazaal, Academy building, University 

of Groningen, Broerstraat 5, 3 rd floor. Invited talks are allocated 20 min plus 5 min for 

questions, contributed talks are allocated 12 min plus 3 min for questions. 

Presentations must be horizontal in .ppt (much preferred) or .pdf format. Please 

embed the fonts when saving the file to avoid formatting problems. 

Please upload your presentation not later than 25 April. (Speakers receive separate 

instructions via email). The conference hall has 266 seats - please do not choose the 

font size too small. A beamer and a Windows PC (with MS Powerpoint and Adobe 

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Acrobat) are available. Please contact the chairperson of your session before the 

session begins to confirm your presence. 

Poster presentations 

The poster session and lunch breaks will be held in the Bruynzaal and Spiegelzaal 

on the ground floor next to the main entrance of the Academy building. 

Poster board size is 1 m (width) x 2 m (height). We recommend posters using A0 (or 

similar) paper size (~ 0,84 m x 1,2 m). Posters can be set up starting Monday 28 

April 10:00 and can remain on display until Wednesday 30 April 17:00. 

A poster session and reception will be held on Monday 28 April 18:00. The reception 

is offered jointly by the Province of Groningen, the City of Groningen and the 

University of Groningen. 

Paper submission for the Proceedings 

Proceedings containing the conference papers will be published. Deadline for 

electronic paper submission is 1 June 2008. Each paper can have max. 10 pages. 

Instructions for paper submission will be made available at the symposium and on 

the symposium web site. 

Lunch, poster reception, symposium dinner 

Lunch on the three conference days is included in the registration fee and will be 

served next to the poster area in the Bruynzaal and Spiegelzaal on the ground floor 

(close to the main entrance of the Academy building). 

On Monday, 28 April 18:00, a poster session will be held and a reception will be 

offered by the Province of Groningen, the City of Groningen, and the University of 

Groningen. Conference greetings will be given by Prof. Frans Zwarts, Rector 

Magnificus, University of Groningen, and Prof. Karel Wakker, Director SRON. 

On Tuesday, 29 April, the symposium dinner will take place in a small village outside 

Groningen. Bus transport will be provided leaving from the central square (Grote 

Markt) at 18:00 (see map). 

Registered participants 

A list of registered participants is given at the end of this book. 

Visit to SRON Groningen labs 

On Thursday, 1 May, a visit to the SRON laboratories in Groningen will be organized. 

Please contact W. Wild if you are interested. 

5


6


19 th International Symposium on Space 

Terahertz Technology – ISSTT 2008 

28 – 30 April 2008, Groningen, the Netherlands 

Organized by SRON, TU Delft and University of Groningen 

Program at a glance 

Sunday 27 April 

17:00 – 20:00 Registration and drinks, Café Mr. Mofongo 

Thursday 01 May (optional) 10:00 – 12:00 SRON lab tour (Contact: W. Wild) 

Monday 28 April Tuesday 29 April Wednesday 30 April 

08:00 Registration 08:00 Registration 08:00 Registration 

08:30 Symposium opening 

08:40 – 09:55 Session 1 – 

THz Systems 

Chair: Ray Blundell 

08:30 – 10:15 Session 5 – 

Direct Detectors 

Chair: Jian-Rong Gao 

08:30 – 10:25 Session 9 – 

ALMA 

Chair: Wolfgang Wild 

09:55 – 10:20 Coffee 10:15 – 10:40 Coffee 10:25 – 10:50 Coffee 

10:20 – 11:10 

Session 1 continued – 

THz Systems (cont’d) 

10:40 – 12:35 Session 6 – 

THz Receivers/Backends 1 

Chair: Jacob Kooi 

10:50 – 12:50 Session 10 – 

THz Receivers/Backends 2 

Chair: Victor Belitsky 

11:10 – 12:40 Session 2 – 

HEB Mixers 

Chair: Teun Klapwijk 

12:40 – 14:00 Lunch 12:35 – 13:45 Lunch 12:50 – 14:05 Lunch 

14:00 – 15:45 Session 3 – 

SIS Mixers 

Chair: Sheng-Cai Shi 

13:45 – 15:20 Session 7 – 

Local Oscillators 

Chair: Neal Erickson 

14:05 – 15:05 Session 11 – 

Novel devices & 

Measurements 

Chair: Paul Richards 

15:45 – 16:10 Coffee 15:20 – 15:45 Coffee 15:05 – 15:30 Coffee 

16:10 – 17:50 Session 4 – 

Herschel-HIFI 

Chair: Thijs de Graauw 

18:00 – 19:00 

Poster Session and 

Reception 

15:45 – 17:00 Session 8 – 

Schottky Mixers 

Chair: Imran Mehdi 

18:00 Bus departure to dinner 

18:30 Conference dinner 

Invited speaker: Prof. J. Tucker 

22:30 Bus departure to 

Groningen 

15:30 – 17:00 Session 12 – 

Optics and Components 

Chair: Edward Tong 

17:00 Adjourn 

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DETAILED SYMPOSIUM PROGRAM 

Monday 28 April 2008 

08:00 Registration 

08:30 - 08:40 Welcome and announcements 

Wolfgang Wild, SRON / 


08:40 - 11:10 Session 1 - Terahertz Systems Chair: Ray Blundell 

08:40 - 09:05 1-1 SPICA and its instrumentation (Invited) Takao Nakagawa, 

ISAS/JAXA 

09:05 - 09:30 1-2 Stratospheric Observatory for Infrared Astronomy 

(Invited) 

09:30 - 09:55 1-3 The Stratospheric TeraHertz Observatory (STO) 

(Invited) 

Eric Becklin, UCLA 

Chris Walker, University of 

Arizona 

09:55 - 10:20 Coffee 

10:20 - 10:45 1-4 New ground-based facilities for THz astronomy 

(Invited) 

10:45 - 11:10 1-5 CMB experiments at mm and submm wavelengths 

(Invited) 

Gordon Stacey, Cornell 

University 

Paul Richards, University 

of California, Berkeley 

11:10 - 12:40 Session 2 - HEB Mixers Chair: Teun Klapwijk 

11:10 - 11:25 2-1 Terahertz heterodyne array based on NbN HEB 

mixers 

Sergey Cherednichenko, 

Chalmers University of 

Technology 

11:25 - 11:40 2-2 NbZr films for THz phonon-cooled HEB mixers Andrey Smirnov, Moscow 

State Pedagogical 

University 

11:40 - 11:55 2-3 Sensitivity of a heterodyne receiver at 4.3 THz 

based on a NbN hot electron bolometer mixer 

Pourya Khosrohpanah, 

SRON 

11:55 - 12:10 2-4 Demonstration of a heterodyne receiver for 

detection of OH line at 3.5 THz based on a 

superconducting HEB mixer and a distributed 

feedback quantum cascade laser 

12:10 - 12:25 2-5 Temperature Dependence of HEB Mixer 

Performance 

Wen Zhang, Purple 

Mountain Observatory / 


Shoichi Shiba, University of 

Tokyo 

12:25 - 12:40 2-6 Fabrication and characterization of NbN HEB mixers 

with in situ gold contacts 

Gregory Goltsman, 

Moscow State Pedagogical 

University 

12:40 - 14:00 Lunch 

8



14:00 - 15:45 Session 3 - SIS Mixers Chair: Sheng-Cai Shi 

14:00 - 14:15 3-1 Low noise 1.4 THz SIS mixer for SOFIA Alexandre Karpov, Caltech 

14:15 - 14:30 3-2 Development of an All-NbN Waveguide SIS Mixer 

for 0.5 THz 

Jing Li, Purple Mountain 

Observatory 

14:30 - 14:45 3-3 A novel THz SIS mixer with a NbTiN-groundplane Akira Endo, NAOJ / 

University of Tokyo 

14:45 - 15:00 3-4 Design and Performance of Waveguide Mixers with 

All NbN tunnel junctions on MgO substrates 

15:00 - 15:15 3-5 Bandwidth of Nb/AlN/Nb SIS mixers suitable for 

frequencies around 700 GHz 

15:15 - 15:30 3-6 RF Performance of a 600 - 720 GHz Sideband- 

Separating Mixer with All-Copper Micromachined 

Waveguide Mixer Block 

15:30 - 15:45 3-7 100 GHz sideband separating mixer with wide IF 

band: First results 

15:45 - 16:10 Coffee 

Wenlei Shan, Purple 

Mountain Observatory 

Chris Lodewijk, Delft 

University of Technology 

Patricio Mena, SRON / 


Doris Maier, IRAM 

16:10 - 17:50 Session 4 - Herschel-HIFI Chair: Thijs de Graauw 

16:10 - 16:35 4-1 The Herschel Mission and Key Programmes 

(Invited) 

16:35 - 16:50 4-2 Performance of the superconducting mixers for the 

HIFI instrument 

16:50 - 17:05 4-3 HIFI Flight Model Testing at Instrument and Satellite 

Level 

Göran Pilbratt, ESA 

Gert de Lange, SRON 

Pieter Dieleman, SRON 

17:05 - 17:20 4-4 HIFI Instrument Stability as measured during the ILT 

phase: Results and operational impacts 

Jacob Kooi, Caltech 

17:20 - 17:35 4-5 Flight Attenuators for the HIFI Local Oscillator 

Bands 

Willem Jellema, SRON 

17:35 - 17:50 4-6 HIFI Pre-launch Calibration Results David Teyssier, ESA 

18:00 - 19:00 Poster Session and Reception 

Conference greetings by 

Prof. Frans Zwarts, Rector Magnificus, University of Groningen, and 

Prof. Karel Wakker, Director SRON 

The reception is offered jointly by the Province of Groningen, the City of 

Groningen, and the University of Groningen 

9


Tuesday 29 April 2008 


08:30 - 10:15 Session 5 - Direct Detectors Chair: Jian-Rong Gao 

08:30 - 08:45 5-1 Lumped Element Kinetic Inductance Detectors for 

Far Infrared Astronomy 

08:45 - 09:00 5-2 Antenna coupled Kinetic Inductance Detectors for 

space based sub-mm astronomy 

09:00 - 09:15 5-3 Antenna-coupled Microwave Kinetic Inductance 

detectors (MKIDs) for mm and submm imaging 

arrays 

09:15 - 09:30 5-4 Contribution of dielectrics to frequency and noise of 

NbTiN superconducting resonators 

Simon Doyle, Cardiff 

University 

Stephen Yates, SRON 

Anastasios Vayonakis, 

Caltech 

Rami Barends, Delft 


09:30 - 09:45 5-5 Microstrip-coupled TES bolometers for CLOVER Damian Audley, University 

of Cambridge 

09:45 - 10:00 5-6 Superconducting transition detectors as thermal 

power amplifiers for cryomultiplexing 

10:00 - 10:15 5-7 A Parallel/Series Array of Superconducting Cold- 

Electron Bolometers with SIS Tunnel Junctions 

Panu Helistö, VTT 

Leonid Kuzmin, Chalmers 


10:15 - 10:40 Coffee 

10:40 - 12:35 Session 6 - THz Receivers / Backends 1 Chair: Jacob Kooi 

10:40 - 11:05 6-1 Innovative technologies for THz heterodyne 

detection (Invited) 

11:05 - 11:20 6-2 2.5-THz heterodyne receiver with quantum cascade 

laser and hot electron bolometer mixer in a pulse 

tube cooler 

11:20 - 11:35 6-3 CHAMP+: A powerful sub-millimeter heterodyne 

array 

11:35 - 11:50 6-4 Large Format Heterodyne Arrays for Terahertz 

Astronomy 

11:50 - 12:05 6-5 APEX Band T2 1.25 – 1.39 THz Waveguide 

Balanced HEB Receiver 

12:05 - 12:20 6-6 Instrumentation for Millimetron - a large space 

antenna for THz astronomy 

12:20 - 12:35 6-7 The Next Generation of Fast Fourier Transform 

Spectrometer 

Tom Phillips, Caltech 

Heiko Richter, German 

Aerospace Center 

Stefan Heyminck, Max- 

Planck-Institut für 

Radioastronomie 

Christopher Groppi, 

University of Arizona 

Denis Meledin, Chalmers 


Wolfgang Wild, SRON 

Bernd Klein, Max-Planck- 

Institut for Radioastronomy 

10



12:35 - 13:45 Lunch 

13:45 - 15:20 Session 7 - Local Oscillators Chair: Neal Erickson 

13:45 - 14:10 7-1 Pushing the limits of multiplier chain local oscillators 

(Invited) 

Imran Mehdi, JPL 

14:10 - 14:35 7-2 Experiences with QCL local oscillators (Invited) Heinz-Wilhelm Hübers, 

German Aerospace Center 

14:35 - 14:50 7-3 High angular resolution far-field beam pattern of a 

surface-plasmon THz quantum cascade laser 

14:50 - 15:05 7-4 Integration of Terahertz Quantum Cascade Lasers 

with Lithographically Micromachined Rectangular 

Waveguides 

15:05 - 15:20 7-5 Phase-locked Local Oscillator for Superconducting 

Integrated Receiver 

Jian-Rong Gao, SRON / 

TU Delft 

Michael Wanke, Sandia 

National Labs 

Valery Koshelets, Inst. of 

Radio Engineering and 

Electronics 

15:20 - 15:45 Coffee 

15:45 - 17:00 Session 8 - Schottky Mixers Chair: Imran Mehdi 

15:45 - 16:00 8-1 A Schottky-Diode Balanced Mixer for 1.5 THz Neal Erickson, University 

of Massachusetts 

16:00 - 16:15 8-2 Development and Characterization of THz Planar 

Schottky Diode Mixers and Detectors 

16:15 - 16:30 8-3 State-of-the-Art Quasi-Vertical Schottky Diodes for 

THz-Applications 

16:30 - 16:45 8-4 Schottky Diode Mixers on Gallium Arsenide 

Antimonide? 

16:45 - 17:00 8-5 Development of a 340 GHz Sub-Harmonic Image 

Rejection Mixer Using Planar Schottky Diodes 

Jeffrey Hesler, VDI / UVA 

Oleg Cojocari, ACST 

GmbH 

Erich Schlecht, JPL 

Bertrand Thomas, 

Rutherford Appleton 

Laboratory 

18:00 Bus departure from Groningen 

18:30 - 22:30 Conference Dinner at Melkema in Huizinge 

Invited speaker: Prof. John Tucker - "From Super-Schottky to SIS Mixing" 

22:30 Bus departure from Melkema 

11


Wednesday 30 April 2008 


08:30 - 10:25 Session 9 - ALMA Chair: Wolfgang Wild 

08:30 - 08:55 9-1 Submillimeter Interferometers: New standards for 

future instrumentation (Invited) 

Richard Hills, ALMA-JAO 

08:55 - 09:10 9-2 The ALMA Front Ends: an overview Gie Han Tan, ESO 

09:10 - 09:25 9-3 Design and Development of ALMA Band 4 Cartridge 

Receiver 

Shin'ichiro Asayama, 

NAOJ 

09:25 - 09:40 9-4 ALMA Band 5 (163-211 GHz) Sideband Separating 

Mixer Design 

Bhushan Billade, Chalmers 


09:40 - 09:55 9-5 Development of ALMA Band 8 (385-500 GHz) 

Cartridge and its Measurement System 

Yutaro Sekimoto, NAOJ 

09:55 - 10:10 9-6 ALMA Band 9 cartridge Andrey Baryshev, SRON / 


10:10 - 10:25 9-7 Measurement of Emissivity of the ALMA Antenna 

Panel at 840 GHz Using NbN-Based Heterodyne 

SIS Receiver 

Sergey Shitov, NAOJ / 

IREE 

10:25 - 10:50 Coffee 

10:50 - 12:50 Session 10 - THz Receivers / Backends 2 Chair: Victor Belitsky 

10:50 - 11:05 10-1 Spectrometers for (sub)mm radiometer applications Anders Emrich, Omnisys 

11:05 - 11:20 10-2 Flight configuration of the TELIS instrument Pavel Yagoubov, SRON 

11:20 - 11:35 10-3 Performance Characterization of GISMO, a 2 Johannes Staguhn, 

Millimeter TES Bolometer Camera used at the IRAM NASA/GSFC & University 

30 m Telescope 

of Maryland 

11:35 - 11:50 10-4 350GHz band Sideband Separating Receiver for 

ASTE 

Hirofumi Inoue, University 

of Tokyo 

11:50 - 12:05 10-5 Development of a Waveguide-Type Dualpolarization 

Sideband-Separating SIS Receiver 

System in 100 GHz Band for the NRO 45-m Radio 

Telescope 

12:05 - 12:20 10-6 A modular 16-pixel terahertz imager system 

applying superconducting microbolometers and 

room temperature read-out electronics 

Taku Nakajima, Osaka 

Prefecture University 

Mikko Leivo, VTT 

12



12:20 - 12:35 10-7 A novel heterodyne interferometer for millimetre and 

submillimetre astronomy 

Paul Grimes, Oxford 

University 

12:35 - 12:50 10-8 A 600 GHz Imaging Radar for Contraband Detection Goutam Chattopadhyay, 

JPL/Caltech 

12:50 - 14:05 Lunch 

14:05 - 15:05 Session11 - Novel Devices & Measurements Chair: Paul Richards 

14:05 - 14:20 11-1 Experimental detection of terahertz radiation in 

bundles of single wall carbon nanotubes 

Sigfrid Yngvesson, 

University of 

Massachusetts 

14:20 - 14:35 11-2 An Empirical probe to the Operation of SIS Edward Tong, Harvard- 

Receivers -- Revisiting the Technique of Intersecting Smithsonian Center for 

Lines 

Astrophysics 

14:35 - 14:50 11-3 Short GaAs/AlAs superlattices as THz radiation 

sources 

Dmitry Paveliev, Nizhny 

Novgorod State University 

14:50 - 15:05 11-4 A new experimental procedure for determining the 

response of bolometric detectors to fields in any 

Christopher Thomas, 

University of Cambridge 

15:05 - 15:30 Coffee 

15:30 - 17:00 Session 12 - Optics & Components Chair: Edward Tong 

15:30 - 15:45 12-1 Silicon Micromachined Components at Terahertz 

Frequencies for Astrophysics and Planetary 

Applications 

15:45 - 16:00 12-2 Microfabrication Technology for All-Metal Sub-mm 

and THz Waveguide Receiver Components 

16:00 - 16:15 12-3 The fabrication and testing of novel smooth-walled 

feed horns for focal plane arrays 

16:15 - 16:30 12-4 Optics Design and Verification for the APEX Single- 

Pixel Heterodyne Facility Instrument 

16:30 - 16:45 12-5 Backward Couplers Waveguide Orthomode 

Transducer for 84-116 GHz 

16:45 - 17:00 12-6 Physical Optics Analysis of the ALMA Band 5 Front 

End Optics 

Goutam Chattopadhyay, 

JPL/Caltech 

Vincent Desmaris, 


Technology 

Phichet Kittara, Mahidol 

University 

Olle Nyström, Chalmers 


Alessandro Navarrini, INAF- 

Cagliari Astronomy 

Observatory 

Mark Whale, NUI 

Maynooth 

17:00 Adjourn 

13


14


Session 1 – Terahertz Systems 


08:40 – 11:10 

Chair: Ray Blundell 

08:40 - 09:05 1-1 SPICA and its instrumentation (Invited) Takao Nakagawa, 

ISAS/JAXA 

09:05 - 09:30 1-2 Stratospheric Observatory for Infrared Eric Becklin, 

Astronomy (Invited) 

UCLA 

09:30 - 09:55 1-3 The Stratospheric TeraHertz Observatory Chris Walker, 

(STO) (Invited) 

Univ of Arizona 

09:55 - 10:20 Coffee 

10:20 – 10:45 1-4 New ground-based facilities for THz Gordon Stacey, 

astronomy (Invited) 

Cornell University 

10:45 - 11:10 1-5 CMB experiments at mm and submm Paul Richards, 

wavelengths (Invited) 

Univ of California, 

Berkeley 

15


Invited presentation 1-1 

SPICA and its Instrumentation 

Takao Nakagawa, ISAS/JAXA (Japan) 

We present an overview and the current status of SPICA (Space Infrared Telescope 

for Cosmology and Astrophysics), which is a Japanese-lead astronomical mission 

with a cryogenically cooled 3.5 m telescope optimized for mid- and far-infrared 

astronomy. With its high spatial resolution and unprecedented sensitivity in the midto 

far-infrared, SPICA can address a number of key problems in current astrophysics, 

ranging from the star-formation history of the universe to the formation of planets. To 

reduce the mass of the whole mission, SPICA carries no cryogen; SPICA will be 

launched at ambient temperature and cooled down on orbit by mechanical coolers on 

board with an efficient radiative cooling system. This combination enables a 3.5-m 

class cooled (4.5 K) telescope in space. 

European participation to SPICA was selected as one of candidate missions in ESA 

Cosmic Vision 2015-2025. Under this framework, ESA is expected to be in charge of 

the SPICA telescope, and a European consortium will develop a far-infrared focal 

plane instrument. The target year of the launch of SPICA is 2017. 

16


Invited presentation 

1-2 

Stratospheric Observatory for Infrared Astronomy (SOFIA) 

Eric Becklin, Chief Scientist 

The joint U.S. and German SOFIA project to develop and operate a 2.5-meter infrared 

airborne telescope in a Boeing 747-SP is now in its final stages of development. 

Flying in the stratosphere, SOFIA allows observations throughout the infrared and 

sub-millimeter region, with an average transmission of greater than 80%. SOFIA has 

a wide instrument complement including broadband imagers, moderate resolution 

spectrographs capable of resolving broad features due to dust and large molecules, 

and high resolution spectrometers suitable for kinematics studies of molecular and 

atomic gas lines at km/s resolution. These instruments will enable SOFIA to make 

unique contributions to a broad array of science topics. The first successful flight tests 

of the aircraft with the telescope mounted, began in 2007. First science flights will 

begin in 2009, and the observatory is expected to operate for more than 20 years. The 

sensitivity, characteristics, science instrument complement, future instrument 

opportunities and examples of first light science will be discussed. 

17



The Stratospheric TeraHertz Observatory (STO) 

C. Walker, C. Kulesa, C. Groppi, E. Young, T. McMahon (U. Arizona); P. Bernasconi, C. Lisse, D. 

Neufeld (Johns Hopkins Applied Physics Lab); D. Hollenbach (NASA Ames); J. Kawamura, P. 

Goldsmith, W. Langer, H. Yorke, J. Sterne, A. Skalare, I. Mehdi, S. Weinreb (Jet Propulsion 

Laboratory); J. Kooi (Caltech); J. Stutzski, U. Graf, C. Honingh, P. Puetz (U. Cologne); C. Martin 

(Oberlin); M. Wolfire (U. Mayland) 

The Stratospheric TeraHertz Observatory (STO) is a NASA funded, Long Duration Balloon (LDB) 

experiment designed to address a key problem in modern astrophysics: understanding the Life Cycle of 

the Interstellar Medium (ISM). STO will first survey a section of the Galactic plane in the dominant 

interstellar cooling line [C II] (158 μm) and the important star formation tracer [N II] (205 μm) at ~1 

arc minute angular resolution, sufficient to spatially resolve atomic, ionic and molecular clouds at 10 

kpc. Our mission goals for this survey are to: 

1) Determine the life cycle of Galactic interstellar gas. 

2) Study the creation and disruption of star-forming clouds in the Galaxy. 

3) Determine the parameters that affect the star formation rate in the galaxy. 

4) Provide templates for star formation and stellar/interstellar feedback in other galaxies. 

To achieve the angular resolution requirement STO will have an 80 cm aperture. In order to 

discriminate clouds in a given beam and determine their distance from Galactic rotation, STO will 

utilize a heterodyne receiver system with a resolving power, R > 10 6 . The first flight receiver will 

consist of eight, phonon-cooled HEB mixers; four optimized for the [CII] line and four for the [NII] 

line. The STO spectrometer will have sufficient bandwidth to detect all clouds participating in Galactic 

rotation in each of the 8 pixels. STO is capable of detecting every giant molecular cloud in the Galaxy, 

every HII region of significance, and every diffuse HI cloud with A V > 0.3. Once the [CII] and [NII] 

surveys are completed, we will propose to use STO to perform complementary surveys in emission 

lines of [OI], HD and the other [NII] (122 μm) line. 

In our talk we will further discuss the implementation of STO, including the instrument package, 

telescope, and gondola. 

STO Telescope and Gondola: To 

be Refurbished from APL’s Flare 

Genesis Experiment 

18


1-4 


New ground-based facilities for THz astronomy 

Gordon Stacey, Cornell University 

I will present a discussion of the present capabilities and future prospects for groundbased 

terahertz spectroscopy. My discussion will cover instrumentation, facilities and 

science. I will focus on current results from, and future plans for facilities in 

Antarctica and high sites in Chile. 

19


1-5 


CMB experiments at mm and submm wavelengths 

Paul Richards, University of California, Berkeley 

The enormous scientific rewards from measurements of the spectrum and anisotropy 

of the Cosmic Microwave Background have strongly stimulated the development of 

sensitive detector systems for mm and submm wavelengths. These included systems 

based on bolometric direct detectors, HEMT amplifiers and even SIS mixers. 

Examples will be described of small experiments that developed and evaluated 

detector systems, which later enabled the acquisition of large precise data sets from 

space observations. Modern, large format bolometric focal planes for photometry of 

the CMB will be described and compared with the sensitivity possible from ideal 

coherent receivers. 

20


Session 2 – HEB Mixers 


11:10 – 12:40 

Chair: Teun Klapwijk 

11:10 - 11:25 2-1 Terahertz heterodyne array based on S. Cherednichenko, 

NbN HEB mixers 

Chalmers Univ of 

of Technology 

11:25 - 11:40 2-2 NbZr films for THz phonon-cooled Andrey Smirnov, 

HEB mixers 

Moscow State 

Pedagogical Univ 

11:40 - 11:55 2-3 Sensitivity of a heterodyne receiver P. Khosrohpanah, 

at 4.3 THz based on a NbN hot electron SRON 

bolometer mixer 

11:55 - 12:10 2-4 Demonstration of a heterodyne receiver Wen Zhang, 

for detection of OH line at 3.5 THz Purple Mountain 

based on a superconducting HEB mixer Observatory/SRON 

and a distributed feedback quantum 

cascade laser 

12:10 - 12:25 2-5 Temperature Dependence of HEB Shoichi Shiba, 

Mixer Performance 


12:25 - 12:40 2-6 Fabrication and characterization of NbN Gregory Goltsman, 

HEB mixers with in situ gold contacts Moscow State 

Pedagogical Univ 

21


Terahertz heterodyne array based on NbN 

HEB mixers. 

2-1 

S.Cherednichenko* a , V.Drakinskiy a , B.Lecomte b , F.Dauplay b , J.-M.Krieg b , 

Y.Delorme b , A.Feret b , H.-W.Hübers c , A.D.Semenov c , G.N.Gol’tsman d , 

a Chalmers University of Technology, Physical Electronics laboratory, Department of 

Microtechnology and Nanoscience, SE-41296, Gothenburg, Sweden 

b Observatoire de Paris, LERMA, 77, Avenue Denfert-Rochereau, 75014, Paris, 

France. 

c German Aerospace Center (DLR), Institute of Planetary Research, 12489 Berlin, 

Germany. 

d Physical Department, State Pedagogical University of Moscow, 119891 Moscow, 

Russia. 

*serguei@chalmers.se 

A 16 pixel heterodyne receiver for 2.5 THz is been developed based on NbN 

superconducting hot-electron bolometer (HEB) mixers. The receiver uses a 

quasioptical RF coupling approach where HEB mixers are integrated into double 

dipole antennas on 1.5μm thick Si 3 N 4 / SiO 2 membranes. Miniature mirrors (one per 

pixel) and back short for the antenna were used to design the output mixer beam 

profile. The camera design allows all 16 pixel IF readout in parallel. The gain 

bandwidth of the HEB mixers on Si 3 N 4 / SiO 2 membranes was found to be about 

3 GHz, when an MgO buffer layers is applied on the membrane. We will also present 

the progress in the camera heterodyne tests. 

Keywords: HEB mixer, terahertz camera, NbN films, membrane, bolometer. 

22


2-2 

NbZr films for THz phonon-cooled HEB mixers. 

Andrey Smirnov, Pavel Larionov, Matvey Finkel, Sergey Maslennikov, Boris Voronov and 

Gregory Goltsman 

Moscow State Pedagogical University, Moscow 119992, Russia 

Heterodyne receivers demonstrate great potential for the detection of 

electromagnetic radiation in the terahertz frequency range. At present, these 

detectors are used to facilitate the realization of such projects like 

HERSCHEL, SOFIA, TELIS , MILLIMETRON, etc. 

Now NbN HEB mixers are the most sensitive detectors for heterodyne 

spectrometers between 1 to 6 THz. Unique characteristics make NbN HEBs 

highly attractive for both ground- and space-based telescopes. 

Important mixer parameter is the IF bandwidth. Obviously a larger IF 

bandwidth allows for simultaneous observation of several lines, or 

instantaneous measurement of a single broad line. State of the art for IF 

bandwidth of NbN HEB is about 5 GHz, however it is desirable to get wider 

bandwidth achievable. Among different methods of IF bandwidths extension 

one of the most prospective approaches is the looking for alternative 

superconducting films, which will allow improving this key parameter. This 

work is devoted to the investigation of the applicability of NbZr film as a new 

material for ultrawide bandwidth HEB mixer. In this work we tested first NbZr 

bridges and observed IF bandwidth which is comparable with that of NbN 

structure of the same dimensions and at the same RF frequency. The further 

work will be the research of electron-phonon time and escape time of 

nonequilibrium phonons for the structure with smaller thickness that will 

clarity the next perspectives of this material for HEB mixer technologies. This 

result will also be reported at the Symposium. 

23


Sensitivity of a heterodyne receiver at 4.3 THz based on a NbN hot 

electron bolometer mixer 

2-3 

P. Khosropanah 1 , W. M. Laauwen 1 , M. Hajenius 1,2 , J.N. Hovenier 2 , T. Bansal 1,2 , J. R. Gao 1,2 , and T.M. 

Klapwijk 2 

1 

SRON Netherlands Institute for Space Research, Utrecht/Groningen, the Netherlands 

2 

Kavli Institute of NanoScience, Delft University of Technology, Delft, the Netherlands 

Correspondence: P.Khosropanah@sron.nl 

Today hot electron bolometer (HEB) mixer is considered a mature technology below 2 THz as it is 

used in band 6 and 7 (1.4-1.9 THz) of HIFI on the Herschel space observatory. Future space missions 

will move to higher frequencies, e.g. 2-6 THz and thus call for sensitive mixers beyond 2 THz. 

Additionally, the successful demonstration of the new technology will play a crucial role in defining 

ESA/NASA future mission plans. 

We have studied the sensitivity of a superconducting NbN hot electron bolometer mixer integrated with 

a spiral antenna. Using hot/cold blackbody loads and a beam splitter all in vacuum and applying an 

optically pumped gas laser at 4.3 THz as a local oscillator (LO), we measured a double sideband (DSB) 

receiver noise temperature of 1300 K at the optimum LO power of 330 nW and a bias voltage of 0.8 

mV [1], which is an unprecedented sensitivity at such a high frequency and is about 12 times the 

quantum noise (hν/2k B ). By comparing to the measurement in a usual setup, we find that the use of 

vacuum setup not only reduces the loss in the air and the window, but also reduces the fluctuations 

considerably, which makes the measurement much more reliable (see the figure, which shows the 

receiver output power and receiver noise temperature versus bias voltage in the vacuum and in the 

usual setup). 

The LO power fluctuations caused by either the power fluctuations of the laser itself or by air and beam 

splitter vibrations can have a significant impact on the stability of a receiver. Although this is usually 

not the case in a real astronomical instrument, such fluctuations can inevitably occur in the laboratory 

environment where a gas laser is applied as LO. Here we also introduce a new measurement method 

that can accurately determine the receiver noise temperature despite of LO power fluctuations or drift. 

[1] P. Khosropanah, J. R. Gao, W. M. Laauwen, M. Hajenius, and T. M. Klapwijk, “ Low noise NbN 

hot electron bolometer mixer at 4.3 THz”, Appl. Phys. Lett. 91, 221111 (2007). 

Receiver output power (dBm) 

-20 

-22 

-24 

-26 

-28 

-30 

-32 

Air 

Vacuum 

Air 

Vacuum 

Hot Load 

Cold Load 

-4 -3 -2 -1 0 1 2 3 4 

Voltage (mV) 

12000 

10000 

8000 

6000 

4000 

2000 

0 

DSB receiver noise temperature (K) 

24


2-4 

Demonstration of a heterodyne receiver for detection of OH line at 3.5 

THz based on a superconducting HEB mixer and a distributed feedback 

quantum cascade laser 

W. Zhang 1,a , P. Khosropanah 1 , J.N. Hovenier 2 , J.R. Gao 1,2 , T. Bansal 1,2 , M. Hajenius 1,2 , T.M. 

Klapwijk 2 , M.I. Amanti 3 , G. Scalari 3 , and J. Faist 3 

1 SRON Netherlands Institute for Space Research, Utrecht/Groningen, The Netherlands 

2 Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands 

3 Institute of Physics, University of Neuchâtel, 1 A.-L. Breguet, Neuchâtel CH–2000, Switzerland 

Problems related to the Earth's atmosphere such as global warming and ozone destruction 

can be monitored and better understood by observations in the far-infrared regime. This 

regime holds the most important spectral signatures of the relevant molecules. Hydroxyl (OH) 

molecules at 1.8, 2.5 and 3.5 THz have been identified as being crucial. Among them, the OH 

line at 3.5 THz should have the highest intensity and is well isolated from other molecular 

lines. Therefore, it is ideal for monitoring and retrieval. 

THz quantum cascade lasers (QCLs) are currently the only choice of solid-state local 

oscillators (LO) for this specific frequency since solid state LOs based on multipliers are 

unable to deliver enough power and gas lasers have no strong line. Although THz QCLs 

based on Fabry-Pérot cavity have been demonstrated as LOs for the Y-factor measurement, 

for this purpose a QCL with a stable single-mode emission at a precisely designed wavelength 

is desirable. Distributed feedback (DFB) QCLs, which are based on first-order Bragg gratings 

incorporated into the waveguide, are able to offer a reliable method to achieve required 

single-mode operation. 

Here we report heterodyne measurements using a surface plasmon DFB QCL emitted at 

3.42 THz as a LO and an NbN HEB mixer integrated with a tight spiral antenna [1]. The 

QCLs were developed by University of Neuchâtel. First, we demonstrate that the DFB QCL, 

after improving the beam [2], can pump the HEB mixer with a 3 μm-thick Mylar beam 

splitter. Second, we succeeded in measuring receiver noise temperatures (see the figure). 

Although the best receiver noise 

temperature is 2700 K at 3.42 

THz, this value can be improved 

considerably by optimizing the 

setup, such as using an 

antireflection coating Si lens. 

Third, we illustrate a few 

aspects of this DFB QCL which 

needs to be improved 

significantly. For example, the 

high input power imposes a 

challenge to operate this laser at 

L-He temperature. 

This is an ongoing 

experiment. So we will report 

the latest results during the 

symposium. 

DSB Trec(K) 

10000 

8000 

6000 

4000 

2000 

0.8mV1.2mV 

1.6mV 

0.6mV 1.0mV 1.4mV 1.8mV 

0.01 0.02 0.03 0.04 0.05 0.06 

Current(mA) 

a On leave from Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, 210008, China 

[1] P. Khosropanah, J. R. Gao, W. M. Laauwen, M. Hajenius and T. M. Klapwijk, Appl. Phys. Lett. 91, 

221111 (2007). 

[2] J.N. Hovenier, S. Paprotskiy, J.R. Gao, P. Khosropanah, T.M. Klapwijk, L. Ajili, M. A. Ines, and J. 

Faist, Abstract, ISSTT 2007. 

25


2-5 

Temperature Dependence of HEB Mixer Performance 

Shoichi Shiba a , Ken Shimbo a , Ling Jiang a , Nami Sakai a , Mika Sugimura a , 

Hiroyuki Maezawa b , and Satoshi Yamamoto a 

a Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan 

b STE Laboratory, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan 

We are developing a hot-electron bolometer (HEB) mixer receiver for astronomical 

observations in the terahertz region, which will be used for the ground-based 

observations from high altitude sites. We have fabricated the two types of the HEB 

mixers, a diffusion cooled mixer using Nb and a phonon cooled mixer using NbTiN, 

in our laboratory, and have carried out their critical evaluations. 

For the NbTiN HEB mixer, we optimized the fabrication condition of the NbTiN 

film on the Z-cut crystalline quartz substrate. The film was deposited at the room 

temperature by using the RF plasma assisted sputtering of the NbTi target under the 

N 2 /Ar buffer gas. In this case, the T c value is very sensitive to the N 2 concentration in 

the buffer gas. Therefore the N 2 flow rate was carefully optimized for the thin film, 

and finally the best T c value of 9.8 K was obtained for the 5 nm thick film. This T c 

value is fairly good for the room temperature deposition. 

We fabricated the HEB mixers with a combination of lift-off and etching processes. 

First, the HEB structure is formed with a bilayer of Au/Nb or Au/NbTiN on the quartz 

substrate without breaking vacuum. This ensures a good electric contact between the 

two layers without suffering from natural oxidation of the superconductor surface. 

Then the Au layer on the microbridge part is removed by the Ar plasma etching. 

The evaluation of the HEB mixer is carried out at 810 GHz using a waveguide-type 

mixer block. The mixer is cooled down to 4 K by a two-stage GM refrigerator. We 

measured the noise temperatures by using the Y-factor method. The highest Y-factor 

obtained for the NbTiN mixer is 0.65 dB at the IF frequency of 1.1 GHz, which 

corresponds to the receiver noise temperature of 1300 K. As for the Nb device, the 

highest Y-factor of 0.3 dB is obtained. 

The bath temperature dependence of the Y-factor was also measured for the NbTiN 

mixer by using an electric heater attached to the cold head of the refrigerator. The Y- 

factor becomes lower for the higher bath temperature. However, it is almost constant 

below 6 K, if the bias current is adjusted to the optimum point by changing the LO 

input power. This behavior means that the bath temperature is not a very critical issue 

for practical operation of the mixer for astronomical observations. Further analyses 

on the temperature dependence of the performance are now in progress. In addition, 

we will discuss a possible difference in the temperature dependence between the 

NbTiN and Nb based mixers. 

26


Fabrication and characterization of NbN HEB mixers with in situ gold contacts 

G. N. Goltsman, N. S. Kaurova, S. A. Ryabchun, I. V. Tretyakov, M. I. Finkel, S. N. 

Maslennikov, B. M. Voronov. 

Moscow State Pedagogical University, Moscow 119992, Russia 

We present recent results on the fabrication and performance of NbN HEB mixers 

with in situ gold contacts. The IF bandwidth amounts up to 6 GHz for 3.5 nm thick 

NbN film on plane Si substrate with in situ contacts in comparison to 3.5 GHz for 

the device based on the same film but with ex situ gold lift-off process involved in 

the contacts fabrication. The increase in the IF bandwidth is attributed to the 

additional diffusion cooling through improved contacts. The IF bandwidth 

dependence on the bridge length is being investigated and will be also presented. 

The uncorrected noise temperature of NbN heterodyne receiver at LO frequency of 

2.5 THz amounts to 900 K. 

2-6 

27


28


Session 3 – SIS Mixers 


14:00 – 15:45 

Chair: Sheng-Cai Shi 

14:00 - 14:15 3-1 Low noise 1.4 THz SIS mixer for SOFIA Alexandre Karpov, 

Caltech 

14:15 - 14:30 3-2 Development of an All-NbN Waveguide Jing Li, 

SIS Mixer for 0.5 THz 

Purple Mountain 

Observatory 

14:30 - 14:45 3-3 A novel THz SIS mixer with a Akira Endo, NAOJ / 

NbTiN-groundplane 


14:45 - 15:00 3-4 Design and Performance of Waveguide Wenlei Shan, 

Mixers with All NbN tunnel junctions on Purple Mountain 

MgO substrates 

Observatory 

15:00 - 15:15 3-5 Bandwidth of Nb/AlN/Nb SIS mixers Chris Lodewijk, 

suitable for frequencies around 700 GHz Delft University of 

Technology 

15:15 - 15:30 3-6 RF Performance of a 600 - 720 GHz Patricio Mena, 

Sideband-Separating Mixer with SRON / University 

All-Copper Micromachined Waveguide of Groningen 

Mixer Block 

15:30 - 15:45 3-7 100 GHz sideband separating mixer Doris Maier, 

with wide IF band: First results 

IRAM 

29


Low noise 1.4 THz SIS mixer for SOFIA 

3-1 

A. Karpov, D. Miller, J. A. Stern*, B. Bumble*, H. G. LeDuc*, J. Zmuidzinas 

California Institute of Technology, Pasadena, CA 91125, USA 

* Jet Propulsion Laboratory, Pasadena, CA 91109, USA 

We report on the development of a 1.4 THz SIS mixer. The mixer uses SIS junctions 

made off Nb/Al-AlN/NbTiN. The junction area is 0.24 μm 2 and the R N A= 6 Ohm μm 2 . 

The junctions are diamond-like shaped in order to optimize the suppression of the 

Josephson DC currents. We are using a double slot planar antenna to couple the mixer 

chip with the telescope beam. The matching microcircuit is made of Nb and gold. The 

on-chip coupling prediction is plotted below in the Fig. 1. The mixer is expected to 

provide a low noise operation in a 1.3 – 1.5 THz receiver. The mixer IF circuit is 

designed to cover 4 - 8 GHz band. 

The 1.3-1.5 THz SIS mixer is aimed for the 1.4 Terahertz channel of the Caltech 

Airborne Submillimeter Interstellar Medium Investigations Receiver (CASIMIR). It is 

a far-infrared and submillimeter heterodyne spectrometer, designed for the 

Stratospheric Observatory For Infrared Astronomy, (SOFIA). The goal of this work is 

to provide a low noise spectrometer particularly for the studies of the H 2 D + 1 01 - 0 00 

line around 1370 GHz. 

The mixer test with a limited LO power allows us to make an estimation of very good 

receiver performance with a higher LO levels (fig.2). The mixer test with a more 

powerful LO source is under way and will be presented. 

0.7 

0.6 

0.5 

Model prediction 

1.4 THz 

mixer design 

Coupling 

0.4 

0.3 

0.2 

0.1 

Fig. 1 

0 

0 500 1000 1500 2000 

LO Frequency (GHz) 

Fig. 2. 

Receiver noise (K) 

6000 

5000 

4000 

3000 

2000 

1000 

0 

Expected receiver performance and measured 

conversion gain (a.u.) 

SIS mixer 

gain (a.u.) 

0 10 20 30 40 

LO Induced Current (uA) 

30


Development of an All-NbN Waveguide SIS Mixer for 0.5 THz 

Jing Li 1,3 , Masanori Takeda 2 , Zhen Wang 2 , and Sheng-Cai Shi 1 

1. Purple Mountain Observatory, NAOC, CAS, China 

2. Kobe Advanced ICT Research Center, NiCT, Japan 

3. Graduate School of Chinese Academy of Science, CAS, China 

2 West Beijing Road, Nanjing Jiangsu 210008, China 

Tel: +86-25-8333-2229; Fax: +86-25-8333-2206 

E-mail: lijing@mail.pmo.ac.cn, scshi@mail.pmo.ac.cn 

3-2 

With a gap frequency double that of Nb-based SIS junctions (~0.7 THz), NbN SIS 

junctions [1] are of particular interest for the development of heterodyne mixers at 

frequencies beyond 1 THz. To demonstrate the feasibility of NbN SIS mixers for real 

astronomical applications, we firstly develop an all-NbN waveguide SIS mixer at a 

relatively low frequency of 0.5 THz. In this paper, we will focus mainly on the 

introduction of the mixer design, NbN junction fabrication and mixer performance. In 

addition, its LO-power requirement, IF bandwidth, and IF-output-power stability will be 

compared with another 0.5-THz SIS mixer adopting Nb twin junctions. This all-NbN SIS 

mixer has been already installed on the POST submillimeter-wave telescope [2] for the 

observations of two selected spectrum lines, namely, the CO (J=4-3) molecular line at 

0.46 THz and the neutral carbon line at 0.49 THz. Some testing observation results will 

be presented. 

[1] Z. Wang, A. Kawakami, Y. Uzawa, and B. Komiyama, “NbN/AlN/NbN tunnel 

junctions fabricated at ambient substrate temperature”, IEEE Trans. Appl. Supercond., 

vol. 5, no. 2, pp. 2322~2325, 1995. 

[2] S.P. Huang, J. Li, A.Q. Cao, S.H. Chen, X.F. Shen, Z.H. Lin, S.C. Shi, and J. 

Yang, “Development of a Compact 500-GHz SIS Receiver,” Proc. of AP-RASC04, 

pp. 412-413, 2004. 

31


A novel THz SIS mixer with a NbTiN-groundplane and SIS micro-trylayers 

directly grown on a quartz substrate 

A. Endo 1,2,3 , T. Noguchi 3 , M. Kroug 3 , S. V. Shitov 3,4 , W. Shan 5 , T. Tamura 3 , 

T. Kojima 3,6 , Y. Uzawa 3 , T. Sakai 3 , H. Inoue 1 , K. Muraoka 1,2 , K. Kohno 1 

1 IoA, Univ. of Tokyo; 2 JSPS Research Fellow; 3 NAOJ; 4 IREE; 5 PMO; 6 Osaka Pref. Univ. 

3-3 

It is common to adopt superconductors with large gap energies (e.g., NbTiN, NbN) or normal metals with 

low resistivity (e.g., Al) as materials for the transmission lines of SIS mixers that operate above the gap 

frequency of Nb (~0.7THz). However, these materials are not necessarily the best materials for fabricating 

good quality SIS junctions. Therefore, a combination of SIS junctions and transmission lines made of 

different materials is a potent candidate in designing a THz-SIS mixer. For example, a combination of Nb 

SIS junctions with a NbTiN/Al microstripline can show good performance at above 1THz[1]. Usually, 

these mixers are fabricated by depositing an SIS-trilayer on top of the groundplane. In such a configuration, 

the requirements on the film quality of the grounplane tend to be relatively tight, if both good quality SIS 

junctions and a low-loss transmission line are to be realized. There is also a potential problem of heat 

trapping in the junction placed on a superconductor with a higher gap energy[2]. 

We propose an alternative structure and fabrication process for such multi-material SIS mixers. In this 

design, both the µm-sized SIS trilayers and the groundplane are deposited directly onto the quartz substrate, 

or possibly with a buffer layer in between (Fig1). This structure is expected to possess a number of unique 

features, for example: 

• The quality of the SIS junction is less affected by the physical nature of the groundplane film. 

• The heat can escape directly from the junction into the substrate. 

We have investigated the influence of this structure on the junction quality and circuit characteristics, by 

means of numerical calculation and experiment. Numerical calculation suggests that the effect of the extra 

resistance around the junction is tolerable in terms of noise performance, if the width of the gap is ≤0.5µm. 

SIS mixers based on this structure have been fabricated using Nb/Al-AlOx(or AlNx)/Nb SIS junctions and 

NbTiN/Al microstriplines (Fig. 2). The junction quality is comparable to that of all-Nb devices (Fig. 3), 

suggesting that the junction quality is less affected by the groundplane properties. These SIS mixers will be 

tested for possible application in the Band 10 receiver (787-950 GHz) of ALMA (Atacama Large 

Millimeter and submillimeter Array)[3], as well as the upcoming 800GHz-band dual polarization receiver 

(AERO) for the ASTE (Atacama Submillimeter Telescope Experiment). 

FIG. 1. Cross sectional geometry of the SIS mixer 

with a micro-trylayer. 

FIG. 2. SEM micrograph of a twin-junction. 

The diameter of the junction is 1µm. 

FIG. 3. dc I(V) curve of an Nb/Al-AlN x /Nb 

SIS junction with NbTiN/Al microstripline 

[1] Jackson et al., APL 97, 113904 (2005) 

[2] Leone et al., APL 76, 780 (2000) 

[3] Shan et al., IEEE Trans. Appl. Supercond. 17, 363 (2007) 

32


3-4 

Design and Performance of Waveguide Mixers with All NbN 

tunnel junctions on MgO substrates 

Wenlei Shan 1 , Masanori Takeda 2 , Kojima Takafumi 3,4 , Yoshinori Uzawa 3 , Shengcai Shi 1 , 

and Zhen Wang 2 

1. Purple Mountain Observatory, 2 West Beijing Road, Nanjing 210008, China 

2. Kansai Advanced research Center, National Institute of Information and Communications 

Technology, Iwaoka 588-2, Iwaoka-cho, Nishi-ku, Kobe, 651-2492, Japan 

3. National Astronomical Observatory of Japan, Mitaka, Tokyo, 181-8588, Japan 

4. Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-Cho, Sakai, Osaka, 

599-8531, Japan 

Low noise waveguide mixers with all NbN tunnel junctions on MgO substrate have been 

developed approaching (0.78-0.95THz). For the first time, such waveguide mixers were 

experimentally verified to be as good as their quasi-optical counterparts in sensitivity. 

Improvements are likely in virtue of high quality NbN film as well as an effective waveguide probe 

design that has following properties. First, the waveguide probe works in a full height waveguide to 

minimize the waveguide loss. Second, the design makes use of a resonance choke filter on MgO 

substrate with a thickness of 35 micrometers desirable for convenient and accurate mounting, 

which can effectively block the signal from leaking to IF port. Third, the low impedance of such a 

probe is close to that of the SIS junction resulting reduced loss by not using a quarter-wavelength 

impedance transformer. As for the mixing element, both half-wavelength self-compensating 

distributed SIS junction and parallel-connected twin-junction (PCTJ) are designed and evaluated. 

Measurement results show that the PCTJ mixer is superior in both gain and noise likely due to 

smaller loss in the tuning circuit. 

33


3-5 

Bandwidth of Nb/AlN/Nb SIS mixers suitable for frequencies around 700 GHz 

C. F. J. Lodewijk, E. Van Zeijl, T. Zijlstra, D. N. Loudkov, and T. M. Klapwijk 

Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology 

Lorentzweg 1, 2628 CJ Delft, The Netherlands 

F. P. Mena and A. M. Baryshev 

SRON Netherlands Institute for Space Research and Kapteyn Astronomical Institute, 

Landleven 12, 9747 AD Groningen, The Netherlands 

High critical current density superconducting tunneljunctions with an AlN barrier have a 

better quality compared to AlOx devices due to a better uniformity of the barrier 

transmissivity 1 . We have developed a new fabrication process for AlN barriers with a better 

reproducibility and control compared to previous work, enabling the exploitation of these 

barriers in superconductor-isolator-superconductor (SIS) mixers. 

Although the specifications for Band 9 (602 to 720 GHz) of the atmospheric window at the 

Atacama Large Millimeter Array (ALMA) can be met with AlOx, an intrinsically wider 

band coverage would be beneficial. High critical current density AlN devices have a lower 

RC time, allowing such a desirable larger bandwidth, providing a well-designed matching 

circuit 2 . 

We report on results with Nb/AlN/Nb SIS mixers for ALMA Band 9, demonstrating 

their wide bandwidth behavior with Fourier Transform Spectrometer (FTS) measurements. 

These measurements have been performed in air and reveal that the bandwidth of the AlN 

devices is no longer intrinsically limited by the barrier. Instead, the electromagnetic 

environment, through both the atmospheric absorption of radiation (due to the presence of 

water) and the antenna impedance, determines the frequency response. 

We will also present noise temperature measurements of AlN SIS mixers that 

complement the FTS results. The noise temperature reaches record low values in an 

unprecedented broad frequency range around 600 to 720 GHz, easily satisfying the 

requirement for ALMA Band 9. 

The wideband performance of the AlN devices relaxes the fabrication and alignment 

difficulties that accompany the use of AlOx SIS devices for Band 9. With AlN, the 

technical requirements can more easily and more consistently be met. 

1 T. Zijlstra, C. F. J. Lodewijk, N. Vercruyssen, F. D. Tichelaar, D. N. Loudkov, and T. M. Klapwijk, 

“Epitaxial aluminum nitride tunnel barriers grown by nitridation with a plasma source”, Appl. Phys. Lett., 

Vol. 91, 233102 (2007). 

2 C. F. J. Lodewijk, O. Noroozian, D. N. Loudkov, T. Zijlstra, A. M. Baryshev, F. P. Mena, and T. M. 

Klapwijk, “Optimizing superconducting matching circuits for Nb SIS mixers operating around the gap 

frequency”, IEEE Trans. Appl. Superconductivity, Vol. 17, 375 (2007). 

34


3-6 

RF Performance of a 600 - 720 GHz Sideband-Separating Mixer 

with All-Copper Micromachined Waveguide Mixer Block. 

F.P. Mena 1 , J. Kooi 2 , A.M. Baryshev 1 , C.F.J. Lodewijk 3 , T.M. Klapwijk 3 , and W. Wild 1 

1 SRON Netherlands Institute for Space Research and Kapteyn Astronomical Institute, University of 

Groningen, Landleven 12, 9747 AD Groningen, The Netherlands. 2 California Institute of Technology, MS 

320-47 Pasadena, California 91125, USA. 3 Kavli Institute of Nanoscience, Delft University of Technology, 

Lorentzweg 1, 2628 CJ Delft, The Netherlands. 

V. Desmaris, D. Meledin, A. Pavolotsky, and V. Belitsky 

Chalmers University of Technology, Group for Advanced Receiver Development, Department of Radio and 

Space Science with Onsala Space Observatory, SE 412 96, Gothenburg, Sweden 

A sideband-separating (2SB) mixer has several advantages over its double sideband (DSB) counterpart. 

Despite those advantages, its implementation at high frequencies is rather challenging as a more complex 

design is needed. In fact, the required waveguide circuitry becomes extremely difficult to fabricate 

employing traditional machining. Previously, we have demonstrated state-of-art performance of a 2SB mixer 

for 600 – 720 GHz band constructed exclusively by traditional machining [1]. In order to build such mixer 

one needs to produce a waveguide hybrid with a minimum branch width of 71 µm made with accuracy of 

better than 5 µm. However, traditional mechanical milling fails to deliver the required accuracy of the 

dimensions in a reproducible way. 

Here we report the performance of a 2SB mixer suitable for, e.g., ALMA Band 9 fabricated using our 

cutting-edge microfabrication technique [2], which meets the requirements for the dimension accuracy along 

with surface quality. It, moreover, allows the fabrication of the waveguide components with high yield and 

repeatability. This approach combines lithographical copper micromachining [3] for making the very fine 

waveguide structures while allowing regular milling of the remaining not critical mixer parts (Fig. 1). 

At the conference, we will present the complete results of the RF performance of the 2SB mixer. 

Fig. 1. CAD generated (left) – and SEM images (right) of the 600 – 720 GHz 2SB mixer block. 

References 

[1] F. P. Mena, J. W. Kooi, A. M. Baryshev, C. F. J. Lodewijk, R. Hesper, W. Wild, and T. M. Klapwijk, 

“Construction of a Side-Band-Separating Heterodyne Mixer for Band 9 of ALMA”, ISSTT 2007. 

[2] V. Desmaris, D. Meledin, A. Pavolotsky, and V. Belitsky, “Sub-Millimeter and THz Micromachined All- 

Metal Waveguide Components and Circuits” – submitted to the IEEE Microwave and Wireless Components 

Letters. 

[3] A. Pavolotsky, D. Meledin, C. Risacher, M. Pantaleev, and V. Belitsky, “Micromachining approach in 

fabricating of THz waveguide components,” Microelectronics Journal, vol. 36, pp. 683-6, 2005. 

35


3-7 

100 GHz sideband separating mixer with wide IF band: 

First results 

D. Maier, D. Billon-Pierron, J. Reverdy, and M. Schicke 

Institut de RadioAstronomie Millimétrique (IRAM) 

300, rue de la piscine 

38406 St. Martin d’Hères 

France 

We are reporting on the design of a sideband separating SIS mixer covering the rf 

frequency range from 80 to 116 GHz. The mixer consists of a waveguide rf quadrature 

hybrid coupler, two DSB mixers and an IF hybrid coupler. Rf coupler, LO couplers, LO 

splitter and mixer blocks have been integrated into one e-plane split-block. The DSB 

mixers consist of Nb-Al/AlO x -Nb junctions integrated in Nb tuning structures. Because 

of the low capacitance of the mixer chip it works for IF frequencies from 4 to 12 GHz. 

Although in the final design the junctions are directly mounted into the integrated 

coupler/mixer block without prior testing, mixer blocks have been fabricated to be able to 

validate the mixer design by DSB mixer tests. Those tests confirmed that the design 

covers both rf and IF design frequency bands obtaining good and flat noise temperatures. 

First 2SB mixer tests showed good noise temperatures and image rejections. 

36


Session 4 – Herschel-HIFI 


16:10 – 17:50 

Chair: Thijs de Graauw 

16:10 - 16:35 4-1 The Herschel Mission and Key Göran Pilbratt, ESA 

Programmes (Invited) 

16:35 - 16:50 4-2 Performance of the superconducting Gert de Lange, 

mixers for the HIFI instrument 


16:50 - 17:05 4-3 HIFI Flight Model Testing at Instrument Pieter Dieleman, 

and Satellite Level 


17:05 - 17:20 4-4 HIFI Instrument Stability as measured Jacob Kooi, 

during the ILT phase: Results and Caltech 

operational impacts 

17:20 - 17:35 4-5 Flight Attenuators for the HIFI Local Willem Jellema, 

Oscillator Bands 


17:35 - 17:50 4-6 HIFI Pre-launch Calibration Results David Teyssier, 

ESA 

18:00 - 19:00 Poster Session and Reception 

37


4-1 


Herschel Mission Overview and Key Programmes 

Göran L. Pilbratt 

Herschel Project Scientist 

European Space Agency 

The Herschel Space Observatory is the next observatory mission in the 

European Space Agency (ESA) science programme. It will perform imaging 

photometry and spectroscopy in the far infrared and submillimetre part 

of the spectrum, covering approximately the 55-672 micron range. 

Herschel will carry a 3.5 metre diameter passively cooled telescope. The 

science payload complement - two cameras/medium resolution spectrometers 

(PACS and SPIRE) and a very high resolution heterodyne spectrometer 

(HIFI) - will be housed in a superfluid helium cryostat. The HIFI 

instrument is using superconducting SIS and HEB mixers, and both AOS and 

auto-correlator spectrometers. The ground segment will be jointly 

developed by the ESA, the three instrument teams, and NASA/IPAC. 

Once operational in orbit around L2 after a launch in 2008 and followed 

by an early operations period of 6 months, Herschel will offer a minimum 

of 3 years of routine science observations. The key science objectives 

emphasize current questions connected to the formation and evolution of 

galaxies, stars and stellar systems, including our own planetary system. 

Nominally ~20,000 hours will be available for astronomy, 32% is 

guaranteed time and the remainder is open to the general astronomical 

community through a standard competitive proposal procedure. 

The Key Programme AO was issued in Feb 2007, and both the guaranteed and 

open time accepted Key Programmes will be discussed, as well as future 

observing opportunities. 

38


4-2 

Performance of the superconducting mixers for the HIFI 

instrument 

Gert de Lange [a] , Jean-Michel Krieg [b] , Netty Honingh [c] , 

Alexandre Karpov [d] , Sergey Cherednichenko [e] 

[a] SRON Netherlands Institute for Space Research, Groningen, The Netherlands 

[b] LERMA, Paris, France 

[c] KOSMA, Cologne, Germany 

[d] Caltech, Pasadena, USA 

[e] Chalmers, Gothenburg, Sweden 

After several years of development and qualification, the HIFI instrument for 

the Herschel Space Observatory (HSO) is now at the final stage of integration 

and testing. The launch of HSO together with Planck is scheduled for Oct 

2008. Once in orbit Herschel will provide a unique window to the submillimeter 

and THz frequency range. This frequency range is largely obscured 

for ground based astronomy due to the presence of water vapour in the 

earth’s atmosphere. Herschel/HIFI will therefore make it possible to do 

detailed spectroscopic studies of water lines in the star forming regions of our 

galaxy. 

The Herschel Space Observatory will fly two cameras/medium resolution 

spectrometers (PACS and SPIRE) and the heterodyne instrument HIFI. An 

international consortium led by the PI institute, SRON, is building HIFI. 

Within HIFI, 7 heterodyne frequency bands cover the spectral range from 

480-1250 GHz (SIS mixers) and 1.41-1.91 THz (HEB mixers). Each of these 

bands contains two mixers to measure both signal polarizations 

simultaneously. The mixer units are built by groups from LERMA (France), 

KOSMA (Germany), SRON (Netherlands), Caltech/JPL (USA), and 

Chalmers/JPL (Sweden/USA). For frequencies up to 1.1 THz, waveguides and 

corrugated horns are used to couple the radiation to the superconducting 

mixers. The higher frequency bands make use of planar antennas in 

combination with silicon lenses. 

For the SIS mixer bands combinations of Nb, NbTiN, ALOx, and AlN junction 

technologies are used to optimize the performance within a specific 

frequency band. The HEB bands use phonon cooled Nb bolometers that have 

been optimized for noise performance, low LO-power consumption and 

durability. 

In the paper we discuss the design and performance of the HIFI Flight Model 

mixer units. We will present the excellent state-of-the-art sensitivities and 

the specific design issues that played a role in the development of the 

satellite hardware. 

39


4-3 

HIFI Flight Model Testing at Instrument and Satellite Level 

Pieter Dieleman, Willem Luinge et al. 

SRON Netherland Institute for Space Research 

Groningen, the Netherlands 

HIFI, the Heterodyne Instrument for the Far-Infrared is one of three 

instruments on board the ESA Herschel mission, planned for launch in 

2008. The HIFI flight model has been delivered to ESA in July 2007. 

Between December 2006 and June 2007 a test series was performed on the 

integrated HIFI instrument of which the data is now analyzed. In this 

report the test instrumentation and main features of the instrument are 

discussed, including both the wanted and less expected results. Overall 

the sensitivity of the instrument is excellent. We will briefly discuss 

the “surprises” found during the test phase of HIFI and will highlight 

one particular example: unwanted feedback in the amplification circuit. 

40


HIFI Instrument Stability as measured during the 

ILT phase: Results and operational impacts. 

4-4 

J. W. Kooi, V. Ossenkopf, M. Olberg, R. Shipman, and R. Schieder. 

HIFI, the high resolution far infrared heterodyne instrument for ESA's Herschel satellite consists of seven 

dual polarization sensitive mixer bands, and fourteen local oscillator channels. It is without a doubt the 

most complex and unique heterodyne instrument ever put together. To facilitate observation efficiency, 

optimal baseline quality, to verify instrument performance, obtain operational knowledge, to provide input 

parameters to Hspot 1 (V. Ossenkopf et al.), and efficiency computation/loop-optimization for the AOT’s 2 , 

we have investigated the HIFI instrument IF stability, system stability, differential stability, LO and IF 

warm up time, and parametric stability. The four phases of the ILT test campaign are shown graphically in 

Fig. 1 

. 

IF 

Stability 

System 

Stability 

IF Amplifier Warm-up 

Total Power Stability WBS, HRS 

Spectroscopic Stability WBS, HRS 

LO Warm-up 

Total Power Stability 

Spectroscopic Stability 

Differential 

Stability 

Parametric 

Stability 

LO Warm-up 

Load-Chop 

Internal Load 

Beam Switching 

Frequency switching 

B6, B7 Stability as a function of Vbias 

B6, B7 Stability as a function of LO Pump current 

B5 Stability as a function of B-field. 

Fig 1. Overview of the stability test during the FM ILT. The differential stability alone consists of 

4 modes of operation: Load-chop, internal load calibration measurements, beam switching, and frequency 

switching. 

During the course of the ILT campaign it was found that excess noise from the local oscillators (LO) 

severely impacted the stability of the HIFI instrument. The problem was traced to power amplifiers in the 

LO chain not being driven hard enough into saturation. This resulted in succeeding multiplier stages being 

driven away from optimal operating regimes, significantly enhancing LO excess (AM) noise. The addition 

of optical attenuators in the LO-mixer path solved most of the instability problems, however, due to the 

large dynamic range (up to 10 dB) of some of the LO output signals (notably B3a, B6, B7) it was not 

possible to optimize the amount of attenuation needed without loss in frequency coverage. Thus a 

compromise between frequency coverage and optical attenuation (stability) had to be made. 

Complicating the situation even further is that the local oscillator (LO) injection in HIFI is accomplished 

via quasi-optical beamsplitters (SIS mixer bands 1, 2, 5) and diplexers (SIS mixer bands 3, 4, and HEB 

mixer bands 6, 7). Especially in the diplexer bands we find evidence of stability degradation, due to LOU 

and FPU cryostat induced microphonic LO-mixer standing wave modulation. 

In the talk we present an overview of the measured SIS and HEB stability results, IF and LO time 

constants, and how they impact baseline quality and observation efficiency. 

1 Herschel observation planning tool 

2 Astronomical Observation Template 

41


4-5 

Flight Attenuators for the HIFI Local Oscillator Bands 

Willem Jellema 1,2 , Marcel Bruijn 3 , Jan-Joost Lankwarden 3 , Marcel Ridder 3 , Herman 

Jacobs 3 , Wolfgang Wild 1,2 and Stafford Withington 4 on behalf of the HIFI attenuator 

team 

1 SRON Netherlands Institute for Space Research, P.O. Box 800, 9700 AV, Groningen, the Netherlands 

2 Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, 9700 AV, Groningen, the 

Netherlands 

3 SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA, Utrecht, the Netherlands 

4 Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United 

Kingdom 

During the flight instrument level tests of HIFI it became clear that the instrument 

performance suffered from LO related instabilities. Because the actual LO power 

requirements of the flight mixers appeared to be an order of magnitude smaller than 

specified, the LO subsystem was forced to be operated outside its rated and stable 

operating regime. In order to push the LO power amplifiers back into normal and 

saturated operation, broadband optical attenuation in all LO bands of around 4 dB up to 

18 dB appeared necessary. 

In this paper we present the design and development of broadband optical attenuators 

from first ideas and principles, demonstration, development to space-qualification, flight 

production, performance characterization and post-delivery to Herschel-HIFI. The asbuilt 

attenuators are based on thin Ta films on robust alumina substrates and in a few 

cases combined with an AR-coating based on a polyimid spinning process. We conclude 

by presenting the attenuator flight performance, which can be tuned within a few tenths 

of a dB from target, and essentially provide a flat frequency response from 500 GHz up 

to more than 2 THz at cryogenic conditions. 

42


4-6 

HIFI Pre-launch Calibration Results 

D. Teyssier 1 , N. Whyborn 2 , W. Luinge 2 , W. Jellema 2 , P. Dieleman 2 , P. Morris 3 

1 European Space Agency 

2 SRON Netherlands Institute for Space Research 

3 

JPL 

on behalf of the HIFI calibration working group 

In this talk we will present the ground calibration campaign of the HIFI FM 

instrument at the SRON-Groningen premises. This campaign has been conducted 

over more than a year and a half, with a core period of 9 months where the 

complete flight model was available in the laboratory. The calibration of the 

instrument has been organised according to 5 main topics: i) spectral calibration, ii) 

beam characterisation (see contribution from W. Jellema to this conference), iii) 

photometry calibration, iv) stability (see contribution 4-4 from J.W. Kooi to this 

conference), v) observing modes. 

We will present here the strategy used in each of these activities and give the first 

outcomes of the campaigns, especially in the perspective of the future calibration of 

the astronomical data, and how these results will be propagated onto the flight early 

and routine activities. 

43


44


Session 5 – Direct Detectors 


08:30 – 10:15 

Chair: Jian-Rong Gao 

08:30 - 08:45 5-1 Lumped Element Kinetic Inductance Simon Doyle, 

Detectors for Far Infrared Astronomy Cardiff University 

08:45 - 09:00 5-2 Antenna coupled Kinetic Inductance Stephen Yates, 

Detectors for space based sub-mm SRON 

Astronomy 

09:00 - 09:15 5-3 Antenna-coupled Microwave Kinetic Anastasios Vayonakis, 

Inductance detectors (MKIDs) for mm Caltech 

and submm imaging arrays 

09:15 - 09:30 5-4 Contribution of dielectrics to frequency Rami Barends, 

and noise of NbTiN superconducting Delft University of 

resonators 

Technology 

09:30 - 09:45 5-5 Microstrip-coupled TES bolometers Damian Audley, 

for CLOVER 

Univ of Cambridge 

09:45 - 10:00 5-6 Superconducting transition detectors Panu Helistö, VTT 

as thermal power amplifiers for 

cryomultiplexing 

10:00 - 10:15 5-7 A Parallel/Series Array of Leonid Kuzmin, 

Superconducting Cold-Electron 


Bolometers with SIS Tunnel Junctions Technology 

45


5-1 

Lumped Element Kinetic Inductance Detectors for Far Infrared Astronomy 

S. Doyle [1], P. D. Mauskopf [1], P. Ade [1], C. Dunscombe [1], A. Porch [2], J. Naylon [2], S. Withington [3], D. Goldie[3] D. 

Glowacka [3], J. J. A. Baselmans [4], S. J. C. Yates [4], H. F.C. Hoevers [4] 

[1] School of Physics and Astronomy, Cardiff University, Queen’s Buildings, The Parade, Cardiff, CF24 3AA, UK, 

Tel: +44 2920876774, E-mail: simon.doyle@astro.cf.ac.uk 

[2] Cardiff School of Engineering, Cardiff University, Queen’s Buildings, The Parade, Cardiff, CF24 3AA, UK 

[3] SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584CA Utrecht, The Netherlands 

[4] Cavendish Laboratory, Cambridge University, J. J. Thomson avenue, Cambridge, CB3 0HE, UK 

Tel: +44 1223337393, E-mail: s.withington@mrao.cam.ac.uk 

Microwave Kinetic Inductance Detectors (MKIDs) are superconducting microwave resonators 

designed to measure the change in the complex surface impedance of a superconducting film 

upon photon absorption. Photons with energy (hν) greater than the binding energy of a Cooper 

pair (2Δ), if absorbed, will break Cooper pairs in the film causing an increase in quasi-particle 

density along with an increased kinetic inductance. The result of this event is to vary the 

amplitude and frequency of the MKID resonance. Traditionally MKIDs resonators have been 

realized as quarter or half-wave distributed resonators capacitively coupled to a microwave 

feedline. This arrangement requires photons to be coupled into the resonator with the use of 

antennas or quasi-particle traps. In this paper we present a FIR detector based on a lumped 

element geometry - the Lumped Element Kinetic Inductance Detector (LEKID). This device has 

the advantage of acting as a free space absorber as well as being the detecting element and so 

no longer requires an optical coupling element. The LEKID also has the advantage of being far 

smaller than its distributed counterpart making it more suitable for use in large format compact 

arrays. We describe the optimization of lumped element resonators for high coupling efficiency to 

incoming radiation in the wavelength region of 200 μm – 450μm. We also present measurements 

of electrical and optical properties of these devices and the design for a prototype multifrequency 

submm camera using these detectors. 

46


5-2 

1: Title 

Antenna coupled Kinetic Inductance Detectors for space based sub-mm astronomy 

2: authors 

S. J. C. Yates SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584CA Utrecht, The Netherlands 

Tel: +31 30 2538581 Fax: +31 30 2540860, E-mail: S.Yates@sron.nl 

J. J. A. Baselmans SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584CA Utrecht, The Netherlands 

Tel: +31 30 2538580 Fax: +31 30 2540860, E-mail: J.Baselmans@sron.nl 

Rami Barends 

Y.J.Y. Lankwarden 

Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The 


Tel: +31 15 2787163 Fax: +31 30 2540860, R.Barends@TNW.TUDelft.nl 

SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584CA Utrecht, The Netherlands 

Tel: +31 30 2538561 Fax: +31 30 2540860, E-mail: Y.J.Y.Lankwarden@sron.nl 

H. F.C. Hoevers SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584CA Utrecht, The Netherlands 

Tel: +31 30 2535676 Fax: +31 30 2540860, E-mail: H.F.C.Hoevers@sron.nl 

J.R. Gao 

T.M. Klapwijk 

SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584CA Utrecht, The Netherlands 

Tel: +31 30 2538594 Fax: +31 30 2540860, E-mail: J.R.Gao@TNW.TUDelft.nl 

Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The 

Netherlands, Tel: +31 15 2785926 Fax: +31 30 2540860, E-mail T.M.Klapwijk@TNW.TUDelft.nl 

A. Neto TNO Defence, Security and Safety, Den Haag, 2597 AK, The Netherlands 

Tel: +31 703740582, E-mail: andrea.neto@tno.nl 

D. J. Bekers TNO Defence, Security and Safety, Den Haag, 2597 AK, The Netherlands 

Tel: +31 703740960, E-mail: dave.bekers@tno.nl 

G. Gerini TNO Defence, Security and Safety, Den Haag, 2597 AK, The Netherlands 

Tel: +31 703740581, E-mail: giampiero.gerini@tno.nl 

S. Doyle School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, CF24 3AA, UK 

Tel: +44 2920876774, E-mail: simon.doyle@astro.cf.ac.uk 

P. D. Mauskopf School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, CF24 3AA, UK 

Tel: +44 2930876170, E-mail: philip.mauskopf@astro.cf.ac.uk 

P. Ade School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, CF24 3AA, UK 

Tel: +44 2920874643, E-mail: peter.ade@astro.cf.ac.uk 

3: Abstract 

To achieve background limited detection, future space missions in the far infrared and sub-mm 

radiation bands will require large arrays (>1000 pixels) of very sensitive detectors. A typical 

requirement for the noise equivalent power is 10^-19 W/Hz^0.5 for a Fourier Transform 

Spectrometer, which is 100 to 1000 times more sensitive than the state of the art such as on 

HERSCHEL. Such low NEP is a significant technical challenge, both to achieve for the detectors 

and to demonstrate in the laboratory. Kinetic inductance detectors can theoretically achieve this 

performance and have significant advantages over other types of detectors, for example are well 

adapted to frequency domain multiplexing. We present antenna coupled kinetic inductance 

detectors, showing the loaded optical NEP measured with a well controlled narrow band black 

body radiation source. We will also discuss the optimization route required to reach the 

requirements for future missions, including the optical testing requirements. 

47


Antenna-coupled Microwave Kinetic Inductance 

detectors (MKIDs) for mm and submm imaging 

arrays. 

5-3 

A. Vayonakis, J. Schlaerth, S. Kumar, J.-S. Gao, P. Day, B. Mazin, M. 

Ferry, O. Noroozian, J. Glenn, S. Golwala, H. LeDuc, J. Zmuidzinas 

We present results from completely lithographic antenna-coupled Microwave Kinetic 

Inductance detectors (MKIDs). MKIDs are superconducting resonators with resonant 

frequency and quality-factor which are highly sensitive to changes in the density of the 

quasiparticle population which occurs when photons above the superconducting gap 

energy are absorbed. The resonators are coupled to submm light through on-chip phasedarray 

slot antennas. Each planar antenna consists of an array of N long slots which are 

fed along their length at M points. The resulting N*M feed points are combined in-phase 

using a binary summing tree made of low-loss superconducting microstrip lines. Due to 

its large size, the resulting planar antenna produces a narrow beam pattern and can 

therefore be used without additional optical coupling elements such as feedhorns or 

substrate lenses. The output of the antenna is a single superconducting thin-film 

microstrip line which can be efficiently coupled to one (or more) kinetic inductance 

coplanar waveguide resonators to produce a single (or multi-color) pixel in an imaging 

focal plane array, using in-line lumped element lithographic band-pass filters. Such 

highly integrated architectures can be easily fabricated on a single substrate, and many 

detectors can be frequency multiplexed through coupling to a single feedline. Microwave 

readout provides a lot of bandwidth per detector, allowing a large number of pixels to be 

read using a single cryogenic microwave amplifier and warm readout electronics. 

We show results from a demonstration camera (DemoCam) using MKIDs. This camera 

features 16 planar antennas on its focal plane, each feeding two MKID resonators through 

in-line bandpass filters with bands centered at 240 GHz and 350 GHz. 

48


5-4 

Contribution of dielectrics to frequency and noise of NbTiN 

superconducting resonators 

R. Barends 1 , H. L Hortensius 1 , T. Zijlstra 1 , J. J. A. Baselmans 2 , S. J. C. Yates 2 , 

J. R. Gao 1,2 , and T. M. Klapwijk 1 

1 Kavli Institute of NanoScience, Faculty of Applied Sciences, Delft University of 

Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands 

2 SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, 

The Netherlands 

The low temperature microwave properties of superconducting resonators for kinetic 

inductance photon detectors [1] and quantum computation [2] are attracting increased 

attention. At low temperatures both a significant excess frequency noise and deviations in 

the resonance frequency from Mattis-Bardeen theory have been found. It has been 

suggested that these anomalies are caused by dipole two-level systems residing in 

dielectric layers near surfaces, which interact with the high frequency electric fields in the 

resonator [3-4]. In order to identify to what extent two-level systems in dielectrics affect 

the microwave properties of superconducting films we study NbTiN resonators with a 10, 

40 or 160 nm thick SiO2 covering layer. We find that the resonance frequency of bare 

NbTiN resonators, unlike Nb, Ta and Al resonators, closely follows Mattis-Bardeen 

theory down to 350 mK. We demonstrate that deviations in the resonance frequency can 

be generated by covering the resonators with a thin amorphous SiO2 layer, and that these 

deviations scale with the layer thickness. In addition, we find that the frequency noise is 

strongly increased as soon as a SiO2 layer is present, but is, counter-intuitively, 

independent of the layer thickness. These observations show that the physical 

mechanisms causing the excess frequency noise are different from those responsible for 

the deviations in the resonance frequency. 

[1] P. K. Day et al., Nature 425, 817 (2003). 

[2] A. Wallraff et al., Nature 431, 162 (2004). 

[3] J. Gao et al., Appl. Phys. Lett. 90, 102507 (2007). 

[4] J. Gao et al., arXiv:0802.4457. 

49


5-5 

Microstrip-coupled TES bolometers for CLOVER 

M.D. Audley, D. Glowacka, D.J. Goldie, V.N. Tsaneva, S. Withington (Cambridge) 

P.K. Grimes, C. North, G. Yassin (Oxford) 

L. Piccirillo, G. Pisano (Manchester) 

P.A.R. Ade, P. Mauskopf, R.V. Sudiwala, J. Zhang (Cardiff) 

K.D. Irwin (NIST) 

M. Halpern, E. Battistelli (UBC) 

The CLOVER observatory aims to detect the signature of gravitational waves from inflation 

by measuring the B-mode polarization of the cosmic microwave background. We have 

produced microstrip-coupled TES detectors for CLOVER (see Figure 1). The dark NEP of 

these detectors is dominated by the fundamental phonon-noise limit and we have measured 

high optical detection efficiencies in these devices with two completely different RF 

architectures: a finline transition (see Figure 2) and a four-probe OMT (see Figure 3). 

CLOVER consists of two telescopes: one operating at 97 GHz, and one with a combined 

150/220-GHz focal plane. The 220- and 150-GHz detectors use waveguide probes while the 

97-GHz detectors use finline transitions to couple waveguide modes into the microstrip. Each 

detector is fabricated as a single chip to ensure a 100% operational focal plane. The detectors 

are mounted in eight-pixel modules and the focal planes are populated using 12 detector 

modules per detection frequency. Each detector module contains a time-division SQUID 

multiplexer to read out the detectors. Further amplification of the multiplexed signals is 

provided by SQUID series arrays. 

Figure 1 (Left) A microstrip-coupled Mo/Cu TES detector 

fabricated for CLOVER. The TES is at the centre of a 220- 

μm square silicon nitride island which is suspended on four 

nitride legs. The nitride is 0.5 μm thick. Two microstrips 

come in from the right and are terminated by matched 

resistors on the island. 

Figure 2 (Above) Prototype finline-coupled CLOVER 

detector. The chip is about 17 mm long. 

Figure 3 (Left) Four-probe OMT fabricated for CLOVER. The 

probes are suspended on a nitride membrane that lies across a 

circular waveguide ~1.7 mm in diameter. Each probe feeds a 

microstrip that is terminated by a matched resistor on a nitride 

island where the deposited power is measured by a TES. Pairs of 

opposite probes are sensitive to different polarisations. 

We describe the design of the CLOVER detectors and present measurements of the prototype 

detectors' performance showing that they satisfy the requirement of photon-noise limited 

operation on CLOVER. 

50


5-6 

Superconducting transition detectors as power amplifiers for 

cryomultiplexing 

P Helistö, J. Hassel, A. Luukanen*, H. Seppä 

VTT, Sensors, PO Box 1000, 02044 VTT, Finland 

*Millilab, PO Box 1000, 02044 VTT, Finland 

Email: panu.helisto@vtt.fi 

For large scale multiplexing of high-resolution astrophysical radiation detectors, power gain is needed. 

The power gain is normally provided by the readout amplifier, but especially in the case of time division 

multiplexing, power gain by the detector is beneficial. In this paper, we characterise the achievable power 

gain, dynamic range, noise and stability of resistively biased transition detectors. 

Superconducting transition detectors such as X-ray calorimeters or THz bolometers are usually operated in 

voltage biased mode at voltages much below the minimum of the detector I-Vcurve. 1 Such biasing 

provides high current responsivity, low Johnson noise, high stability and good linearity due to the strong 

negative electrothermal feedback (ETF). However, there is no power gain in the detector. This calls for a 

very low noise readout amplifier, typically SQUID, in the case of cryomultiplexing. 

Recently, it was shown that by voltage biasing the detector at the I-Vcurve minimum, a room temperature 

amplifier can read out the signal of transition detectors operated even in the mK range. 2 This is due to 

2 

the effective power gain in the detector near the minimum current bias point: the output noise power r d i n 

of the detector diverges as the differential resistance of the detector r d . 3 Unfortunately, at high frequencies, 

r d is reduced, making the method not optimal for high bandwidth cryomultiplexing. 

Here we demonstrate that by biasing 

the detector through a bias 

resistor, power gain G is obtained, 

the maximum of which 

is equal to the ETF loop gain L 0 . 

The available power gain is limited 

by stability: the dynamic resistance 

of the system has to be 

positive at all frequencies. In 

first experiments we have 

measured power gains of up to 

10-20. In an optimized system, 

we expect to achieve maximum 

power gain up to 50-100, allowing 

multiplexing of up to 100 

detectors in the scheme described 

in Ref 4 . 

gain 

Power 

10 

8 

6 

4 

2 

0 

1.0 

V bias 

R bias 

R(V) 

Theory 

Experiment 100 

P DC,out 

G, T 

P RF,in 

1.2 

I ( A ) 

80 

60 

40 

20 

0 

0 

5 10 15 20 

Bolometer voltage (mV) 

Bolometer voltage (mV) 

Figure 1: Power gain of a superconducting transition bolometer as a function 

of voltage. Squares – experiment, solid line – theory. Insets: Left: 

simplified circuit diagram. Right: bolometer I-V curve. R bias = 9.9 , 

bolometer normal state resistance R N =520 . 

1.4 

Measurement 

Fit 

1.6 

25 

1.8 

1 K. D. Irwin, Appl. Phys. Lett. 66 (1995) 1998–2000. 

2 JS Penttilä, H Sipola, P Helistö and H Seppä, Supercond. Sci. Technol. 19 (2006) 319–322. 

3 P Helistö, JS Penttilä, H Sipola, L Grönberg, F Maibaum, A Luukanen and Heikki Seppä, IEEE Trans. Appl. 

Supercond. 17 (2007) 310 – 313. 

4 A Luukanen et al, this conference. 

51


A Parallel/Series Array of Superconducting Cold-Electron Bolometers 

with SIS´ Tunnel Junctions 

L. Kuzmin 

Chalmers University of Technology, S-41296 Gothenburg, Sweden 

Leonid.kuzmin@mc2.chalmers.se 

5-7 

A novel concept of the parallel/series array of Superconducting Cold-Electron 

Bolometers (SCEB) with Superconductor-Insulator-Weak Superconductor (SIS´) Tunnel 

Junctions has been proposed. The concept was developed for matching the CEB with 

JFET amplifier at conditions of high optical power load. The SCEB array is further 

development of CEB array in current-biased mode [1]. The main difference is in use of a 

weak superconducting absorber and SIS´ junctions instead of a normal absorber and SIN 

junctions. The bias point should be at voltages less than voltage corresponding to a 

difference superconducting gap of electrodes and absorber 1 - 2. This concept gives 

opportunities to fabricate the SCEB array in the same technology as used for the SCEB in 

voltage-biased mode [2]. The SIS´ junctions are fabricated in loop geometry and a critical 

current should be suppressed by a weak magnetic field. 

For combination of effective HF 

operation and low noise properties, 

the current-biased SCEBs are 

connected in parallel for HF signal 

and in series for DC. A signal is 

concentrated from an antenna to the 

absorber through the capacitance of 

the tunnel junctions and through 

additional capacitance for coupling 

of superconducting islands. 

The applications can be considerably extended to higher power load by distributing 

power between N bolometers and decreasing the electron temperature. Due to increased 

responsivity, the photon NEP could be easily achieved at 300 mK for number of 

bolometers in the array more than 4 for wide range of optical power loads. The optimal 

number of bolometers N for power load of 0.5 pW is equal to 8. The concept of the 

SCEB array has been developed for the BOOMERanG balloon telescope and other 

advanced cosmology instruments. 

[1] Leonid Kuzmin, “Array of Cold-Electron Bolometers with SIN Tunnel Junctions for 

Cosmology Experiments”. EUCAS-07; accepted to Journal of Physics: Conference Series 

(JPCS), 2007. 

[2] Leonid Kuzmin, A Superconducting Cold-Electron Bolometer with SIS´ and 

Josephson Tunnel Junctions. LTD-12, accepted to Journal of Low Temperature Physics, 

2007. 

52


Session 6 – THz Receivers / Backends 1 


10:40 – 12:35 

Chair: Jacob Kooi 

10:40 - 11:05 6-1 Innovative technologies for THz Tom Phillips, Caltech 

heterodyne detection (Invited) 

11:05 - 11:20 6-2 2.5-THz heterodyne receiver with Heiko Richter, 

quantum cascade laser and hot electron German Aerospace 

bolometer mixer in a pulse tube cooler Center 

11:20 - 11:35 6-3 CHAMP+: A powerful sub-millimeter Stefan Heyminck, 

heterodyne array 

Max-Planck-Institut für 

Radioastronomie 

11:35 - 11:50 6-4 Large Format Heterodyne Arrays for Christopher Groppi, 

Terahertz Astronomy 


11:50 - 12:05 6-5 APEX Band T2 1.25 – 1.39 THz Denis Meledin, 

Waveguide Balanced HEB Receiver Chalmers University of 

Technology 

12:05 - 12:20 6-6 Instrumentation for Millimetron - a large Wolfgang Wild, 

space antenna for THz astronomy SRON/Univ Groningen 

12:20 - 12:35 6-7 The Next Generation of Fast Fourier Bernd Klein, 

Transform Spectrometer 

Max-Planck-Institut for 

Radioastronomy 

53



Innovative technologies for THz heterodyne detection 

Thomas G. Phillips 

Caltech, Downs 320-47, Pasadena, CA 91106, USA 

The “state-of-the-art” in the field of heterodyne receivers approaches 

(within a factor of a few) the quantum noise limit, for frequencies up to about 

700 GHz, the band-gap of niobium. Such receivers use the SIS structure and 

the physics of photon assisted single quasi-particle tunneling. IF bandwidths 

are as large as 25 GHz. Above 700 GHz various loss mechanisms set in and 

above about 1.4 THz HEB devices are preferred, even though the IF 

bandwidth is usually only a few GHz. 

For the future, at frequencies


6-2 

2.5-THz heterodyne receiver with quantum cascade laser and hot electron bolometer 

mixer in a pulse tube cooler 

H. Richter a , H.-W. Hübers* a , S. G. Pavlov a , A. D. Semenov a , L. Mahler b , A. Tredicucci b , 

H. E. Beere c , D. A. Ritchie c d 

d 

, K. Il’in , M. Siegel 

a German Aerospace Center (DLR), Institute of Planetary Research, 

Rutherfordstr. 2, 12489 Berlin, Germany 

b NEST CNR-INFM and Scuola Normale Superiore, 

Piazza dei Cavalieri 7, 56126 Pisa, Italy 

c Cavendish Laboratory, University of Cambridge, 

Madingley Road, Cambridge CB3 0HE, United Kingdom 

d Institute of Micro- and Nano-Electronic Systems, University of Karlsruhe, 

76187 Karlsruhe, Germany 

The terahertz (THz) portion of the electromagnetic spectrum bears an amazing scientific potential in astronomy. 

High resolution spectroscopy in particular heterodyne spectroscopy of molecular rotational lines and fine 

structure lines of atoms or ions is a powerful tool, which allows obtaining valuable information about the 

observed object such as temperature and dynamical processes as well as density and distribution of particular 

species. Two examples are the HD rotational transition at 2.7 THz, and the OI fine structure line at 4.7 THz. 

These lines are main targets to be observed with GREAT, the German Receiver for Astronomy at Terahertz 

Frequencies, which will be operated on board of SOFIA. 

As part of the receiver development for SOFIA we have developed a liquid cryogen-free heterodyne receiver for 

operation at about 2.5 THz. The front-end of the receiver is integrated in a pulse tube cooler (PTC). It consists of 

a quantum cascade laser (QCL) as local oscillator and a phonon-cooled NbN hot electron bolometric mixer. The 

QCL is mounted on the first stage of the PTC and operates at a temperature of about 50 K while the HEB is 

mounted on the second stage of the PTC (temperature ∼5 K). The performance of the QCL in terms of output 

power, beam profile, and frequency stability as well as the noise temperature of the HEB mixer will be 

presented. The influence of the PTC on the receiver performance as compared to a receiver where the mixer is 

cooled with liquid helium will be discussed. 

55


6-3 

CHAMP+: A powerful sub-millimeter heterodyne array 

S. Heyminck 1) , R. Güsten 1) , B. Klein 1) , C. Kasemann 1) , A. Baryshev 2) , T.M. Klapwijk 3) 

1) Max-Planck-Institute für Radioastronomie, 2) SRON Netherlands Institute for Space Research, 

3) Delft University of Technology 

To make best use of the exceptional weather conditions at Chajnantor we developed 

CHAMP+, a two times seven pixel dual-colour heterodyne array for operation in the 350 

and 450 mu atmospheric windows. 

CHAMP+ uses state-of-the-art SIS-mixers provided by our collaborators at SRON. To 

maximize its performance, optical single-sideband filter are implemented for each of the 

two sub-arrays, and most of the optics is operated cold (20K) to minimize noise 

contributions. 

The instrument can be operated remotely, under full computer control of all components. 

The autocorrelator backend, currently in operation with 2 x 1 GHz of bandwidth for each 

of the 14 heterodyne channels, will be upgraded by a new technologies FFT spectrometer 

array in mid 2008. 

CHAMP+ has been commissioned successfully in late 2007. We will review the 

performance of the instrument “in the field”, and present its characteristics as measured 

on-sky. 

56


6-4 

Large Format Heterodyne Arrays for Terahertz Astronomy 

Christopher Groppi 1 , Christopher Walker 1 , Craig Kulesa 1 , Dathon Golish 1 , Sander 

Weinreb 2,3 , Glenn Jones 3 , Joseph Barden 3 , Hamdi Mani 3 , Jacob Kooi 3 , Art 

Lichtenberger 4 

1: University of Arizona, 2: NASA Jet Propulsion Laboratory, 3: California Institute of 

Technology, 4: University of Virginia 

For future ground, airborne and space based single aperture telescopes, multipixel heterodyne 

imaging arrays are necessary to take full advantage of platform lifetime, and facilitate science 

requiring wide field spectral line imaging. A first generation of heterodyne arrays with ~10 pixels 

has already been constructed, i.e. CHAMP, SMART, HERA, DesertStar, PoleStar and HARP. 

Our group is now constructing Supercam, a 64 pixel heterodyne array for operation in the 

350 GHz atmospheric window. This instrument will realize another order of magnitude increase 

in array pixel count. Several new techniques were used for Supercam to maximize integration and 

modularity. Unlike other SIS array receivers, Supercam is built around 8 pixel linear mixer 

modules, rather than independent mixer blocks. These modules house 8 single ended waveguide 

mixers with SOI substrate SIS devices. Each device is tab bonded to a MMIC based LNA. These 

modules dissipate only 8 mW of heat, while still maintaining 5 K IF noise temperature and 32 dB 

gain. Blind mate IF and DC connectors allow each module to be inserted in or removed from the 

focal plane as a unit. The modules are machined using a state-of-the-art CNC micromilling 

machine acquired specifically for this project. IF signals are processed by 8 channel IF 

downconverter boards, which provide gain, baseband downconversion and IF total power 

monitoring. A real-time FFT spectrometer implemented with high speed ADCs and Xilinx 4 

FPGAs produce spectra of the central 250 MHz of each channel at 0.25 km/s spectral resolution. 

For arrays with an additional order of magnitude increase in pixel count, several 

additional technical problems must be overcome. Kilopixel arrays will require advances in device 

fabrication, cryogenics, micromachining, IF processing and spectrometers. In addition, seemingly 

straightforward receiver systems will require 

new approaches to realize a kilopixel 

heterodyne array with manageable complexity 

and cost. Wire count and 4K heat load must all 

be reduced significantly compared to 

Supercam. IF and DC cabling and 

interconnects may be replaced with 

multiconductor microstrip or stripline ribbon. 

Parallel biasing of LNAs, magnets and even 

SIS devices is feasible if device uniformity is 

good enough. IF processing will require 

further integration, possibly with integrated 

MMIC chips containing all parts of a IF 

downconversion chain. Continued advances in 

FFT spectrometers could allow processing 

many hundreds of gigahertz of IF bandwidth 

for a realizable cost. 

We present results from final 

Supercam receiver integration and testing, and 

concepts for expanding heterodyne arrays to 

kilopixel scales in the future. 

Figure 1: The Supercam receiver system with 

prototype bias electronics and IF processor 

system, and completed 64 channel spectrometer. 

57


6-5 

58


Instrumentation for Millimetron - a large space antenna for 

THz astronomy 

Wolfgang Wild 1,2 , Andrey Baryshev 1,2 , Thijs de Graauw 3 , Nikolay Kardashev 4 , 

Sergey Likhachev 4 ,Gregory Goltsman 4,5 , Valery Koshelets 6 

On behalf of the Millimetron consortium 

1 

SRON Netherlands Institute for Space Research, Groningen, the Netherlands 

2 Kapteyn Astronomical Institute, University of Groningen, the Netherlands 

3 

Leiden Observatory, Leiden, the Netherlands 

4 

Astro Space Center of P.N. Lebedev Physical Institute, Moscow, Russia 

5 

Moscow State Pedagogical University, Moscow, Russia 

6 Institute of Radio Engineering and Electronics, Moscow, Russia 

6-6 


Millimetron is a Russian-led 12m diameter submillimeter and far-infrared space observatory 

which is included in the Space Plan of the Russian Federation and funded for launch after 2015. 

With its large collecting area and state-of-the-art receivers, it will enable unique science and 

allow at least one order of magnitude improvement with respect to the Herschel Space 

Observatory. Millimetron is currently in a conceptual design phase carried out by the Astro Space 

Center in Moscow and SRON Netherlands Institute for Space Research. It will use a passively 

cooled deployable antenna with a high-precision central 3.5m diameter mirror and high-precision 

antenna petals. The antenna is specified for observations up to ~2 THz over the whole 12m 

diameter, and to higher frequencies using the central 3.5m solid mirror. 

Millimetron will be operated in two basic observing modes: as a single-dish observatory, and as 

an element of a ground-space VLBI system. As single-dish, angular resolutions on the order of 3 

to 12 arcsec will be achieved and spectral resolutions of up to 10 6 employing heterodyne 

techniques. As VLBI antenna, the chosen elliptical orbit will provide extremely large VLBI 

baselines (beyond 300,000 km) resulting in micro-arcsec angular resolution. 

The scientific payload will consist of heterodyne and direct detection instruments covering the 

most important sub-/millimeter spectral regions (including some ALMA bands) and will build on 

the Herschel and ALMA heritage. Small arrays of SIS and HEB mixers as well as a far-infrared 

photometer and spectrometer are anticipated. 

The talk will present the overall Millimetron mission concept and status and a possible 

instrumentation suite outlining the needed technology development. 

59


6-7 

The Next Generation of Fast Fourier Transform 

Spectrometer 

B. Klein, I. Kraemer, S. Hochguertel, R. Guesten, A. Bell and K. 

Meyer 

Max-Planck-Institute for Radioastronomy, Bonn, D-53121 Bonn, 

Germany 

We present our second generation of broadband Fast Fourier 

Transform Spectrometers (FFTS), developed for radio astronomical 

applications at the MPIfR. We have developed new analyzer boards, 

making use of the latest version of giga-Hertz analog-to-digital 

converters and the most complex FPGAs commercially available today. 

These state-of-the-art chips have made possible to build a digital 

spectrometer with a monolithic bandwidth of 1.5 GHz and 8192 

frequency channels. To simplify the combination of many analyser 

cards into an array-FFT spectrometer, the novel board includes a 

complete 100 Mbit/s Ethernet interface. Precise time stamping of 

the processed spectra is realized by an on-board GPS/IRIG-B time 

decoder. The compact FFTS board (100 x 160 mm) operates from a 

single 5 Volt source, includes a flexible ADC clock synthesizer, 

and dissipates less than 20 W. Unlike the conventional windowed-FFT 

processing, a more efficient pre-processing algorithm has been 

developed with significantly reduced frequency scallop loss, less 

noise bandwidth expansion, and faster sidelobe fall-off. 

The new spectrometer board has been field-tested at the APEX and we 

present a first 1.5 GHz spectrum as observed in October 2007. 

Finally, we provide an outlook to our on-going developments. 

60


Session 7 – Local Oscillators 


13:45 – 15:20 

Chair: Neal Erickson 

13:45 - 14:10 7-1 Pushing the limits of multiplier chain Imran Mehdi, JPL 

local oscillators (Invited) 

14:10 - 14:35 7-2 Experiences with QCL local oscillators Heinz-Wilhelm Hübers, 

(Invited) 

German Aerospace 

Center 

14:35 - 14:50 7-3 High angular resolution far-field beam Jian-Rong Gao, 

pattern of a surface-plasmon THz SRON / TU Delft 

quantum cascade laser 

14:50 - 15:05 7-4 Integration of Terahertz Quantum Michael Wanke, 

Cascade Lasers with Lithographically Sandia National Labs 

Micromachined Rectangular Waveguides 

15:05 - 15:20 7-5 Phase-locked Local Oscillator for Valery Koshelets, Inst. 

Superconducting Integrated Receiver of Radio Engineering 

and Electronics 

61


7-1 

Invited presentation for ISSTT2008 

Pushing the limits of multiplier based local oscillator chains 

Imran Mehdi, John Ward, Alain Maestrini*, Goutam Chattopadhyay, Erich Schlecht, 

and John Gill 

Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA 91109 

*Université Pierre et Marie Curie-Paris6, LISIF, Paris, France and Observatoire de Paris, LERMA, France 

The successful implementation of robust 

and sufficiently powerful multiplier 

based sources ranging to 1900 GHz for 

the Herschel Space Observatory has now 

made it possible to leverage this 

technology for future missions and 

various other applications. Broadband, 

electronically tunable sources based on 

Schottky diode frequency multipliers 

continue to be an ideal solution for a 

number of proposed applications in the 

THz range. 

Fig. 1. 3D schematic view of the bottom half of the power-combined 260- 

340 GHz frequency tripler based on two mirror-image integrated circuits. 

Fig. 2. Close-up view of the power-combined 260-340 GHz frequency 

tripler showing the two mirror-image GaAs integrated circuits. The E-field 

vectors in the input and output waveguides are indicated by plain arrows. 

The E-fields generated by the two sub-circuits are combined in-phase in 

the output waveguide. 

This talk will survey the current status of 

multiplier based sources and focus on the 

progress that has been made since the 

delivery of HIFI local oscillator chains. 

To improve device yields all chips are 

now fabricated on a membrane regardless 

of operating frequency. While this has 

dramatically increased yields and 

significantly shortened processing times, 

on-chip thermal management has become 

extremely important especially for the 

first stage multipliers. Other objectives of 

the current effort is to extend output 

power and frequency range of these 

sources. A simple in-phase power 

combining scheme that addresses all of 

these concerns has been recently 

demonstrated [1]. A 300 GHz tripler 

block that utilizes two in-phase planar 

chips is shown in Figure 1 and 2. 

Utilizing this simple approach can lead to 

higher output power without sacrificing 

bandwidth. Schemes that utilize even 

more chips in a single block are also 

being considered. Increased output 

power in the drive stages allows one to 

then pump later stages with sufficient 

power. Using this approach can result in 

multiplier based sources working up to 3 

THz with sufficient power to pump single 

pixel receivers. 

[1] Alain Maestrini, John S. Ward, Charlotte 

Tripon-Canseliet, John J. Gill, Choonsup Lee, 

Hamid Javadi, Goutam Chattopadhyay, and Imran 

Mehdi, “In-Phase Power-Combined Frequency 

Triplers at 300 GHz,” to appear in March 2008 

issue of IEEE Microwave and Wireless 

Components Letters. 

62



Experiences with QCL local oscillators 

H.-W. Hübers 


Institute of Planetary Research 


In 2001 the first THz quantum cascade laser (QCL) has been demonstrated. Since then 

rapid progress has been made. Attractive features, which have been demonstrated for 

lasers operating in cw mode are emission between 1.2 THz and 4.9 THz, operation above 

the temperature of liquid nitrogen, output power beyond 100 mW, narrow linewidth of 

less than 10 kHz, and single mode operation by use of a distributed feedback structure. 

These features make QCLs promising devices for use as local oscillator in heterodyne 

receivers such as GREAT on SOFIA or future spaceborne heterodyne receivers. Initial 

experiments with a QCL as local oscillator and a hot electron bolometric mixer have been 

performed in 2005 for the first time. The noise temperature as well as the Allan time were 

the same as measured with a gas laser local oscillator. A major issue is the quality of the 

beam profile. Since the dimensions of the outcoupling facet of a QCL are in the order of 

or even less than the emission wavelength, diffraction degrades the beam profile. 

Nevertheless the output profile of a QCL with a surface plasmon waveguide can be 

transformed into an almost Gaussian profile with appropriate optics. With such a profile 

it was shown that 10 µW power in front of the cryostat window is sufficient for pumping 

the HEB mixer. Also, frequency-locking to a gas laser emission line, Doppler limited 

high resolution molecular spectroscopy, and frequency tuning with an external cavity 

resonator have been demonstrated. In this presentation the state-of-the-art of QCL local 

oscillator development will be reviewed and remaining challenges for implementation in 

a heterodyne receiver will be discussed. 

63


7-3 

High angular resolution far-field beam pattern of a surface-plasmon 

THz quantum cascade laser 

S. Paprotskiy 1.a , X. Gu 1 , J.N. Hovenier 1 , J.R. Gao 1,2 , T.M. Klapwijk 1 , E. E. Orlova 3 , P. 

Khosropanah 2 , S. Barbieri 4 , S. Dhillon 4 , P. Filloux 4 , and C. Sirtori 4 

1 Kavli Institute of NanoScience, Delft University of Technology, Delft, The Netherlands 


3 Institute for Physics of Microstructures, Russian Academy of Sciences, Nishny Novgorod, Russia 

4 Matériaux et Phénomènes Quantiques, Université de Paris 7, Paris Cedex 13, France 

Correspondence: J.R. Gao@tnw.tudelft.nl 

THz quantum cascade lasers (QCLs) are the potential solid-state local oscillators (LO) for 

the frequencies beyond 2 THz because of their frequency coverage, compactness, high 

power efficiency, and narrow linewidth. They have been successfully demonstrated as 

LO in laboratory’s tests. The far-field beam pattern of a THz QCL has been recognized to 

be crucial to couple the power to a mixer. Despite of mW-output power of a QCL, the 

effective power which could be coupled to a hot electron bolometer mixer is still limited 

because of interference fringes in the far-field beam. The latter have been reported in a 

double-metal waveguide QCL [1], surface plasmon waveguide QCL [2], and surface 

plasmon QCL with a DFB structure[3]. 

Surface plasmon waveguide QCLs show more dense interference fringes than 

double metal waveguide QCLs, which makes very challenging to resolve the fingerprint 

of the interference since it requires detection of the radiation intensity with high angular 

resolution. 

In this work, we have developed a new beam pattern setup using a roomtemperature 

pyrodetector and PC controlled two stepper motors. We measured the farfield 

beam patterns of surface plasmon QCLs, which are 217 μm or 157 μm wide, 1500 

mm long, emitted in single mode at 2.84 THz. We discovered that the beams contain two 

types of interference fringes; the type one has the spacing between two fringes that 

decreases with increasing angle, and occurs in the positive space (opposite to the 

substrate of the QCL). Other type has closely, nearly equally spaced rings and happens in 

the negative space. 

The first type of fringes resembles to those found in double metal waveguide 

QCLs[1], which were explained by the interference of radiation from longitudinally 

distributed sources within the laser [4]. However, the spacings between the rings in 

current case are typically a factor of 2 smaller than the model. The second type of rings is 

likely due to the influence of the aperture induced by the metal layer under the QCL 

substrate on radiation interference. 

a On leave from Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Moscow, Russia. 

[1] A. J.L. Adam, I. Kašalynas, J.N. Hovenier, T.O. Klaassen, J.R. Gao, E.E. Orlova, B.S. Williams, S. 

Kumar, Q. Hu, and J. L. Reno, Appl. Phys. Lett. 88, 151105(2006). 

[2] M. Hajenius, P. Khosropanah, J.N. Hovenier, J.R. Gao, T.M. Klapwijk, S. Barbieri, S. Dhillon, P. 

Filloux, C. Sirtori, D.A. Ritchie, and H.E. Beere, Optics Letters ( in press). 

[3] J.N. Hovenier, S. Paprotskiy, J.R. Gao, P. Khosropana, T.M. Klapwijk, L. Ajili, M. A. Ines, and J. 

Faist, Abstract, ISSTT 2007. 

[4] E.E. Orlova, J.N. Hovenier, T.O. Klaassen, I. Kašalynas, A. J.L. Adam, J.R. Gao, T.M. Klapwijk, B.S. 

Williams, S. Kumar, Q. Hu, and J. L. Reno, Phys. Rev. Lett. 96, 173904(2006). 

64


7-4 

Integration of Terahertz Quantum Cascade Lasers with Lithographically 

Micromachined Rectangular Waveguides 

Michael C. Wanke, Christopher Nordquist, Christian L. Arrington, Adam M. Rowen, Albert D. 

Grine, Eric A. Shaner, Mark Lee 

Sandia National Laboratories, Albuquerque, NM, USA 

The quantum cascade laser (QCL) is currently the only solid-state source of coherent THz 

radiation capable of delivering more than 1 mW of average power at frequencies above ~ 2 THz. 

This power level combined with very good intrinsic frequency definition characteristics make 

QCLs an extremely appealing solid-state solution as compact sources for THz transmission and 

illumination and for local oscillators in THz heterodyne receiver systems. However, several 

challenges to the implementation of QCLs as practical THz sources remain. Among these 

challenges are to shape the highly divergent and non-Gaussian output beam patterns observed from 

QCLs into a more useful and predictable beam shape, and to integrate QCLs into the existing, 

broadly used THz technical infrastructure. 

One attractive approach to solving both the beam shaping problem and the integration issue is 

to integrate QCLs into appropriate rectangular waveguides. If the output from a QCL can be 

efficiently coupled into single-mode rectangular waveguide, then the radiation mode structure will 

be known, and the propagation, manipulation, and broadcast of the QCL radiation can then be 

entirely controlled by well-established rectangular waveguide techniques. Because typical QCL 

frequencies are > 2 THz, the dimensions of single-mode rectangular waveguide at these 

wavelengths are on the order of tens of microns. While such small THz waveguides can be made 

by traditional metal machining, this method is typically expensive, slow, and difficult to reconcile 

with the electrical connections needed to support high DC bias currents (order 1 A) required to 

operate a QCL embedded in such waveguide. 

We will report on our efforts to use semiconductor lithographic methods to micromachine 

small, single-mode rectangular waveguide structures compatible with integration of QCLs into a 

waveguide circuit. Such a micromachining approach has the advantage of being amenable to largescale 

production and can be tailored to suit the unique demands of a QCL source. 

We have designed, fabricated, and performed 

preliminary tests on micromachined waveguide 

structures 75 µm wide by 37 µm tall, designed to 

operate single-mode at frequencies around 3 THz. 

These waveguides were fabricated using a 

modified LIGA (German acronym for 

Lithographie, Galvanoformung and Abformung) 

process and were plated with gold. These 

waveguides are coupled to free space via 2- 

dimensional horn flares (see Fig. 1) Initial quasioptical 

transmission measurements at 3.1 THz 

using a molecular gas laser demonstrate that these 

waveguides couple to and guide a THz beam. The 

dominant loss appears to arise from the fact that 

the 2-D horn aperture is much smaller than the 

focused incident beam spot, not from losses in the 

Fig. 1. SEM image of a micromachined 2-D horn 

antenna flare at the end of a rectangular waveguide. 

Horn opening dimension is approximately 200 µm 

wide by 37 µm high. 

waveguide itself. We will also discuss designs, 

simulations, and possibly test results of waveguide structures designed to integrate efficiently with 

metal-metal guided QCL devices. 

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin 

Company, for the United States Department of Energy's National Nuclear Security Administration 

under contract DE-AC04-94AL85000. 

65


7-5 

Phase-locked Local Oscillator for Superconducting Integrated Receiver 

Valery P. Koshelets, Andrey B. Ermakov, Pavel N. Dmitriev, Lyudmila V. Filippenko, 

Nickolay V. Kinev, Oleg S. Kiselev, Alexander S. Sobolev, Mikhail Yu. Torgashin 

Institute of Radio Engineering and Electronics (IREE), Russia 

The Superconducting Integrated Receiver (SIR) comprises in a single chip a planar 

antenna integrated with a superconductor-insulator-superconductor (SIS) mixer, a 

superconducting Flux Flow Oscillator (FFO) acting as Local Oscillator (LO) and a second SIS 

harmonic mixer (HM) for the FFO phase locking. A new generation of the SIR devices with 

improved FFO performance and optimized interface between the FFO and the SIS/HM has been 

developed and comprehensively tested. After optimization of the FFO design the free-running 

linewidth between 7 and 1.5 MHz has been measured in the frequency range 500 – 750 GHz, 

which allows to phase-lock from 50 to 95 % of the emitted FFO power for traditional Nb-AlOx- 

Nb circuits. In order to overcome temperature constraints and extend operation frequency of the 

fully Nb SIR we have developed and studied Nb-AlN-NbN circuits with a gap voltage Vg up to 

3.7 mV and extremely low leak currents (Rj/Rn > 30). Radiation emitted by the FFOs based on 

Nb-AlN-NbN junctions has been studied at frequencies up to 750 GHz. Employment of NbN 

electrodes does not result in noise increase of the FFO biasing current and the linewidth as low 

as 1 MHz was measured at 600 GHz. It allows us to phase lock up to 92 % of the emitted FFO 

power and realize very low phase noise about –90 dBc. In Fig. 1 we present a comparative graph 

of the FFO linewidth for the two circuit types. Abrupt increase of the FFO linewidth at some 

frequencies is caused by Josephson self-coupling (JSC) effect. The JSC (absorption of the 

emitted by an FFO ac radiation by the quasi-particles in the cavity of the long junction) 

considerably modifies FFO properties at the voltages V V JSC =1/3*Vg(V JSC corresponds to 

600 GHz for the Nb-AlN-NbN FFO). It should be mentioned that continuous tuning of the 

frequency is possible for Nb-AlN-NbN FFO due to bending and overlapping of the Fiske steps, 

so that any desirable frequency can be realized. A possibility to phase lock the Nb-AlN-NbN 

FFO at any frequency in the range 350-750 GHz has been experimentally demonstrated. Phase– 

locked SIR operation over frequency range 450 – 700 GHz has been realized, spectral resolution 

below 1 MHz has been confirmed by CW signal measurements. An uncorrected double side 

band (DSB) noise temperature below 150 K has been measured for the SIR with the phaselocked 

FFO and the intermediate frequency bandwidth 4 - 8 GHz. To ensure remote operation of 

the phase-locked SIR several procedures for its automatic computer control have been developed 

and tested. New designs of the FFO intended for further improvement of its parameters are under 

development, results will be presented at the conference. 

(MHz) 

FFO Linewidth 

Free-running 

20 

15 

10 

5 

Nb-AlN-NbN 

Nb-AlOx-Nb 

0 

350 400 450 500 550 600 650 700 750 

FFO Frequency (GHz) 

Fig. 1. Linewidth dependency on 

frequency for two types of the FFO. 

The work was supported in parts by 

the RFBR projects 06-02-17206, 

the ISTC project # 3174, NATO 

SfP Grant 981415, and the Grant 

for Leading Scientific School 

7812.2006.2 

66


Session 8 – Schottky Mixers 


15:45 – 17:00 

Chair: Imran Mehdi 

15:45 - 16:00 8-1 A Schottky-Diode Balanced Mixer Neal Erickson, 

for 1.5 THz 

Univ of Massachusetts 

16:00 - 16:15 8-2 Development and Characterization of Jeffrey Hesler, 

THz Planar Schottky Diode Mixers and VDI / UVA 

Detectors 

16:15 - 16:30 8-3 State-of-the-Art Quasi-Vertical Schottky Oleg Cojocari, 

Diodes for THz-Applications 

ACST GmbH 

16:30 - 16:45 8-4 Schottky Diode Mixers on Gallium Erich Schlecht, JPL 

Arsenide Antimonide? 

16:45 - 17:00 8-5 Development of a 340 GHz Sub- Bertrand Thomas, 

Harmonic Image Rejection Mixer Using Rutherford Appleton 

Planar Schottky Diodes 

Laboratory 

67


8-1 

68


Development and Characterization of THz Planar Schottky Diode 

Mixers and Detectors 

Jeffrey Hesler 1,2 , Haiyong Xu 2 , Alex Brissette 1 and William Bishop 1 

8-2 

This talk will describe the development and characterization of Schottky diode mixers 

and detectors in the frequency band 1.1-1.7 THz. The Schottky diode has a long 

history of use for both heterodyne and direct detection of power at submmwavelengths. 

Schottky diodes have the advantage that they can operate at ambient or 

cryogenic temperature, allow for long integration times, and also have an extremely 

fast response time compared with other detection technologies. The mixers described 

here are single-moded waveguide-based devices without any tuners. Initial 

measurements of the responsivity of a biased Schottky mixer yielded a responsivity of 

100-400 V/W over the range 1.1-1.5 THz. Zero-bias detectors are under development, 

and will be presented at the conference. 

Initial measurements at 1.2 THz of a subharmonically pumped single-ended mixer 

indicated a conversion loss of better than 30 dB with an LO pump power of 0.3 mW 

at 0.6 THz. More detailed characterization of the mixers in a heterodyne mode will be 

presented at the conference, including both fundamentally pumped and high-harmonic 

mixers. 

1 – Virginia Diodes Inc., Charlottesville, VA, USA 

2 – University of Virginia, Charlottesville, VA, USA 

1200 

Responsivity (V/W) 

1000 

800 

600 

400 

200 

0 

1.1 1.2 1.3 1.4 1.5 

Frequency (THz) 

WR-0.65SHM B13 

WR-0.65SHM B5 

Fig. 1. Responsivity measurements for two different designs of a WR-0.65FM 

fundamental mixer. The mixers were biased with a current of 3 uA. 

69


State-of-the-Art Quasi-Vertical Schottky Diodes for THz-Applications 

O. Cojocari (1) , C. Sydlo (1) , I. Oprea (2) ,R. Zimmermann (3) , A. Walber (3) , R. Henneberger (3) 

P. Meissner (2) and H.-L. Hartnagel (2) 

(1) ACST Advanced Compound Semiconductor Technology GmbH, Merckstr. 25, 

64283 Darmstadt, GERMANY. 

(2) Technical University of Darmstadt, Dep of Microwave Engineering, Merckstr. 25, 

64283 Darmstadt, GERMANY. 

(3) RPG Radiometer Physics GmbH - Birkenmaarstraße 10, 53340 Meckenheim, 

GERMANY. 

8-3 

Abstract: 

Schottky is a generic technology, needed not only in space instruments but in practically all 

mm/sub-mm equipment, with the imaging evolving fast to become the primary area of 

application. Commercial applications of Schottky devices have, until very recently, been 

limited to frequencies below 100 GHz. Making available device technologies for higher 

frequencies at a reasonable cost will stimulate the development of existing and the 

appearance of new applications. 

Quasi-vertical diode (QVD) is a Schottky structure suitable for hybrid and monolithic 

integration in THz –circuitry. Low loss in semiconductor substrate and a good heatsink of a 

QVD is ensured by its specific design features as are membrane-substrate and very thin 

mesa enclosed between the Schottky and ohmic contacts, which are situated on its different 

sides. These represent significant advantages over conventional planar diodes for particular 

applications at high frequencies. 

Various diode structures were fabricated and tested. 

Varistor diodes repeatedly show values of the ideality factor η≈1.25 and an unprecedented 

low value of series resistance of R s ≈4Ω for sub-micrometer anodes with junction 

capacitance C 0j ≈2fF. Using the simplest formula for the calculation as f cut-off =1/(2π C 0j R s ) 

these data result in a cut-off-frequency of up to 20THz. Subharmonically-pumped mixers 

were fabricated using waveguide technology and available anti-parallel diode pairs, and 

tested at different frequencies. They show values of the mixer temperature as low as 450K, 

500K, 500K, and 700K (DSB) at frequencies of 150GHz, 183GHz, 220GHz, and 280GHz, 

respectively. These results are well comparable with state-of-the-art mixer performance at 

millimeter waves. 

Varactor diodes exhibit DC-parameters in the ragge of η≈1.08, R s ≈3Ω, C 0j ≈22fF, 

breakdown voltage U bd =13.5V and capacitance modulation factor M= C 0j / C Ubd =4.5. Such 

diodes were mounted in waveguide doubler to 208±10GHz and exhibited up to 30% 

conversion efficiency. Industry experts appreciated these results as extremely encouraging. 

Zero-bias detector diodes exhibit a low video-resistance of below 10kΩ at 0V and a current 

responsivity of above 15A/W for a very small anode area with a junction capacitance of 

below 2fF. The total capacitance of such a diode is around 3fF. These parameters ensure 

high performance of a Zero-Bias Schottky-based detector at frequencies beyond 1THz. 

Technology issues as well as recent measurement results will be presented in the full paper. 

70


8-4 

Schottky Diode Mixers on Gallium Arsenide Antimonide? 

Erich Schlecht and Robert Lin 

Jet Propulsion Laboratory, California Institute of Technology 

Increasing interest in deep space missions using submillimeter and terahertz 

spectrometers increases has recently pushed the development of Schottky mixers in this 

frequency range. Due to the extreme requirements for low mass and power in deep space 

instruments, these mixers are quite attractive because they have good sensitivity, and do 

not need cryogenic cooling for operation. One drawback is that, compared to other 

mixers, they have fairly high LO power requirements, in the range of a milliwatts or 

more. Generally, this is attributed to the fairly high barrier of the usual Schottky contact 

of Au, Pt or Ti on GaAs. 

Fig. 1. Dependence of barrier height on mobility 

for GaAsSb and GaInAs for different thirdelement 

fractions. 

Because of this, it is reasonable to 

explore the use of alternate 

semiconductor systems that have 

lower barriers, and at the same 

time higher mobilities to offset the 

reduced non-linearity of the lower 

barrier materials. Usually, ternary 

compounds have been grown on 

GaAs or InP wafers, and required 

lattice matched mixtures in order to 

prevent development of 

dislocations that would greatly 

reduce mobility. However, the use 

of special techniques such as 

strained superlattice buffer layers 

allows a wider variation of 

materials to be used for devices. In 

this work we will use a harmonic 

balance simulator coupled to our 

recently developed hot-electron 

diode model [1] to analyze 

Schottky mixers fabricated using 

the Gallium Arsenide Antimony 

(GaAsSb) ternary alloy, and compare the results with those fabricated using GaAs and 

Gallium Indium Arsenide for comparison. Figure 1 shows a comparison of barrier height 

versus mobility for GaAsSb and GaInAs for various Antimony and Gallium fraction. The 

results of the simulations will be presented at the conference. 

71


Development of a 340 GHz Sub-Harmonic Image 

Rejection Mixer Using Planar Schottky Diodes 

8-5 

B. Thomas 1 , S. Rea 2 , and D. N. Matheson 1 . 

1 STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK. 

2 EADS-ASTRIUM Ltd, Anchorage Road, Portsmouth, PO3 5PU, UK. 

Space-borne sub-millimeter wave heterodyne instruments can give unique information on 

the distribution of infrared-active molecules in the Earth’s upper troposphere and lower 

stratosphere [1]. In order to resolve fully the emissions from key molecular species in the 

troposphere, it is necessary to separate the receiver sidebands. Previous air-borne limb 

sounding instruments, e.g. MARSCHALS [2], have used frequency selective surfaces in 

the optical path to reject the unwanted sideband. Advances in radio astronomy during the 

past decade have resulted in the development of efficient sideband separating SIS mixers 

for most of the ALMA bands [3]. We present the first extension of this approach to 

semiconductor mixers, reporting on the design and development of a 320 - 360 GHz Sub- 

Harmonic Image Rejection Mixer (SHIRM) that uses planar Schottky diodes. 

The SHIRM architecture features two anti-parallel pairs of planar Schottky diodes flipchip 

mounted onto a single quartz-based microstrip circuit. The RF signal is coupled in 

phase to both Schottky devices, whereas a phase difference of 45 o is introduced between 

the LO signals by using a waveguide quadrature hybrid and stub-loaded phase shifter, all 

integrated inside the SHIRM block. The desired sideband separation is achieved by 

externally recombining the IF outputs using a commercial broadband quadrature hybrid. 

The entire circuit has been optimized using a combination of three-dimensional 

electromagnetic simulations, and linear/non-linear circuit simulations. The SHIRM is 

predicted to have single sideband conversion losses and noise temperatures of 

approximately 10 dB and 2200 K respectively. The calculated sideband image rejection is 

better than 15 dB over the entire 320-360 GHz frequency range. 

Assembly and test of the SHIRM have begun. Measurements will be presented and 

compared with results from a single sideband receiver formed from a 300-350 GHz 

double sideband sub-harmonic Schottky mixer with an integrated IF pre-amplifier and a 

310 GHz frequency selective surface. This receiver has a single sideband noise 

temperature of 5000 K and a side band image rejection of approximately 30 dB [2]. 

This work has been funded by the UK’s DIUS/NERC “Centre for Earth Observation 

Instrumentation”. 

[1] F. von Schéele et al., “The STEAM project”, Proceedings of the 35 th COSPAR 

Science assembly, pp. 2008, Paris, 2004 

[2] B.P. Moyna et al., “MARSCHALS: airborne simulator of a future space 

instrument to observe millimetre-wave limb emission from the upper troposphere 

and lower stratosphere”, 6361-10, Proceedings of the SPIE European Remote 

Sensing Conference, Stockholm, Sept. 2006 

[3] http://www.eso.org/projects/alma 

72


Session 9 – ALMA 


08:30 – 10:25 

Chair: Wolfgang Wild 

08:30 - 08:55 9-1 Submillimeter Interferometers: New Richard Hills, 

standards for future instrumentation ALMA-JAO 

(Invited) 

08:55 - 09:10 9-2 The ALMA Front Ends: an overview Gie Han Tan, ESO 

09:10 - 09:25 9-3 Design and Development of ALMA Shin'ichiro Asayama, 

Band 4 Cartridge Receiver 

NAOJ 

09:25 - 09:40 9-4 ALMA Band 5 (163-211 GHz) Sideband Bhushan Billade, 

Separating Mixer Design 


Technology 

09:40 - 09:55 9-5 Development of ALMA Band 8 Yutaro Sekimoto, 

(385-500 GHz) Cartridge and its NAOJ 

Measurement System 

09:55 - 10:10 9-6 ALMA Band 9 cartridge Andrey Baryshev, 

SRON / University of 

Groningen 

10:10 - 10:25 9-7 Measurement of Emissivity of the Sergey Shitov, 

ALMA Antenna Panel at 840 GHz NAOJ / IREE 

Using NbN-Based Heterodyne SIS 

Receiver 

73


Invited Presentation 9-1 

Submillimeter Interferometers: 

New standards for future instrumentation 

Richard Hills 

Joint ALMA Office, Chile 

The current state of the art, as represented by the systems being developed for ALMA, 

will first be reviewed. This includes extensive use of composite materials on the 

antennas, dual- polarization SIS heterodyne receivers, photonic LO reference systems, 

8GHz IF bandwidth transmitted digitally on optical fibers, and a digital correlator based 

on ASIC’s. 

Various likely lines of development for future Submillimeter Interferometers will then be 

discussed in outline. For antennas, greater use of active control can be expected. 

Receiver systems providing greater bandwidth and multiple beams are becoming 

possible, as are direct photonic LO systems and cost- and power-effective correlators 

based on FPGA’s. 

An alternative line of development would be based on the extending infra-red technology 

to longer wavelengths – e.g. using quasi-optical delay lines and direct detection. The 

question of whether this approach may be advantageous for some astronomical 

applications will be considered. 

74


The ALMA Front Ends: an Overview 

9-2 

Gie Han Tan 

European Organisation for Astronomical Research in the Southern Hemisphere (ESO) 

Garching bei München, Germany 

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a 

partnership between Europe, Japan and North America in cooperation with the Republic of Chile. ALMA is 

funded in Europe by the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), 

in Japan by the National Institutes of Natural Sciences (NINS) in cooperation with the Academia Sinica in 

Taiwan and in North America by the U.S. National Science Foundation (NSF) in cooperation with the National 

Research Council of Canada (NRC). ALMA construction and operations are led on behalf of Europe by ESO, on 

behalf of Japan by the National Astronomical Observatory of Japan (NAOJ) and on behalf of North America by 

the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI). 

The ALMA project is building the ALMA radio astronomy array, consisting of (1) a main array of at least fifty 

12-meter diameter antennas and (2) a compact array of four 12-meter and twelve 7-meter antennas. The 

instrument is to be used for observing astronomical sources in the 31 to 950 GHz frequency range at a 5000 meter 

elevation site in the Atacama Desert of Chile. 

Each ALMA antenna is equipped with a Front End being an assembly of multiple mm and sub-mm wavelength 

receivers and supporting equipment which includes an amplitude calibration device and a dedicated water vapour 

radiometer, operating at 183 GHz, for atmospheric phase calibration. The spectrum from 31 to 950 GHz which is 

observable through the Earth’s atmosphere is divided into ten receiver bands. 

ALMA Band 

Frequency Range (GHz) Responsible Organization 

3 84-116 Herzberg Institute for Astrophysics, Canada 

4 125-163 National Astronomical Observatory of Japan 

5 163-211 Chalmers University – Onsala Space Observatory, Sweden 1 

6 211-275 National Radio Astronomy Observatory, USA 

7 275-373 Institut de Radioastronomie Millimétrique, France 


9 602-720 Netherlands Research School For Astronomy 


1 – Development and pre-production (6 units) funded under European Commission 6 th Framework Programme 

In this presentation the following main topics will be addressed: 

• A brief introduction of the ALMA Front End key technical specifications and the overall receiver 

system design. Given the relatively large amount of front ends to be produced to equip the whole array 

some novel design solutions had to be adopted, e.g. avoiding the use of mechanical tuners – the front 

end is completely electronically tuneable in all respects, including mixer and local oscillator tuning; 

• A summary of how the various activities contributing to the ALMA Front Ends have been organized. In 

this global endeavour more than 10 different organizations, R&D / academic institutes as well as 

industry, are working closely together in developing and manufacturing these state-of-the-art receivers. 

This work has been performed over a period of several years now as a widely distributed effort 

coordinated by ESO in Europe, the NRAO in Northern America, and the NAOJ in East Asia; 

• Current programmatic status of the ALMA Front End sub-project. The design phase of sub-assemblies 

has been completed and for most of these sub-assemblies a pre-production (8 units) phase has been 

successfully accomplished. Full series production has started last year and is currently ramping up, the 

first series production units are expected to be delivered later this year; 

• The latest major technical and programmatic high lights, including the delivery of a first complete 

ALMA Front End to the observatory in Chile. 

This presentation provides an introduction to the various more detailed contributions on ALMA Front End subassemblies 

available at this conference. 

75


Design and Development of ALMA Band 4 Cartridge Receiver 

9-3 

S. Asayama, S. Kawashima, H. Iwashita, T. Takahashi, M. Inata, Y. Obuchi, T. Suzuki, and T. Wada 

Advanced Technology Center and ALMA-J project office, 

National Astronomical Observatory of Japan 

We present the design and development of the ALMA Band 4 cartridge receiver. Band 4 covering 125-163 

GHz is one of the ten bands that will form the ALMA Front End Receiver. There is not enough room inside the 

cartridge to have cold optics as for bands 5 and above, the Band 4 receiver system has ambient temperature 

mirrors (See Fig. 1). A photograph of the Band 4 prototype cartridge is shown in Figure 1. The cartridge 

consists of three stages (at operating temperatures 4, 15, and 110 K) and the base-plate (which acts as a 

vacuum seal) at 300 K, with GFRP 10 spacers between them. The 110 K stage has the LO doublers mounted 

on it and heat sinks for the LO waveguide, coax cables and wiring. The 4 K stage has the corrugated horn, 

orthomode transducer (OMT), 2SB SIS mixers, cryogenic isolators and low noise amplifiers. 

We will give an overview of the Band 4 design and performances such as noise temperature, image rejection, 

phase/amplitude stability, receiver saturation. Receiver beam patterns included warm optics system will be 

presented and compared with physical optics calculations. 

Fig. 1: Band 4 Optics 

Fig. 2: Prototype of Band 4 receiver 

76


ALMA Band 5 (163-211 GHz) Sideband Separating Mixer Design 

9-4 

B. Billade 1 , I. Lapkin 1 , R. Monje 1 , A. Pavolotsky 1 , V. Vassilev 1 , J. Kooi 2 , and V. Belitsky 1 . 

1 Group of Advanced Receiver Development(GARD), Chalmers University of Technology, 

Gothenburg, Sweden. 

2 California Institute of Technology, Pasadena, USA 

Email: bhushan.billade@chalmers.se 

The ALMA interferometric radio telescope is under construction by an international 

consortia consisting of European countries (ESO), USA, Canada, and Japan. The ALMA 

Band 5 will be a dual polarization sideband separating heterodyne receiver covering 163- 

211 GHz with 4 - 8 GHz IF. For each polarization, Band 5 receiver employs sideband 

rejection (2SB) with quadrature layout based on SIS mixers. In order to achieve the 

specified -10dB sideband rejection with reasonable margin, the overall amplitude and phase 

imbalance of the quadrature scheme should be better than -2.5dB and 12 degrees 

respectively. The major contributors to the imbalance are RF and IF hybrids and the 

gain/phase imbalance of the SIS mixers. The amplitude and phase imbalance of SIS mixers 

depends on chip fabrication accuracies, mounting, and mechanical tolerances and can not be 

predicted accurately pushing for strict constrain on the RF and IF hybrids. In order to 

achieve desirable performance, we have performed extensive simulations and optimization 

of all the components of 2SB SIS mixer, including 3D EM modeling using Agilent EMDS, 

and ADS circuit simulator. Our simulations shows that for the given frequency range, the 

RF hybrid can be designed with 0.8 dB amplitude and 3 degree phase imbalance at the best 

case, while the IF hybrid employing an unfolded Lange coupler attains 0.7 dB amplitude 

and 5 degree phase imbalance. For the SIS mixer, we employ MMIC-like approach where 

most of the DSB mixer components are integrated on the same crystal quartz substrate. The 

waveguide-to-microstrip transition is done using an E-probe for both LO and RF. In 

contrast to split block technique, the probe lies perpendicular to the wave direction (backpiece 

configuration) in order to make the mechanical structure more compact; the RF choke 

at the end of the probe provides a virtual ground for the RF signal, and the choke is DC 

grounded to the chassis. The LO injection is done using a microstrip line directional coupler 

with slot-line branches in the ground plane; LO circuitry employs a three stage Chebyshev 

transformer to match it to the LO probe. The isolated port of the LO coupler is terminated 

by floating wideband elliptical termination [1]. The mixer employs two SIS junctions with 

junction area of 3 μm 2 each, in twin junction configuration, followed by a quarter wave 

transformer to couple it to the signal probe. This circuitry provides optimum matching of 

the SIS junctions at RF frequencies though the problem with such architecture is that there 

is no natural cold point to extract the IF. A high-inductance line is therefore used by adding 

a layer of SiO 2 . The biasing network for the SIS junction is placed on the 12K plate, which 

will be connected to a bias-T integrated with the IF hybrid at 4K. 

At the time of the conference we plan to present details of the mixer design and results of 

the first experimental verification of the DSB mixer performance. 

References: 

[1] “High quality micro-strip termination for MMIC and millimeter-wave applications”, 

Raquel Monje, V. Vassilev, A. Pavolotsky, V. Belitsky, IEEE MTT-S international 

microwave symposium, June 2005. 

77


9-5 

Development of ALMA Band 8 (385-500 GHz) 

Cartridge and its Measurement System 

Y. Sekimoto 1 , Y. Iizuka 1 , N. Satou 1 , T. Ito 1 , K. Kumgai 1 , 

M. Kamikura 1 , Y. Serizawa 1 , M. Naruse 1 , and W. L. Shan 2 

1 National Astronomical Observatory of Japan 

2 Purple Mountain Observatory 

We have developed a cartridge-type receiver covering from 385 to 500 GHz for ALMA 

band 8. It receives two orthogonal polarizations and down-converts the sideband 

separated signals to intermediate frequencies (IF) between 4 and 8 GHz. A waveguide 

polarization splitter or ortho-mode transducer (OMT) has been developed, which 

enables the cryogenic optics quite simple. It achieved low loss of ~0.4 dB at 4 K and 

polarization isolation of -25 dB in 385 – 500 GHz [1]. A sideband separating mixer 

consists of two DSB Nb-based SIS mixers and waveguide quadrature coupler which are 

modular to choose balanced combination. An integrated prototype cartridge has low 

noise temperature of < 8 hf/k in SSB and image rejection ratio of > 10 dB in the 80 % of 

ALMA Band 8 frequency. 

We have also developed equipments to test 

both components and integrated receiver 

including submillimeter vector network 

analyzer, near field beam scanner. The 

beam pattern of the cartridge are consistent 

down to -40 dB with physical optical 

calculation [3]. The cross polarization is less 

than -20 dB. The amplitude stability is 

around 3x10 -4 in 1 sec. The phase stability 

is less than 2.0 degree in a time scale from 

0.1 sec to 10 minutes. These results are 

promising for receiver production of the 

Atacama Large Millimeter/submillimeter 

Array (ALMA). 

[1] M. Kamikura et al. 2008 this conference 

[2] M. Kamikura et al. 2006 IJIRMW 

[3] M. Naruse et al. 2008 this conference Figure 4 ALMA Band 8 cartridge 4 K part 

78


ALMA Band 9 cartridge 

9-6 

A. Baryshev 1,2 , F.P. Mena 1,2 , J. Adema 1,2 , R. Hesper 1,2 , B. Jackson 2 , G. Gerlofsma 1,2 , 

M. Bekema 2 , K. Keizer 1 , H. Schaeffer 1 , J. Barkhof 1,2 , C.F.J. Lodewijk 3 , D. Ludkov 3 , 

T. Zijlstra 3 , E. van Zeijl 3 , T.M. Klapwijk 3 , and W. Wild 1,2 

1 

SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen, The 


2 

Kapteyn Astronomical Institute, University of Groningen, Landleven 12, 9747 AD 

Groningen, The Netherlands 

3 

Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of 

Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands 

The Atacama Large Millimeter Array (ALMA) is a collaboration between Europe, North 

America, and Japan to build an aperture synthesis telescope with more than 50 12-m 

antennas at 5000 m altitude in Chile. In its full configuration, ALMA will observe in 10 

bands between 30 and 950 GHz, and will provide astronomers with unprecedented 

sensitivity and spatial resolution at millimetre and sub-millimetre wavelengths. Band 9, 

covering 602-720 GHz, is the highest frequency band in the baseline ALMA project, and 

will thus offer the telescope’s highest spatial resolutions. 

This paper describes the design of the Band 9 receiver cartridges for the Atacama Large 

Millimeter Array (ALMA). These are field-replaceable heterodyne front-ends offering high 

sensitivities, 602-720 GHz frequency coverage, 4-12 GHz IF bandwidth, and high 

quasioptical efficiencies. Because the project will ultimately require up to 64 cartridges to 

fully populate the ALMA array, two key aspects of the design of the Band 9 cartridge have 

been: (1) to take advantage of commercial manufacturing capabilities, and (2) to simplify 

the assembly of the cartridge. 

A first series of eight band 9 receivers has been finished and fully tested. Excellent 

sensitivity over a wide IF band has been achieved, see Fig. 1. This paper will report and 

summarize the measured performance of the first series and discuss possible steps for 

further improvement. 

T noise 

(K) 

300 

250 

200 

150 

Average T noise 

pol. 0 (C1) 

pol. 1 (C1) 

pol. 0 (C2) 

pol. 1 (C2) 

pol. 0 (C3) 

pol. 1 (C3) 

pol. 0 (C4) 

pol. 1 (C4) 

pol. 0 (C5) 

pol. 1 (C5) 

pol. 0 (C6) 

pol. 1 (C6) 

pol. 0 (C7) 

pol. 1 (C7) 

pol. 0 (C8) 

pol. 1 (C8) 

100 

50 

0 

610 620 630 640 650 660 670 680 690 700 710 

F LO 

(GHz) 

Fig. 1, Collection of measured noise temperature for all 16 band 9 SIS mixers mounted in 8 

cartridges. Data is averaged across the 4-12 GHz IF and is not corrected for LO insertion optics. 

79


9-7 

Measurement of Emissivity of the ALMA Antenna Panel at 840 GHz 

Using NbN-Based Heterodyne SIS Receiver 

S. V. Shitov 1,2 , J. Inatani 1 , W.-L. Shan 3 , M. Takeda 4 , A. V. Uvarov 2 and Y. Uzawa 1 

1 National Astronomical Observatory of Japan, Mitaka, Japan 

2 Institute of Radio-Engineering and Electronics, Moscow, Russia 

3 Purple Mountain Observatory, Nanjing, China 

4 Kobe Advanced ICT Research Center (KARC), Kobe, Japan 

The design of the dish for ALMA telescopes is subject to a number of special 

requirements. For example, focusing of the infrared portion of solar radiation must be 

restricted via diffused scattering from the surface of the panel, while RF loss, which cause 

the in-band noise emission, must be below 1%. These are somewhat contradictory 

requirements, since the surface of the antenna must have appropriate roughness (matte 

finish) providing the scattering of IR-radiation. The noise emission of a reflective surface is 

usually measured by a bolometer-based radiometer, which can provide a very high 

sensitivity [1]. Another technique is evaluation of the Q-factor of a resonator formed by the 

reflector under test. However, both techniques have their own drawbacks. A sensitive 

radiometer suffers usually from the low dynamic range while the resonant method assumes 

both precision design and adjustment of a resonator circuit. 

We tested ALMA Band-10 heterodyne SIS receiver as an antenna switching 

radiometer with 8 GHz instantaneous bandwidth (DSB receiver, IF band 4-8 GHz). The 

receiver is mounted within a vacuum 4-K cryostat and contains one of the experimental 

waveguide-type SIS mixers. The particular Band-10 SIS mixer employed the resonant type 

junction made of epitaxial NbN/AlN/NbN trilayer [2]. The noise temperature of the receiver 

referred to the antenna load is about 560 K (DSB) or about 330 K, if corrected for 25-µm 

Kapton beamsplitter. The receiver’s antenna switch is balanced to terminate the receiver 

input to a common 80-K absorber via two different paths. In this configuration, the 

emissivity of the surface is detected via the imbalance of the antenna switch occurring when 

the sample-under-test is inserted to produce the extra reflection. Since the large dynamic 

range of the receiver, the response can be calibrated with traditional 300-K and 80-K 

antenna loads. 

The value of (0.25±0.10)% has been measured for the sample of the antenna panel. 

To confirm both the measured value and the general feasibility of the method, samples 

made of phosphor bronze and stainless steel are measured using the same technique. The 

values of (0.30±0.10)% and (1.10±0.10)% are obtained for these samples correspondingly 

that is consistent with data obtained with bolometer radiometer [1]. The accuracy of the 

described technique will be discussed, that includes the effects of non-thermostatic 

environment. 

[1] A. E. Lange, S. Hayakawa, T. Matsumoto, H. Matsuo, H. Murakami, P. L. Richards, and 

S. Sato, "Rocket-borne submillimeter radiometer," Appl. Opt. 26, p. 401 (1987) 

[2] Y. Uzawa, Z. Wang; A. Saito, A. Kawakami, M. Takeda, “Development of a waveguide 

NbN-based SIS mixer in the 900-GHz band,” IEEE Transactions on Applied 

Superconductivity, Vol. 13, Issue 2, June 2003, pp. 692-695. 

80


Session 10 – THz Receivers / Backends 2 


10:50 – 12:50 

Chair: Victor Belitsky 

10:50 - 11:05 10-1 Spectrometers for (sub)mm radiometer Anders Emrich, 

applications 

Omnisys 

11:05 - 11:20 10-2 Flight configuration of the TELIS Pavel Yagoubov, 

Instrument 


11:20 - 11:35 10-3 Performance Characterization of GISMO, Johannes Staguhn, 

a 2 Millimeter TES Bolometer Camera NASA/GSFC & 

used at the IRAM 30 m Telescope University of Maryland 

11:35 - 11:50 10-4 350GHz band Sideband Separating Hirofumi Inoue, 

Receiver for ASTE 


11:50 - 12:05 10-5 Development of a Waveguide-Type Taku Nakajima, 

Dual-polarization Sideband-Separating Osaka Prefecture 

SIS Receiver System in 100 GHz Band University 

for the NRO 45-m Radio Telescope 

12:05 - 12:20 10-6 A modular 16-pixel terahertz imager Mikko Leivo, VTT 

system applying superconducting 

microbolometers and room temperature 

read-out electronics 

12:20 - 12:35 10-7 A novel heterodyne interferometer for Paul Grimes, 

millimetre and submillimetre astronomy Oxford University 

12:35 - 12:50 10-8 A 600 GHz Imaging Radar for Goutam Chattopadhyay, 

Contraband Detection 

JPL/Caltech 

81


10-1 

Spectrometers for (sub)mm radiometer applications 

A. Emrich, M. Krus, J. Riesbeck, S. Andersson, Magnus Hjort 

Omnisys Instruments AB, Gruvgatan 8, 421 30 Göteborg, Sweden 

ABSTRACT 

The FFT spectrometer and autocorrelation spectrometers are two of 5 types of spectrometers being considered for space 

based (sub)millimetre heterodyne systems. The advantages of the digital autocorrelation and FFT spectrometers 

compared to Chirp Transform, Acousto Optical and Filterbank spectrometers are; stability, compactness, high reliability 

and variability in bandwidth and resolution. FFT spectrometers based on the latest generation of FPGA devices now 

promise a cost effective alternative for low to medium bandwidth applications with high resolution requirements. 

Omnisys has an FFT spectrometer design optimized 

for ground based applications. It follows the single 

Eurocard standard size and provides up to 2 GHz 

bandwidth and 1-4 inputs. With four inputs, the 

maximum processed bandwidth is 500 MHz. 

Configurations with polyphase filtering, 

polarization processing and variable resolution over 

the processed band have also been tested. 

Omnisys FFT board provides 2 GHz processed 

bandwidth with a power budget of less than 20W. 

The next generation will provide 4 GHz of 

bandwidth per board. 

For the SuperCAM imaging system, 16 boards will 

be used in two single height 19” crates to provide 64 

spectrometers. It could be upgraded to provide 64 

times 1 GHz by simply adding two crates. Test 

results will be shown in the conference. 

These can be housed in one single height 19” crate 

together with IF systems and embedded computers providing flexible interfaces to front-ends as well as flexible 

interfaces for switch synchronization, data readout and other forms of control. The default interface is 100 MBit/s 

Ethernet. This is a breakthrough for future imaging applications as we can provide spectrometers for 5 kEuro each (in 

reasonable volume). 

Omnisys has designed and implemented several generations of autocorrelation chip sets and spectrometers. This range 

from the ODIN satellite spectrometers now in LEO to our current 8 GHz single chip spectrometer. The ODIN chip set 

was a breakthrough at the time (1998). The power consumption was lowered by a factor of 50 

HIFAS, Omnisys fifth generation autocorrelation spectrometer ASIC is being developed. 

It is a full-custom design with over two million transistors, designed for IBM’s 180 nm 

SiGe Bi-CMOS process. Unlike earlier generations, it contains both the bipolar 3-level 

(“1.5-bit”) A/D converter and the CMOS correlator on the same chip. Thereby, the 

sensitive high-speed digital interface between the two parts gets integrated on the chip. 

The chip supports as input either a complex I/Q input 

signal pair, measuring its spectrum from –fclk/2 to 

+fclk/2 or a single baseband signal sampled on both 

clock edges, measuring from 0 to fclk. This choice 

gives flexibility for the system level design. 

The first batch of the chip was produced in 2007. Unfortunately it turned out to have 

a logic bug that makes it necessary to do a re-run. A second revision of the chip is 

being designed at the time of this writing, and tape-out is planned for early 2008. 

Despite these initial problems with the chip, most of the chip’s functions have been 

tested and shown to work. The analog parts work in both of the two input modes 

with up to 8 GHz sample clock. 

The goal is to reach a bandwidth of 8 GHz, a resolution of 1024 channels, and a power consumption of 3-4 W. When 

finished, this chip will set a new world record in autocorrelator performance, and open for new possibilities in 

radiometry on both space and ground. 

82


10-2 

Flight configuration of the TELIS instrument. 

Gert de Lange, Pavel Yagoubov, Hans Golstein, Leo de Jong, Arno de Lange, Bart van 

Kuik, Ed de Vries, Johannes Dercksen, Ruud Hoogeveen 

SRON Netherlands Institute for Space Research, the Netherlands 

Valery Koshelets, Andrey Ermakov 

Institute of Radio Engineering and Electronics (IREE), Moscow, Russia 

The TELIS (Terahertz and sub-millimeter limb sounder) instrument is a three-channel 

heterodyne receiver developed for observations of the stratosphere. TELIS will fly together 

with the MIPAS-B2 instrument on a balloon platform of the Institute for Meteorology and 

Climate Research of the University of Karlsruhe (IMK, Germany). TELIS will observe both in 

the sub-millimeter range (480-650 GHz) and at 1.8 THz, while MIPAS-B2 observes tracegases 

in the thermal infrared. Results will be used to refine and constrain numerical 

chemical transport models. 

The SRON contribution to TELIS is the 500-650 GHz Superconducting Integrated Receiver 

(SIR) channel. This is a unique superconducting on-chip heterodyne receiver, consisting of 

a double dipole antenna, a SIS mixer, a flux-flow Local Oscillator, and a superconducting 

harmonic mixer used for phase locking of the LO-signal. The bandwidth of the Digital 

Autocorrelator IF-backend of the SIR-receiver channel is 2 GHz, centered at 6 GHz. The 

lowest noise temperature of the receiver is 120 K DSB, meaured over the full IF bandwidth. 

Although the concept of an integrated receiver has been explored for some years, the actual 

use of such a receiver for scientific observations so far has not been demonstrated. The first 

flight campaign with TELIS/MIPAS is scheduled for May 2008 from Teresina (Brazil). 

In the presentation we will discuss the design, performance and operation of the SIRchannel. 

83


Performance Characterization of GISMO, a 2 Millimeter TES 

Bolometer Camera used at the IRAM 30 m Telescope 

10-3 

Johannes Staguhn 1,2 , Christine Allen 1 , Dominic Benford 1 , Stephen Maher 1 , Elmer Sharp 1 , 

Troy Ames 1 , Rick Arendt 1 , David Chuss 1 , Eli Dwek 1 , Dale Fixsen 1,2 , Stephen Maher 1,5 , 

Catherine Marx 1 , Tim Miller 1 , S. Harvey Moseley 1 , Santiago Navarro 3 , Eva Schinnerer 4 , 

Albrecht Sievers 4 , George Voellmer 1 ,Fabian Walter 4 , Edward Wollack 1 

1 NASA/ Goddard Space Flight Center, 2 University of Maryland, 3 IRAM Spain, 4 MPIA 

Heidelberg, 5 SSAI Lanham 


We have developed key technologies to enable highly versatile, kilopixel, infrared through 

millimeter wavelength bolometer arrays. The Backshort-Under-Grid (BUG) array consists 

of three components: 1) a transition-edge-sensor (TES) based bolometer array with 

background-limited sensitivity and high filling factor, 2) a quarter-wave reflective 

backshort grid providing high optical efficiency, and 3) a superconducting bump-bonded 

large format Superconducting Quantum Interference Device (SQUID) multiplexer readout. 

In November of 2007 we demonstrated a monolithic 8x16 array with 2 mm-pitch detectors 

in the field using our 2 mm wavelength imager GISMO (Goddard IRAM Superconducting 

2 Millimeter Observer) at the IRAM 30 m telescope in Spain for astronomical 

observations. The 2 mm spectral range provides a unique terrestrial window enabling 

ground-based observations of the earliest active dusty galaxies in the universe and thereby 

allowing a better constraint on the star formation rate in these objects. I will present early 

results from our observing run with the first fielded BUG bolometer array. 

84


350GHz Sideband Separating Receiver for ASTE 

10-4 

Hirofumi INOUE 1 , Kazuyuki MURAOKA 1 , Takeshi SAKAI 2 , Akira ENDO 1, 2 , Kotaro 

KOHNO 1 , Shin’ichiro ASAYAMA 2 , Takashi NOGUCHI 2 , Hideo OGAWA 3 

1. Institute of Astronomy, The University of Tokyo 

2. National Astronomical Observatory of Japan 

3. Department of Physical Science, Graduate School of Science, Osaka Prefecture University 

(Abstract) 

We have developed a 350GHz sideband separating (2SB) receiver “CATS345 

(CArtridge Type Sideband separating receiver)” for the Atacama Sub-millimeter Telescope 

Experiment (ASTE), a project for observations of the southern sky at sub-millimeter 

wavelengths with a 10m telescope in Atacama, Chile. The LO frequency (fLO) of this receiver 

is from 330 to 360GHz and the IF band is from 4 to 8GHz. In laboratory, the receiver noise 

temperature (TRX) was typically 200K(SSB) for fLO=330-350GHz and image rejection ratio 

(IRR) was typically 10dB for fLO=330-360GHz. 

An automatic data acquisition system using LabVIEW and GPIB has been 

developed. This system allows one to sweep the entire (V1, V2, PLO) space semiautomatically, 

providing insight towards the general behavior of the receiver performance 

according to external tuning conditions. 

We installed this receiver on the ASTE telescope with a new 4GHz backend in 

October 2007. The system noise temperature on site was 200K(SSB) for fLO=335-350GHz, 

which is half of that of the previous DSB receiver. So the observation time is reduced to 1/4. 

The Allan time is about 10 sec in both sidebands. 

This is the first sideband separating receiver in the 350GHz band that can be used 

commonly. 

Figure 1. CATS345 

Figure 2. System noise temperature 

(SSB) at ASTE site 

85


10-5 

Development of a Waveguide-Type Dual-polarization Sideband-Separating 

SIS Receiver System in 100 GHz Band for the NRO 45-m Radio Telescope 

Taku Nakajima 1 Masayuki Kawamura 1 Kimihiro Kimura 1 Yoshinori Yonekura 1 Hideo Ogawa 1 

Takeshi Sakai 2 Nario Kuno 2 Masato Tsuboi 3 Shin’ichiro Asayama 4 Takashi Noguchi 4 Ryohei Kawabe 2 

1. Department of Physical Science, Graduate School of Science, Osaka Prefecture University 

2. Nobeyama Radio Observatory, National Astronomical Observatory of Japan 

3. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency 

4. Advanced Technology Center, National Astronomical Observatory of Japan 

We have developed a waveguide-type dual-polarization 

sideband-separating SIS receiver system in 100 GHz 

band for the 45-m radio telescope at the Nobeyama 

Radio Observatory, Japan. The new receiver uses a 

waveguide-type Ortho-Mode Transducer (OMT) and 

two Sideband-Separating (2SB) SIS mixers (Fig.1). The 

SSB receiver noise temperature with 4.0-8.0 GHz IF, 

including the noise contribution from the vacuum 

window, the feed horn, and the IF amplifier chain, are 

measured to be lower than 100 K over the RF range of 

75-120 GHz, and the minimum value of ~ 45 K is achieved at around 95 GHz. The mean value and 

standard deviation between RF frequency range of 75-106 GHz in the LSB and 79-120 GHz in the USB 

are 68 13 K and 66 9 K, respectively (Fig.2 (a)). The measured IRR was better than 10 dB over the RF 

range of 80-123GHz. The mean value between RF frequency range of 80-111 GHz in the LSB and 84-123 

GHz in the USB are 20 dB and 19 dB, respectively (Fig.2 (b)). The new receiver system has been 

installed in the telescope, and we successfully detected the molecular lines over the RF range of 80-116 

GHz toward Orion KL in 2007 December. These are the first astronomical observations with the 

waveguide-type dual-polarization sideband-separating SIS receiver system in the 100 GHz band. A 

molecular line survey using this receiver system has already begun. 

200 

40 

150 

USB 

LSB 

30 

USB 

LSB 

100 

20 

50 

10 

0 

70 80 90 100 110 120 130 

RF Frequency [GHz] 

0 

70 80 90 100 110 120 130 

RF Frequency [GHz] 

86


A modular 16-pixel terahertz imager system applying superconducting 

microbolometers and room temperature read-out electronics 

M. Leivo 1 , P. Helistö 1 , A. Luukanen 2 , J.S. Penttilä 3 , T. Perälä 1 , 

A. Rautiainen 1 , H. Toivanen 1 , C.R. Dietlein 4 , and E.N. Grossman 4 

1 

VTT, Sensors, Espoo, Finland 

2 

Millimeter-wave Laboratory of Finland, Espoo, Finland 

3 

Aivon Oy, Espoo, Finland 

4 

National Institute of Standards and Technology, 

Optoelectronics Division, Boulder, CO, USA 

10-6 

Superconducting bolometers have long been used as the "work horse" technology for 

terahertz astrophysics. In this paper we describe a system developed for stand-off imaging of 

concealed weapons and explosives. The system utilizes an array of NbN antenna-coupled 

vacuum-bridge microbolometers as detectors. The detectors are modular, with 8 pixels 

incorporated within a single module. The modules are mounted onto the 2 nd cooling stage of a 

commercial cryogen-free pulse tube refrigerator with a base temperature of ca. 4 K. The 

readout of the sensors is carried out with an innovative room-temperature feedback 

preamplifier that can achieve bolometer noise limited performance when operated at the 

"inflexion point" of the voltage-biased bolometer. 

In the paper we will describe the overall architecture of the modular system, describe the 

electrical and optical performance characteristics of the system, and show passive imagery of 

test objects acquired in the 200 GHz to 1 THz band. The system is a precursor for a video-rate 

imaging THz camera, which will be briefly discussed. 

Fig. 1. Left) Overall setup of a 16-pixel THz imager system. Center) Two bolometer modules attached 

to pulse tube cold finger. Right) Micrograph of an antenna-coupled vacuum-bridge microbolometer 

array. 

87


A novel heterodyne interferometer for millimetre and submillimetre astronomy 

10-7 

Paul K. Grimes, Christian M. Holler, Michael E. Jones, Oliver G. King, Jamie Leech, Angela C. Taylor, 

Ghassan Yassin 

Astrophysics, Oxford University, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH, UK. 

pxg@astro.ox.ac.uk 

We describe a novel heterodyne interferometer currently under construction at Oxford, funded by the 

Royal Society's Paul Instrument Fund to investigate the Sunyaev-Zeldovich (S-Z) effect at 230 GHz. 

An important feature of this instrument is that it employs several pioneering technologies of importance 

to mm and sub-mm wave heterodyne interferometry. The instrument is a 190-260 GHz single-baseline 

interferometer employing SIS mixers, very wide bandwidth low-noise IF amplifiers, and a wide-band 

analogue correlator. The unique feature of this instrument is its exceptionally high brightness sensitivity 

on large angular scales combined with moderate frequency resolution. This novel, portable instrument 

may be considered as a first demonstration for a future large format international S-Z project. We expect 

the instrument to be commissioned in 2010 and astronomical observations will be carried out at the 

Chajnantor Observatory, Chile, close to the core ALMA site. 

The instrument is a single baseline tracking interferometer with 0.4m diameter offset parabolic primary 

mirrors and a 0.5m baseline. The antennas feed two SIS mixers contained in a single closed cycle 

cryostat and driven by photonic local oscillator using a single laser source. The interferometer will be 

phase switched by introducing phase shifts in the LO signals fed to each mixer. 

The SIS mixers are single-chip balanced mixers using back-to-back finline geometry. The mixers have 

been designed for extremely wide IF band, up to 2-20 GHz, and feed high performance cryogenic 

HEMT amplifiers developed by Sander Weinreb. Some major RF modifications need to be done to the 

standard finline mixer design to allow for very wide IF band operation, including the use of microstrip 

and capacitor RF bandpass filters between the finline feed and the SIS junction, and the use of low 

parasitic microstrip RF chokes, tuning and IF matching circuits. 

We will demonstrate the extremely high brightness sensitivity of this technology, by measuring the zerocrossing 

frequency of the Sunyaev-Zeldovich (S-Z) effect in a few of the brightest galaxy clusters. The 

S-Z effect is the distortion of the spectrum of the CMB due to its passage through a cluster of galaxies; 

the effect is negative at low frequencies and positive at high frequencies, with the null close to 220 GHz. 

The exact null frequency varies depending on the temperature of the cluster gas and is approximated by 

(217+0.45(T/keV) GHz where T is the cluster gas temperature. 

Our instrument will initially observe two 10-GHz bands spaced 8 GHz either side of 217 GHz, each split 

into eight sub-bands. We should be able to measure the null frequency for a few bright clusters with a 

few nights of observing each. This unique measurement will be a convincing demonstration of the 

capabilities of the new technology. As well as observing clusters, to verify the performance of the 

instrument we will carry out extensive observations of bright calibrator sources, and of signals from the 

atmosphere. The wide spacing and frequency resolution of the bands, plus the fact that we will measure 

both the total power from each antenna and the correlated power between them, will be ideal for 

characterising the contribution to observed fluctuations from wet and dry components of the atmosphere. 

A future ground-based instrument based on these same principles, with more baselines and hence greater 

sensitivity, could obtain cluster temperatures faster than the best current X-ray satellite observatories, at 

a tiny fraction of the cost. Other applications of the same techniques could include highly sensitive 

pseudo-correlation polarimetry (for example for a future CMB satellite observatory), or spectroscopy of 

atmospheric emission lines in limb-sounding applications. All of the technology developed for this 

instrument has applications for instrumentation throughout the mm and sub-mm wave region and can 

easily be extended to the THz spectrum. 

88


10-8 

A 600 GHz Imaging Radar for Contraband Detection 

Goutam Chattopadhyay, Ken B. Cooper, Robert Dengler, Tomas E. Bryllert, 

Erich Schlecht, Anders Skalare, Imran Mehdi, and Peter H. Siegel 


4800 Oak Grove Drive, Pasadena, CA 91109, USA. 

ABSTRACT 

We have developed and demonstrated 3D imaging for contraband detection using a 

submillimeter-wave frequency modulated continuous wave (FMCW) radar with a fast 

microwave chirp and phase coherent detection. The technique provides an important 

advantage over more traditional CW RF imaging because of the ability to time-gate the 

return signals. This can be used to discern specific objects by greatly reducing clutter 

from unwanted targets or specular reflections. The prototype system uses a 590 GHz RF 

signal with a 28.8 GHz chirp producing a 1.2 MHz/usec sweep yielding a range 

resolution of approximately 1 cm or less. Lateral resolution on the scene is set by a 40cm 

diameter reflector producing approximately 0.5cm at 4m distance. The RF transmit 

power (generated by a W-band power amplifier and an in-house frequency multiplier 

chain) is less than 0.5 mW but when coupled with a heterodyne downconverter (in-house 

developed fundamental balanced Schottky diode mixer, 4000K DSB noise temperature) 

yields a measured dynamic range of more than 70dB. A more compact and higher 

resolution system is currently under construction and will employ a commercial 30 GHz 

microwave chirp for sub-cm range resolution and a higher power transmitter, 

dramatically increasing resolution and dynamic range. This paper will describe the design 

and implementation of the radar with some results we have obtained on test targets at 4 m 

and 25 m. 

The research described herein was carried out at the Jet Propulsion Laboratory, California 

Institute of Technology, Pasadena, California, USA, under contract with National 

Aeronautics and Space Administration. 

Fig: A 600 GHz radar image of a concealed gun under a shirt at 4 m stand-off distance. The picture on the left shows 

the optical image, the figure in the middle shows radar data range-gated at the front surface, and the image on the right 

shows the radar data range-gated at the back surface. 

89


90


Session 11 – Novel Devices & Measurements 


14:05 – 15:05 

Chair: Paul Richards 

14:05 - 14:20 11-1 Experimental detection of terahertz Sigfrid Yngvesson, 

radiation in bundles of single wall University of Massachusetts 

carbon nanotubes 

14:20 - 14:35 11-2 An Empirical probe to the Operation of Edward Tong, 

SIS Receivers – Revisiting the 

Harvard- Smithsonian 

Technique of Intersecting Lines 

Center for Astrophysics 

14:35 - 14:50 11-3 Short GaAs/AlAs superlattices as THz Dmitry Paveliev, Nizhny 

radiation sources 

Novgorod State University 

14:50 - 15:05 11-4 A new experimental procedure for Christopher Thomas, 

determining the response of bolometric University of Cambridge 

detectors to fields in any state of 

coherence 

91


Experimental detection of terahertz radiation in bundles of single wall carbon 

nanotubes 

K.S. Yngvesson, K. Fu, R. Zannoni, C. Chan, S.H.Adams, J. Nicholson, and E. Polizzi 

Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, MA 01003, USA 

11-1 

We report the experimental detection of 

terahertz radiation at five frequencies from 0.69 

THz to 2.54 THz in devices consisting of bundles 

of carbon nanotubes, containing metallic single 

wall carbon nanotubes (m-SWNTs). The CNTs 

are quasi-optically coupled through a 

lithographically fabricated antenna, and a silicon 

lens. The measured data are consistent with a 

bolometric detection process in the m-SWNTs 

and the devices show promise for operation well 

above 4.2 K. The maximum responsivity at 

present is about 10 V/W but analysis shows how 

this may be increased by two to three orders of 

magnitude in the future. 

Itkis et al. [1] have reported a sensitive 

bolometric Near Infrared detector based on a 

Carbon Nanotube (CNT) film. Microwave 

detection using CNT Schottky barriers, CNT- 

FETs and CNT bundles has been extended to 110 

GHz [2]. The question thus arises whether 

SWNTs could be useful as terahertz detectors, as 

we proposed in [3]. We reported microwave 

detection in single m-SWNTs at a previous 

ISSTT [4]. For the present work we have 

fabricated bundles containing m-SWNT devices 

by the Dielectrophoresis (DEP) method. We 

performed microwave measurements on CNTs 

contacted to CPWs and terahertz measurements 

on CNTs coupled to a log-periodic antenna, the 

latter with an 8 μm gap. The terahertz source was 

a gas laser. Each metallic SWNT tube is assumed 

to be modeled by the equivalent circuit 

introduced and analyzed by P. Burke [5] based 

on which we estimated the average coupling loss 

to be 12 dB. It is significant that the microwave 

measurements indicate a large enough contact 

capacitance that effectively shunts the contact 

resistance at terahertz frequencies. 

Our hypothesis is that the detection process 

at terahertz frequencies is of the bolometric type, 

similar to that in ref. [1], in contrast with the 

diode-like detection mechanism at microwaves 

[4]. To support this hypothesis we have 

measured the temperature-dependence of the 

device resistance. When using this data to predict 

the voltage responsivity as a function of bias 

voltage we find very good agreement. The CNT 

bolometer then effectively is similar to a phononcooled 

HEB, that potentially has a shorter 

thermal time constant than superconducting 

HEBs. 

Ab initio simulations are also being 

performed to model contact and transport effects 

in the CNTs. Preliminary results of these 

simulations have been published in [6]. 

Future work will concentrate on improved 

fabrication and simulation methods for m-SWNT 

devices, optimizing the device coupling, and 

demonstration of heterodyne detection. 

This work was supported by NSF grants ECS- 

0508436 and ECS-0725613. 

References 

[1] M.E. Itkis, F. Borondics, A. Yu and R.C. 

Haddon, Science, 312, 413 (2006). 

[2] M. Tarasov, J. Svensson, L. Kuzmin, and E. 

E. B. Campbell, Appl. Phys. Lett., 90, 163503 

(2007). 

[3] K.S. Yngvesson, Appl. Phys. Lett. 87, 

043503 (2005). 

[4] K.S. Yngvesson et al., 17th ISSTT, Paris, 

France, May 2006. 

[5] P.J. Burke, IEEE Trans. Nano Technol. 1, 

129 (2002). 

[6] D. Zhang and E. Polizzi, J. Comp. 

Electronics, 2007, accepted. 

92


11-2 

An Empirical probe to the Operation of SIS Receivers --- 

Revisiting the Technique of Intersecting Lines 

Edward Tong, Abby Hedden and Ray Blundell 

Harvard-Smithsonian Center for Astrophysics 

60 Garden St., Cambridge, MA 02138, USA 

The technique of intersecting lines [1,2] has been introduced to deduce the part of the 

receiver noise temperature of an SIS receiver, which is invariant with the conversion gain, 

namely the ‘input loss’ of the receiver. We have recently conducted a series of experiments 

with the objective to determine the range of validity of this method. Using SIS receivers 

operating in the 200 and 300 GHz range, the input losses of the receivers operating under a 

variety of conditions have been determined. We have demonstrated that the method of 

intersecting lines is indeed useful in the determination of losses introduced in front of the 

receiver. An alternate formulation of the measurement method will also be presented. This 

alternate approach allows the user to determine the input loss temperature with a higher 

accuracy, and the error of measurement can easily be inferred. 

[1] Blundell, Miller and Gundlach, “Understanding noise of SIS receivers,” Int. J. IR&MM Waves, vol. 13, p.3-14, 

Jan. 1992 

[2] Ke and Feldman, “A technique for accurate noise temperature measurements for the superconducting 

quasiparticle receiver,” Proc. 4 th Int. Symp. Space THz Tech., pp. 33-40, UCLA, March 1993. 

93


11-3 

Short GaAs/AlAs superlattices as THz radiation sources 

D.G. Paveliev, Yu.I. Koschurinov 

Radiophysics Department, Nizhny Novgorod State University, Russia 

V.M. Ustinov, A.E. Zhukov 

Ioffe Physico-Technical Institute,St.Petersburg,Russia 

F. Lewen, C. Endres 

I.Physikalisches Institut, Universität zu Köln, Germany 

A.M. Baryshev 

SRON Netherlands Institute for Space Research and Kapteyn Astromomical Institute, 

University of Groningen, Netherlands 

K.F. Renk, B.I. Stahl 

Institut für Angewandte Physik, Universität Regensburg, Germany 

Semi-conductor devices based on diodes with Schottky barrier are widely used in room 

temperature applications in the THz frequency range. However, application of Schottky barrier 

diodes in these frequencies is limited by several factors: long time of carrier passage through 

the barrier and relatively large specific capacity. Shorter times of the response and a smaller 

value of the specific capacity can be achieved by creation of the diodes on the basis of semiconductor 

superlattices. The superlattice for diodes (length 112 nm) with 18 periods was grown 

by using molecular beam technology. Each period (length 6.22 nm) has 18 monolayers GaAs 

and 4 monolayers AlAs, and is homogeneously doped with silicon (2×10 18 cm -3 ). The 

minibandwidth of 25 meV was sufficient to lead to miniband rather than hopping transport 

behaviour. For these diodes we have also minimized values of series resistance R s and parasitic 

capacity C par of a substrate carrying the diode. The area of the active region of the diode was 

less than 2х10 -8 cm 2 . Measurement results of the output power level, efficiency and output 

harmonics content at room temperature are shown for the devices based on the new planar 

superlattice diodes for input frequency ranges 10-20 GHz, 78-118 GHz and 180-240 GHz. In 

this report the superlattice device applications as THz radiation sources are discussed. 

94


11-4 

A new experimental procedure for determining the response of bolometric detectors to fields in 

any state of coherence 

Cristopher Thomas and Stafford Withington 

Detector and Optical Physics Group, Cavendish Laboratory, University of Cambridge, JJ 

Thompson Avenue, Cambridge, CB3 0HE, UK 

Any bolometer that is greater than a few wavelengths in size is receptive to the power in a 

number of fully coherent optical modes simultaneously. Knowing the amplitude, phase, and 

polarisation patterns of these modes, and their relative sensitivities, is central to being able to 

use a multimode detector effectively. We describe a procedure for measuring the full spatial 

state of coherence to which a detector is sensitive. Diagonalisation of the coherence function 

then gives the natural modes. The scheme is based on the result that the expectation value of the 

output of any detector, or indeed whole instrument or telescope, is given by the contraction of 

two tensor fields, one of which describes the state of coherence of the incoming radiation, and 

the other describes the state of coherence of the field to which the detector is sensitive. It 

follows that if a detector is illuminated by two coherent point sources, in the near or far field, 

and the phase of one source rotated relative to the other, the output of the detector displays a 

fringe. By repeating the process with different source locations, the entire detector coherence 

tensor can be reconstructed from the recorded complex visibilities. This new, powerful 

technique is essentially aperture synthesis interferometry in reverse, and therefore many data 

processing techniques developed in the context of astronomy can be used for measuring the 

optical modes of bolometers. 

95


96


Session 12 – Optics & Components 


15:30 – 17:00 

Chair: Edward Tong 

15:30 - 15:45 12-1 Silicon Micromachined Components at Goutam Chattopadhyay, 

Terahertz Frequencies for Astrophysics JPL/Caltech 

and Planetary Applications 

15:45 - 16:00 12-2 Microfabrication Technology for All-Metal Vincent Desmaris, 

Sub-mm and THz Waveguide Receiver Chalmers University of 

Components 

Technology 

16:00 - 16:15 12-3 The fabrication and testing of novel Phichet Kittara, 

smooth-walled feed horns for focal Mahidol University 

plane arrays 

16:15 - 16:30 12-4 Optics Design and Verification for the Olle Nyström, 

APEX Single-Pixel Heterodyne Facility Chalmers University of 

Instrument 

Technology 

16:30 - 16:45 12-5 Backward Couplers Waveguide Alessandro Navarrini, 

Orthomode Transducer for 84-116 GHz INAF-Cagliari Astronomy 

Observatory 

16:45 - 17:00 12-6 Physical Optics Analysis of the ALMA Mark Whale, 

Band 5 Front End Optics 

NUI Maynooth 

97


12-1 

Silicon Micromachined Components at Terahertz Frequencies 

for Astrophysics and Planetary Applications 

Goutam Chattopadhyay, John Ward, and Harish Manohara 


4800 Oak Grove Drive, Pasadena, CA 91109, USA. 

ABSTRACT 

At frequencies beyond a few hundred gigahertz, the feature sizes of all but the simplest 

waveguide circuits are too small and the required tolerances are too demanding to be 

fabricated using even the best state-of-the-art conventional machining. On the other hand, 

silicon micromachining shatters the barriers of conventional machining, and brings the 

added benefits of rapid turn-around time and excellent process control. Furthermore, 

silicon micromachined circuits are light weight and capable of achieving a high degree of 

integration on a single chip. While there have been several demonstrations of waveguide 

circuits fabricated with silicon micromachining, few if any of these circuits have been 

subjected to any significant electrical testing. It can be argued that, to some extent, there 

exists a real disconnect between processing specialists who have demonstrated 

micromachined components and microwave engineers developing practical science 

instruments. There is a real need to establish the connection between processing 

specialists and microwave instrument developers to complete the cycle of designing, 

fabricating, and testing practical waveguide components that will be needed for future 

multi-pixel, multi-functional, high performance astrophysics and planetary instruments. 

JPL is using DRIE-based silicon micromachining capabilities to develop the critical 

waveguide components at submillimeter wavelengths that will lead to highly integrated 

multi-pixel spectrometers, imagers, and radars. The advantage of DRIE over wet 

anisotropic etching is that DRIE exhibits little crystal plane dependence and therefore 

reduces geometric restrictions. As a result, DRIE enables fabrication of trenches that are 

independent of crystal planes, thus making it possible to develop micromachined 

waveguides with vertical sidewall profiles. 

In this paper we will describe the design and performance of silicon micromachined 

critical waveguide components such as broadband quadrature-hybrid couplers, directional 

couplers, polarization twists, in-phase power dividers, and others operating in the range 

325-500 GHz (WR-2.2 waveguide band). One of the critical issues for micromachined 

components is the difficulty of testing the fabricated components, especially due to issues 

involving mating the silicon components to calibrated test equipment. We will discuss the 

design of a novel test fixture that we have developed at JPL to address these issues. 

The research described herein was carried out at the Jet Propulsion Laboratory, California 

Institute of Technology, Pasadena, California, USA, under contract with National 

Aeronautics and Space Administration. 

98


12-2 

Microfabrication Technology for All-Metal Sub-mm and THz Waveguide 

Receiver Components 

V. Desmaris*, D. Meledin, A. Pavolotsky, and V. Belitsky 

Group for Advanced Receiver Development (GARD), 

Chalmers University of Technology, S-412 96, Gothenburg,Sweden. 

It is well-known that the Maxwell’s equations’ solutions scales with frequency / wavelength, 

thus the fabrication of waveguide circuits gets more and more challenging as their operating 

frequencies enters the THz range. In fact, the constrains on the dimensional accuracy and surface 

quality become so stringent that conventional mechanical machining fails to deliver reproducible 

yield of waveguide circuits and components complying with (THz) tolerance requirements. 

We have developed [1] a new microfabrication technique based on copper electroforming 

over a patterned thick photoresist (SU-8). The use of photolithography for the waveguide 

structures’ layout definition provides sub-micrometric dimensional accuracy and exceptional 

surface quality of the fabricated structures. Furthermore, the lithographic nature of the proposed 

technique (possibility of stepping and processes repeating) makes it very suitable for the 

fabrication of component arrays for applications in multi-pixel receivers. 

a 

b 

Examples of produced all-copper waveguides components: (a) 385-500 GHz power divider; (b) 1.32 THz mixer 

back-piece with substrate channel, suspended microstrip line channel and waveguide backshort. 

We have successfully applied this technology for the fabrication of multilevel components 

for different Sub-mm and THz frequency bands from 200 GHz to 1.32 THz (see the figure 

above). We foresee this technology should be useful even at much higher frequencies (up to 

about 7 THz), providing that the active device size are handleable. 

At the conference, we present technology description with discussion and examples of the 

different waveguide components produced using our technique. 

[1]. V. Desmaris, D. Meledin, A. Pavolotsky, and V. Belitsky, “Sub-Millimeter and THz 

Micromachined All-Metal Waveguide Components and Circuits” – submitted to the IEEE 

Microwave and Wireless Components Letters. 

*contact e-mail: vincent.desmaris@chalmers.se 

99


12-3 

The fabrication and testing of novel smooth-walled feed horns for focal 

plane arrays. 

Authors: 

P. Kittara (*) email: tepcy@mahidol.ac.th 

J. Leech (+) , G .Yassin (+), B.K Tan (+), 

A. Jiralucksanawong (*) and S. Wangsuya (*). 

Affiliations: 

(+) Department of Physics, University of Oxford Keble, Oxon OX1 3RH, UK 

(*) Department of Physics, Mahidol University, 272 Rama VI Road, Bangkok, 

Thailand 


Corrugated horns have traditionally been used to give coupling to 

sub-mm detectors with low cross polarisation and sidelobe levels over 

a large bandwidth. Since they require the fabrication of many 

azimuthal grooves per wavelength into the walls of the horn, they can 

be difficult and expensive to manufacture at submillimetre 

wavelengths. This is a particularly difficult for large focal plane 

arrays, which require tens or hundreds of horns. In previous work, we 

presented designs for easy-to-machine, smooth walled horns which have 

performance comparable to corrugated horns. These horns have a few 

discontinuities in flare-angle along the length of the horn. The 

positions and magnitudes of the angular discontinuities are 

determined using a combination of modal matching analysis and a 

genetic algorithm optimisation. 

In this paper we present further investigations into these new types 

of feed horns including experimental results. In particular, we will 

describe a simple fabrication method which employs direct machining 

of horns into a block of aluminium using shaped drill bits. This 

method is very promising for the fast, inexpensive fabrication of 

large format focal plane arrays. We have now successfully used this 

fabrication method to manufacture many prototype horns at 230 GHz. We 

demonstrate the effectiveness of the manufacturing method by 

presenting beam pattern measurements for prototype horns across the 

230 GHz band. The method is particularly efficient at THz frequencies 

where corrugated horns are awkward to fabricate. To this end we will 

also present a horn design and pattern analysis at 1.3 THz. 

100


12-4 

101


12-5 

Backward Couplers Waveguide Orthomode Transducer for 84-116 GHz 

Alessandro Navarrini 1 and Renzo Nesti 2 

1 INAF-Cagliari Astronomy Observatory, Italy 

2 INAF-Arcetri Astrophysical Observatory, Italy 


We present the design and construction of a new waveguide Orthomode Transducer (OMT) for the 3 

mm band (84-116 GHz). The OMT is based on dual-side broadband backward coupler as illustrated in Fig 1. 

The device has a square waveguide input port (2.54×2.54 mm 2 ) that carries the two orthogonal linear polarized 

signals Pol 1 and Pol 2 associated with the TE 10 and TE 01 fundamental modes. The OMT single-mode 

waveguide outputs are a) a standard WR10 rectangular waveguide (2.54×1.27 mm 2 ) for Pol 2, and b) an oval 

waveguide with full-radius corners (external cross-section dimensions of 2.78×1.27 mm 2 ) for Pol 1. 

The OMT consists of a symmetric coupling structure in the common square waveguide arm that splits 

with opposite phases the incoming Pol 2 signal in two rectangular waveguide sidearms. Signal coupling 

to each sidearm is achieved by a broadband -3 dB E-plane branch-line coupler with four branches. The direct 

and forward coupled ports of each branch-line coupler are terminated with reactive loads provided, respectively, 

by a three-section transformer polarization discriminator in the common arm that reflects back all Pol 2 power, 

and by a short circuited three-step H-plane discontinuity in the rectangular waveguide sidearm. Therefore, the 

Pol 2 signals split by the coupling structure exit the two opposite sidearms traveling backward with respect to 

the original propagation direction. The signals emerging from these backward couplers travel through a 180 deg 

WR10 waveguide E-plane bend, a straight waveguide section, and a 90deg waveguide E-plane bend, before 

they are recombined by a 180deg E-plane Y junction waveguide power combiner that has a WR10 output. In 

the main arm, the signal associated with Pol 1 travels from a square waveguide to a rectangular waveguide 

trough a three-section transformer followed by an E-plane 90deg bend that brings out orthogonally to the main 

arm the oval cross section port. The oval waveguide is easy to machine and can be attached to a standard WR10 

producing a negligible power reflection. 

The OMT was optimized using the electromagnetic simulator CST Microwave Studio. The simulations 

predict a reflection coefficient at the square input port below -20 dB for both polarizations and a transmission 

loss at room temperature of, respectively, ~0.12 dB and ~0.30 dB, for Pol 1 and Pol 2. 

The OMT is fabricated with two mechanical blocks in split-block configuration using conventional 

CNC milling machine. Two OMTs are being machined and will be tested soon. 

The device is suitable for scaling to higher frequency. 

Fig 1 Left: 3D inner view of the backward couplers OMT. Right: Design of the mechanical blocks. The external 

dimensions of the assembled OMT are 19 × 30 × 33 mm 3 . Standard UG387 flanges are used at all ports. 

102


12-6 

103


104


POSTER PRESENTATIONS 

Nr. Title First author Institution 

THz Systems 

P1-1 Dome A, Antarctica: Prospectives for Terahertz 

Astronomy from the Ground 

Kulesa,Craig 


P1-2 Progress of Space Terahertz Technology in China Zhang, Cunlin Capital Normal University, 

Beijing,China 

HEB Mixers 

P2-1 Superconducting contacts and NbN HEB mixers 

performance 

P2-2 NbN HEB for THz radiation: technological issues and 

proximity effect 

P2-3 Development of 0.85 THz and 1.5 THz Waveguide 

NbTiN HEB Mixers 

P2-4 Development of membrane based NbN-HEBs for 

submillimeter astrophysical applications 

Bansal, Tarun 

Ilin,Konstantin 

Jiang,Ling 

Lefèvre,Roland 

TU Delft / SRON 

University of Karlsruhe 


LERMA 

P2-5 Integration of IF Amplifiers with NbTiN SHEB Mixers Pütz,Patrick KOSMA, 1. Physikalisches 

Institut der Universität zu Köln 

P2-6 Development of a 1.8-THz hot electron bolometric mixer 

for TELIS 

SIS Mixers 

Semenov,Alexei 


P3-1 AlN Barrier SIS junctions in submm heterodyne receiver: 

operational aspects 

Bout,Jeffrey 


P3-2 Formation of High Quality AlN Tunnel Barriers via an 

Inductively Coupled Plasma 

Cecil,Thomas 

University of Virginia 

P3-3 Design of finline SIS mixers with ultra-wide IF bands Grimes,Paul Oxford University 

P3-4 A 0.5 THz Sideband Separation SIS Mixer for APEX 

Telescope 

P3-5 A Balanced SIS Mixer System with Modular Design for 

490 GHz 

Monje,Raquel 

Pütz,Patrick 


Technology 

KOSMA, 1. Physikalisches 


P3-6 0.85-THz SIS Mixers with Vertically Stacked Junctions Wang,Ming-Jye Institute of Astronomy and 

Astrophysics, Academia 

Sinica, Taiwan 

Herschel-HIFI 

P4-1 The HIFI Focal Plane Beam Characterization and 

Alignment Status 

Jellema,Willem 


105



Direct Detectors 

P5-1 A Compact, Modular Package for Superconducting 

Bolometer Arrays 

P5-2 A novel thermoelectric multiplexer concept for arrays of 

superconducting bolometers 

Benford,Dominic 

Luukanen,Arttu 

NASA / GSFC 

Millimetre-wave Laboratory of 

Finland - MilliLab 

P5-3 Design of Superconducting Terahertz Digicam Matsuo,Hiroshi NAOJ 

P5-4 Recent work on a 600 pixel 4-band microwave kinetic 

inductance detector (MKID) for the Caltech 

Submillimeter Observatory 

P5-5 Thermal characterisation and noise measurement of 

NbSi TES for future space experiments 

P5-6 A Novel Thermal Detector for Far-Infrared and THz 

Imaging Arrays 

THz Receivers & Backends 

Noroozian,Omid 

Youssef,Atik 

Luukanen,Arttu 

California Institute of 

Technology 

CNRS-IAS 

Millimetre-wave Laboratory of 


P6-1 Distributed correlator for space applications Gunst,Andre ASTRON 

P6-2 CASIMIR – Caltech Airborne Submillimeter Interstellar 

Medium Investigations Receiver 

P6-3 Upgrade of the SMART Focal Plane Array Receiver for 

NANTEN2 

P6-4 New Challenge for 0.1 - 0.3 THz Technology: 

Development of Apparatus for Radiotelescope RT-70 

P6-5 Development of a Two-Pixel Integrated Heterodyne 

Schottky Diode Receiver at 183GHz 

Local Oscillators 

Miller,David 

Pütz,Patrick 

Vdovin,Vyacheslav 

Wang,Hui 

JPL 

KOSMA, 1. Physikalisches 


IAP RAS 

Observatoire de Paris 

P7-1 UTC-PD Integration for Submillimetre-wave Generation Banik,Biddut Chalmers University of 

Technology 

P7-2 DEVELOPMENT OF SUPERCONDUCTIVE 

PARALLEL JUNCTIONS ARRAYS FOR SUBMM- 

WAVE LOCAL OSCILLATOR APPLICATIONS 

P7-3 Sideband Noise Screening of Multiplier-Based Sub- 

Millimeter LO Chains using a WR-10 Schottky Mixer 

P7-4 Frequency tunability and mode switching of quantum 

cascade lasers operating at 2.5 THz 

P7-5 Capabilities of GaN Schottky multipliers for LO Power 

Generation at Millimeter-Wave Bands 

Boussaha,Faouzi 

Bryerton,Eric 

Pavlov,Sergey 

Siles,Jose V. 

LERMA - Obesrvatoire de 

Paris 

NRAO 


Universidad Politecnica de 

Madrid 

P7-6 High Power Heterostructure Barrier Varactor Quintupler 

Sources for G-Band Operation 

Vukusic,Josip 


Technology 

P7-7 Cryogenic Phase Locking Loop System for Flux-Flow 

Oscillator 

Khudchenko, 

Andrey 

Institute of Radio Engineering 

and Electronics / SRON 

106



Schottky Mixers 

P8-1 Fabrication of GaAs Schottky nano-diodes with T- 

Anodes 

P8-2 Towards a THz Sideband Separating Subharmonic 

Schottky Mixer 

P8-3 Ultrawideband THz detector based on a zero bias 

Schottky diode 

Jung,Cécile 

Sobis,Peter 

Sydlo,Cezary 

Observatoire de Paris 

Omnisys Instruments AB 

ACST GmbH 

ALMA 

P9-1 Tolerance analysis of the ALMA band 10 front-end 

optics 

Candotti,Massimo 

NAOJ 

P9-2 ALMA 183 GHz Water Vapor Radiometer Emrich,Anders Omnisys 

P9-3 Characterization of waveguide components for the 

ALMA band 10 

Kojima,Takafumi Osaka Prefecture University / 

NAOJ 

P9-4 Characterization of ALMA Calibration Targets Murk,Axel University of Bern 

P9-5 Near field beam and cross-polarization pattern 

measurements of ALMA band 8 cartriges 

P9-6 SIS Mixers for ALMA Band-10: Comparison of Epitaxial 

and Hybrid Circuits 

Novel Devices & Measurements 

P11-1 A semiconductor quantum dot for spectral sensitive 

detection of THz radiation 

P11-2 Epitaxial ultra-thin NbN films grown on sapphire 

dedicated for superconducting mixers 

Naruse,Masato 

Shitov,Sergey 

Davis,Ray 

Guillet,Bruno 

University of Tokyo, NAOJ 

NAOJ / IREE 

Royal Holloway Physics Dept 

GREYC CNRS 

P11-3 Terahertz emission from ZnSe nano-dot surface He,Shan State Key Laboratory of 

Optoelectronic Materials and 

Technologie 

P11-4 The response rate of a room temperature terahertz 

InGaAs-based bow-tie detector with broken symmetry 

Kašalynas,Irmantas Semiconductor Physics 

Institute 

P11-5 The precise resonator measuring technique at MM and 

THz waves 

P11-6 A 585 GHz Quasi-Optical HEB Six-Port Reflectometer 

Based on an Annular Slot Antenna 

P11-7 Solid-state non-stationary spectroscopy of 1-2.5 THz 

frequency range 

P11-8 NbN epitaxial SIS and SNS junctions on M-plane 

sapphire for THz detection 

Parshin,Vladimir 

Percy,Becca 

Vaks,Vladimir 

Villégier,Jean- 

Claude 

Institute of Applied Physics of 

RAS 


Institute for Physics of 

Microstructures RAS 

CEA-Grenoble, DRFMC 

107



Optics & Components 

P12-1 Design and Simulation of a Corrugated Polarizer and 

Waveguide-based OMT for a 129 GHz VLBI Receiver 

of KVN 

P12-2 Simulation of THz Receiver Systems Using Hybrid 

Numerical Methods and Spectral Ray Tracing 

Technique 

P12-3 Development of a 385-500 GHz Orthomode 

Transducer (OMT) 

P12-4 Simulation and Scaled Model Measurement of 

Membrane-based Twin Slot Antennas at 0.6 THz and 

2.5 THz 

P12-5 Terahertz Attenuator Based on the Sub-wavelength 

Metal Structures 

Chung,Moon-Hee 

Ehtezazi 

Alamdari,Iraj 

Kamikura,Mamoru 

Miao,Wei 

Zhao, Guozhong 

Korea Astronomy & Space 

Science Institute 

E&CE Dept. University of 

Waterloo 

NAOJ 

LERMA, Observatoire de Paris 

Department of Physics, 

Capital Normal University, 

Beijing, China 

– End of poster list – 

108


POSTER ABSTRACTS 

P1-1 

109


P1-2 

Progress of Space Terahertz Technology in China * 

Cunlin Zhang and Guozhong Zhao 

Department of Physics, Capital Normal University, Beijing 100037, China 

Cunlin_zhang@mail.cnu.edu.cn 

Terahertz science and technology attract more and more attentions of scientists and 

techniques in the recent years. The space terahertz technology is becoming into a hot spot in 

the field of the space research and the space application. We present the progress of space 

terahertz technology in china in this paper. Except for the exploring the application of 

terahertz technology on the space positioning, the remote sensing, and the monitoring of 

cosmic rays, and so on, we are focusing on the application of the new technologies of 

terahertz imaging on the space technology. Instead of the point-by-point scanning of terahertz 

imaging, we have developed the two-demission quasi-real time of terahertz imaging 

technology. The infrared CCD with the operating wavelength of around 800 nm is used for 

the imaging of terahertz field by the electro-optic sampling. The scope of imaging depends 

on the size of the electro-optic crystal. The corresponding software is explored based on the 

LabVIEW programming. The stand-off terahertz imaging by the CCD detection is going on 

the development based on the cooperation between the Institute of Space Technology of 

China and the key lab of Terahertz Optoelectronics of Education Committee in the Capital 

Normal University. We also present the future trend of space technology of china including 

the terahertz imaging technology. Finally the cooperation between China and Europe is 

suggested with concerning on the basis of technology cooperation of other field. It is helpful 

for all us to exchange the idea on the application of terahertz technology on the space 

research. 

* This work is supported by the Basic Research Program of China (973, Grant No. 2007CB310408 and 

2006CB302901) and Natural Science Foundation of Beijing (Grant No. 4073030)). 

110


P2-1 

Superconducting contacts and NbN HEB mixers performance 

T. Bansal 1,2 , P. Khosropanah 2 , W. Zhang 2,3 , J.R. Gao 1,2 , T.M. Klapwijk 1 , 

1 Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands 


3 Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, P.R. China 

email:T.bansal@tudelft.nl 

Phonon-cooled superconducting NbN hot electron bolometer (HEB) mixers are so far the 

only sensitive heterodyne detector at high frequencies beyond 1.5 THz. It is known that 

under operating conditions the parabolic electron temperature set up due to the absorbed LO 

power depends on the boundary conditions, related to the contact pads. 1 Earlier, we have 

reported that the sensitivity of such a mixer can depend on contact materials. The best 

sensitivities have been obtained by using a NbTiN superconductor layer between thin NbN 

and Au in the contacts. 2,3 

In this work we replace the 10nm thick NbTiN with 10 nm thick Nb. The motivations are: a) 

Gain a new insight of the role of the contacts and ultimately the physics; b) Nb process is 

much more widely available; c) Establish a more reproducible fabrication process. 

We have succeeded in realizing HEB mixers using both contacting materials on a single 

wafer with the same fabrication steps except for the contacting materials. The bolometer is 

based on a typical thin NbN film 4 grown on a Si substrate with a critical temperature of 9.5 

K. The bolometer has a dimension of 0.2 μm×2 μm and is terminated by a spiral antenna 

with an upper cut-off frequency of ~6 THz. We are currently evaluating the heterodyne 

performances of both types of mixers. The first device of HEBs with Nb contacts has 

demonstrated a DSB receiver noise temperature of 1230 K at 2.5 THz at the optimal LO 

power (190 nW) and bias and using an uncoated Si lens. This value was measured directly by 

recording the output noise power responding to hot/cold loads at the same bias current 5 . If we 

correct the loss due to the absence of the antireflection coating, we expect to reduce this 

noise temperature to 980 K, which is practically same as the best performance reported at this 

frequency from a NbTiN contacted HEB previously 2 . 

References: 

1. R. Barends, M. Hajenius, J. R. Gao, T.M. Klapwijk, “Current inducd vortex unbinding in bolometer mixers”, Appl. 

Phys. Lett, 87, 263506 (2005). 

2. M. Hajenius, J. J. A. Baselmans, J. R. Gao, T.M. Klapwijk, P. A. J. de Korte, B. Voronov and G. Gol’tsman, “Low 

noise NbN superconducting hot electron bolometer mixers at 1.9 and 2.5 THz”, Supercond. Sci. Technol. 17, S224– 

S228 (2004). 

3. J. J. A. Baselmansa, M. Hajenius, J. R. Gao, T. M. Klapwijk, P. A. J. de Korte, B. Voronov and G. Gol’tsman 

“Doubling of sensitivity and bandwidth in phonon cooled hot electron bolometer mixers” Appl. Phys. Lett, 84, 1958- 

1961 (2004). 

4. The NbN thin film was provided by SCONTEL, Moscow, Russia ( http:/www.scontel.ru). 

5. P. Khosropanah, J. R. Gao, W. M. Laauwen, M. Hajenius, and T. M. Klapwijk, “ Low noise NbN hot electron 

bolometer mixer at 4.3 THz”, Appl. Phys. Lett. 91, 221111 (2007). 

111


P2-2 

NbN HEB for THz radiation: technological issues and proximity effect. 

K.S. Il’in, A. Stockhausen, M. Siegel 

Institute for Micro- and Nanoelectronic Systems University of Karlsruhe, Karlsruhe, 

Germany 

A.D. Semenov, H.-W. Huebers 

DLR Institute of Planetary Research, Berlin, Germany 

The phonon-cooled hot-electron bolometer (HEB) detectors made from ultra-thin NbN films 

are known devices with low noise level and high detection speed suitable for operation in 

THz spectral range. In spite of more than two decades history of these devices their 

performance has to be further improved to fulfill requirements of particular applications. The 

HEB THz detector is a complex system consisting of several parts those properties and 

mutual influence has to be accounted for further effective development of the device. 

The hot-electron bolometer detector is a rectangular detecting element made from ultra-thin 

superconducting film whose length is restricted by the antenna arms, which are made from a 

thick layer of normal metal with low surface resistance. Reduction of thickness of 

superconducting film, which is required to improve an escape process of hot phonons from 

film to substrate, results in reduction of the critical temperature of superconducting transition 

of NbN films. Additionally, superconductivity in the NbN film will by suppressed by the 

proximity effect with the antenna arms. Contrary, decrease of the interface transparency 

between NbN film and the antenna will decrease inter-diffusion efficiency of Cooper pairs 

and quasi-particles and weaken the proximity effect. At the same time reduction of the 

interface transparency results in an increase in the losses of the RF current flowing though 

the antenna into the superconducting detecting element and thus causes deteriorating device 

performance. 

We present results on the development of technology and the study of the intrinsic and 

artificial proximity effects in hot-electron bolometer detectors based on thin NbN films. The 

NbN films are deposited by magnetron sputtering of Nb target in the reactive gas mixture of 

argon and nitrogen. A critical temperature of about 9.5 K is reached for NbN films with a 

thickness of about 5-6 nm. The two times increase of the NbN film thickness results in an 

increase in T C up to 12 K. An antenna structure consists of gold layer and in situ sputtered 

buffer layer of NbN. Interplay between fabrication conditions, geometry, superconducting 

and normal state properties of the device will be presented and discussed. 

112


P2-3 

Development of 0.85 THz and 1.5 THz Waveguide NbTiN HEB Mixers 

L. Jiang 1 , S. Shiba 1 , K. Shimbo 1 , M. Sugimura 1 , S. Yamamoto 1 , H. Maezawa 2 , and S. C. 

Shi 3 

1 Department of Physics, Faculty of Science, The University of Tokyo, Tokyo, Japan 

2 Solar-Terrestrial Environment Laboratory (STEL), Nagoya University, Nagoya, Japan 

3 Purple Mountain Observatory, NAOC, CAS, Nanjing, China 

In this paper we will present the development of 0.85 THz and 1.5 THz waveguide hotelectron 

bolometer (HEB) mixers with superconducting NbTiN ultra-thin film deposited 

on quartz substrate under the circumstance of a 4-K close-cycled refrigerator. This 

investigation is targeted toward potential use in a 1.5 THz NbTiN superconducting HEB 

receiver for observing some fine structure lines such as NII and rotational lines of some 

molecules such as CH and HD + 2 . With a THz receiver of high sensitivity and high velocity 

resolution, it is highly possible to diagnose physical and chemical conditions of interstellar 

clouds. 

The NbTiN and Au bilayers are sputtered on the quartz substrate without breaking 

vacuum, which reduces natural oxidation of the NbTiN surface. The waveguide probe and 

the RF choke filter consist of 350 nm thick Al film and 45 nm Nb film for easy bonding. 

The RF embedding circuit is optimized based on the current waveguide mixer block 

structure. The uncorrected receiver noise temperature of 900 K is obtained at 800 GHz for 

the 3.5 μm (width) × 0.4 (length) μm HEB mixer of 12 nm thick NbTiN film. Total 

receiver conversion loss, IF gain bandwidth and noise bandwidth, LO power requirement, 

and IF-output-power stability of the waveguide superconducting NbTiN HEB mixers of 

different microbridge volumes at 0.85 THz and 1.5 THz are thoroughly measured. In 

addition, we optimize the sputtering parameters such as substrate temperature, N 2 flow 

rate, Ar flow rate, and Ar plasma cleaning time to obtain the high quality ultra-thin NbTiN 

film of 5-6 nm thickness. 

113


P2-4 

Development of membrane based NbN-HEBs for submillimeter astrophysical 

applications. 

R. Lefèvre a , Y. Delorme a , A. Feret a , F. Dauplay a , M. Wei a , L. Pelay a , B. Lecomte a 

B. Guillet b , G. Beaudin a and J.-M. Krieg a 

a LERMA, Observatoire de Paris, UPMC, CNRS, 77 av. Denfert-Rochereau, 75014 Paris, France 

b GREYC ENSICAEN, 6 bd Maréchal Juin, 14050 Caen, France 


We are developing membrane based NbN hot electron bolometer (HEB) arrays for 

submillimeter astrophysical applications. 

Here we report in detail on the device fabrication process using a silicon oxide based resist 

(HSQ). The e-beam patterned HSQ is used as a mask in reactive ion etching for HEB 

definition and then remains on top of the HEB providing protection against contamination. 

This process is relatively simple since it requires less steps than previously reported and 

therefore reduces the risk of degradation of the ultra thin NbN film. 

To get good quality membranes for THz-HEB applications, different membrane process 

have been investigated. Electrical characterisations have been performed at room and 

cryogenic temperatures to compare the quality of the devices with membranes made up of 

Si/SiO or SiN/SiO and processed with either dry or wet etching methods. 

114


P2-5 

Integration of IF Amplifiers with NbTiN SHEB Mixers 

P. Pütz 1 , C.E. Honingh 1 , M. Justen 1 , K. Jacobs 1 

J. Bardin 2 , H. Mani 2 , S. Weinreb 2 

1 KOSMA, 1. Physikalisches Institut der Universität zu Köln, Germany 

2 Department of Electrical Engineering, California Institute of Technology, Pasadena CA 91125 

For the 1.4 THz and 1.9 THz channels of the GREAT instrument for SOFIA we have 

developed waveguide mixers with NbTiN superconducting Hot Electron Bolometer (SHEB) 

devices on low stress silicon nitride membranes. Comparable mixers will also be used in the 

balloon-borne Stratospheric Terahertz Observatory (STO). In the current baseline approach 

for these receivers, the mixer is connected to the low noise IF amplifier by a narrow-band 

(1.2–1.8 GHz) cryogenic isolator to prevent interactions between the 1–2 GHz amplifier and 

the mixer. Previous tests have indicated that an isolator is necessary for a stable receiver 

performance with minimal variations of noise and gain vs. IF frequency. Unfortunately, the 

isolator has the disadvantage that a significant fraction of the potential IF bandwidth of the 

mixer and low noise IF amplifier is wasted. 

Several approaches are currently being pursued for wide-bandwidth integration of mixers and 

IF amplifiers and experimental results will be reported at the conference. A first approach is 

a connection of a Caltech 0.5–11 GHz indium-phosphide LNA directly to the mixer without 

an isolator; initial results have shown large frequency ripple in the measured receiver noise 

temperature. The amplifier has excellent noise and flat gain when driven from a 50 ohm 

generator but does not present a 50 ohm load to the HEB mixer at IF frequencies below 4 

GHz. The use of a small attenuator between LNA and mixer will be investigated. Finally, a 

new silicon-germanium (SiGe) LNA for the 0.3 to 5 GHz range with good input match is 

under test at Caltech and further tests of integration with the HEB mixer are planned prior to 

the conference. 

115


P2-6 

Development of a 1.8-THz hot electron bolometric mixer for TELIS 

A.D. Semenov, H. Richter, and H.-W. Hübers 

Institute of Planetary Research, German Aerospace Center (DLR) 


(Email: Alexei.Semenov@dlr.de) 

P. Khosropanah 

SRON Netherlands Institute for Space Research, 

Landleven 12, 9747 AD Groningen, The Netherlands 

M. Hajenius, J. R. Gao, and T.M. Klapwijk 

Kavli Institute of NanoScience, Delft University of Technology, 

Lorentzweg 1, 2628 CJ Delft, The Netherlands 

TELIS (TErahertz and submm LImb Sounder) is a new state-of-the-art balloon borne three 

channel (0.5, 0.6, and 1.8 THz) cryogenic heterodyne spectrometer, which will allow limb 

sounding of the Earth’s atmosphere within the submillimeter and far-infrared spectral range. 

The instrument is being developed by a consortium that includes the Space Research 

Organization of the Netherlands (SRON), the Rutherford Appleton Laboratory (RAL) in the 

United Kingdom and the German Aerospace Center (DLR, lead institute). TELIS will utilize 

state-of-the-art superconducting heterodyne technology and is designed to be compact and 

lightweight, while providing broad spectral coverage, high spectral resolution and an 

operation time larger than the typical flight duration (≈24 hours) in a single campaign. The 

combination of high sensitivity and extensive flight duration will allow investigation of the 

diurnal variation of key atmospheric short-lived radicals such as OH, HO 2 , ClO, BrO 

together with stable constituents such as O 3 , HCl and HOCl. 

Here we report measurement results of a planar double-slot antenna HEB mixer for 1.8 

THz channel on TELIS. The HEB, based on a thin NbN film 1 on a high resistivity silicon 

substrate, has a dimension of 1.5×0.2 μm 2 . The HEB chip is glued to the rear side of a 12- 

mm diameter elliptical lens that has an anti-reflection coating from parylene. The DSB noise 

temperature was measured with an optically pumped THz gas laser operating at 1.9 THz. At 

an intermediate frequency (IF) of 1.5 GHz the noise temperature is 1500 K. Within the IF 

band of TELIS it increases from 3000 K at 4 GHz to ∼4500 K at 6 GHz. The antenna beam 

pattern was measured by scanning a hot source across the field-of-view of the mixer. The 

sidelobes are below -15 dB. Hence, the mixer fulfills the requirements set by TELIS. 

1. The NbN film was provided by Moscow State Pedagogical University, Moscow, Russia. 

116


P3-1 

AlN Barrier SIS junctions in submm heterodyne receiver: operational 

aspects. 

J. Bout 2 , A. Baryshev 1.2 , F.P. Mena 1,2 , R. Hesper 1,2 , B. Jackson 2 , W. Wild 1,2 , 

C.F.J. Lodewijk 3 , D. Ludkov 3 , T. Zijlstra 3 , E. van Zeijl 3 , T.M. Klapwijk 3 

1 

SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen, The Netherlands 

2 

Kapteyn Astronomical Institute, University of Groningen, Landleven 12, 9747 AD Groningen, The 


3 

Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology Lorentzweg 1, 

2628 CJ Delft, The Netherlands 

The Atacama Large Millimeter Interferometer (ALMA) is an observatory which consists of 

more than fifty 12 meter diameter submm telescopes, located at an altitude of 5000 m in the 

Atacama desert in Chile. It covers the 30-950 GHz frequency range which is divided into ten 

bands following the atmospheric transmission windows. ALMA front-ends will be using an 

Superconductor-Insulator-Superconductor (SIS) heterodyne mixers as the key sensitive 

elements for all of its high frequency bands. 

The ALMA band 9 receiver which covers 600 - 720 GHz is being developed in the 

Netherlands. The first eight receivers have been already built based on AlOx barrier SIS 

junctions mixers. These mixers have excellent noise temperature but show limited RF and IF 

bandwidth. Using new AlN barrier higher current density SIS junctions, it is possible to 

improve on the RF and IF bandwidth of SIS mixers thus making this technology 

significantly more attractive for the use in large series of SIS receivers. 

In this paper a careful comparison of the performance and operation of ALMA band 9 

receivers based on AlN and AlOx barrier mixer will be presented. Sensitivity, IF/ RF 

coverage as well as stability and linearity of receivers will be compared based on 

experimental data. Routines for Josephson noise suppression in AlOx barrier mixers will be 

discussed in detail and its adaptation to AlN barrier mixer operation will be reported. 

117


P3-2 

Formation of High Quality AlN Tunnel Barriers via an Inductively Coupled Plasma 

Thomas W. Cecil, Arthur W. Lichtenberger, and Anthony R. Kerr 

Thomas Cecil and Arthur Lichtenberger are with the Charles L. Brown Department of 

Electrical and Computer Engineering at the University of Virginia. Anthony Kerr is with the 

National Radio Astronomy Observatory 

Increasing the operating frequency of SIS receivers requires junctions that can 

operate at higher current densities. A major limiting factor of higher current density junctions 

is the increase in subgap leakage that occurs in AlO X barriers as current densities approach 

and exceed 10kA/cm 2 . AlN insulators are a promising alternative due to their lower leakage 

current at these high current densities. However, these barriers are more complicated to 

fabricate – requiring a plasma to crack the diatomic nitrogen molecules - and problems with 

achieving reproducible current densities have been reported. 

In this paper we present on the synthesis of AlN barriers using an inductively coupled 

plasma (ICP) source. The ICP allows for independent control of ion energy and current 

density in the plasma. Additionally, plasmas with very low ion energy (~20eV) and a high 

degree of dissociation (~80%) can be achieved. This improved control allows for the 

repeatable synthesis of high quality barriers. We report on the relationship between barrier 

thickness and plasma conditions as determined by in-situ discrete ellipsometry. Ellipsometry 

results were verified by fabricating Nb/Al-AlN/Nb junctions and measuring current-voltage 

curves. Curves for a range of current densities are presented. 

118


Design of finline SIS mixers with ultra-wide IF bands 

P3-3 

Paul Grimes, Ghassan Yassin 

Astrophysics, 

University of Oxford, 

Denys Wilkinson Building, 

Keble Road, 

Oxford, OX1 3RH,UK. 

pxg@astro.ox.ac.uk 

The instantaneous bandwidth of heterodyne receivers is defined by their IF 

bandwidth. This bandwidth limits the sensitivity of SIS based receivers 

to continuum emission and limits the instantaneous frequency range for 

spectroscopic observations. New telescopes and backend processing 

technologies have led to demands for ever wider IF bandwidth SIS mixers. 

We present the design of 230 GHz finline SIS mixers with a 2-20 GHz IF 

band. These mixers are intended for use in a prototype high brightness 

sensitivity, low spatial resolution interferometer for Sunyaev-Zeldovich 

effect measurements that is currently under construction in Oxford. The 

first batches of these devices have recently been fabricated at KOSMA, 

University of Cologne, and will soon be undergo initial testing in Oxford. 

The finline coupled mixer design is particularly suitable for use with 

very wide IF bandwidths, as the finline transition provides a clean 

transition from waveguide to microstrip, and allows all of the RF tuning 

and IF circuits to be fabricated in planar circuit. This removes many of 

the problems of grounding the mixer and allows relatively large IF 

contacts and circuits to be included on the mixer chip. 

The first wide IF band finline SIS mixers use the antipodal finline 

transition (as featured on our previous finline mixers and detectors) on 

quartz substrate to couple the input waveguide to the mixer's microstrip 

circuits. RF bandpass filters made up of microstrip and anodised niobium 

capacitors are used to provide isolation between the finline and the IF 

circuits. Two RF tuning designs have been used. In the first design a 

single SIS junction is tuned by a single series stub, terminated by a 

stepped microstrip RF choke. In second design, two SIS junctions are used 

in a single-ended dual junction tuning circuit, in conjunction with the 

same stepped microstrip choke. 

The 16 Ohm output impedance of SIS mixer is matched to the 50 Ohm input 

impedance of the cryogenic IF amplifier using a 5-stage stepped microstrip 

transformer fabricated on Rogers/Duroid 6010LM. The design of this 

transformer is also used to tune out the inductance of the bondwires 

connecting the mixer chip to the transformer. 

We are currently designing a finline SIS mixer utilising SOI substrate 

technology and beam lead connections to the IF circuit, with greatly 

reduced parasitic inductance in the IF connection. We have also developed 

a transition direct from unilateral finline to microstrip or coplanar 

waveguide transmission line that will allow the design of 50 Ohm 

characteristic impedance finline mixers, removing the need for IF matching 

transformers, as well as being significantly shorter than the current 

antipodal finline transition. Designs for these mixers will be also be 

presented. 

119


P3-4 

120


P3-5 

A Balanced SIS Mixer System with Modular Design for 490 GHz 

M. Justen, C.E. Honingh, T. Tils, P. Pütz, K. Jacobs 

KOSMA, 1. Physikalisches Institut der Universität zu Köln, Germany 

We present measurements on a balanced mixer system for 490 GHz. The system consists of a 

central -3 dB branchline waveguide coupler, which has been fabricated in split-block 

technique in the KOSMA workshop. The coupler connects the two SIS mixers and two feed 

horn antennas. A corrugated horn is used for the signal from the telescope and a diagonal 

horn with the same beam parameters is used to feed the coupler with the LO signal. 

The modular design allows the characterization of every component separately. In particular, 

various waveguide couplers have been investigated with a vector network analyzer at their 

respective operating frequencies at the University of Bern [1]. The SIS mixers have been 

tested in standard double sideband mode and demonstrate 60–80 K noise temperature over 

the RF band. 

These results are compared with simulations and with measurements of the entire balanced 

mixer in order to gain insight into function and interaction of the different components as 

well as into critical fabrication tolerances. 

Fig. 1 The modular balanced mixer, mounted to 

the cold optics. 

[1] M. Justen, T. Tils, P. Pütz, A. Murk, C.E. Honingh, K. Jacobs. RF and IF couplers for a 

sideband separating SIS waveguide mixer for a 345 GHz focal plane array. In Proceeding of 

the ISSTT 2006. 

121


0.85-THz SIS Mixers with Vertically Stacked Junctions 

P3-6 

Ming-Jye Wang 1 , Tse-Jun Chen 1 , Chuang-Ping Chiu 1 , Hsian-Hong Chang 2 , Jing Li 3,4 , and 

Sheng-Cai Shi 3 

1. Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan 

2. Department of Physics, National Tsing-Hua University, Hsin-Chu, Taiwan 

3. Purple Mountain Observatory, NAOC, CAS, China 

4. Graduate School of Chinese Academy of Science, CAS, China 

Vertically stacked SIS junctions (VSJ), with individual junctions connected in series but without 

introducing any additional connection wires, has been demonstrated to be used as a mixer at frequency of 

100GHz [1]. VSJ has a simple structure and an equivalent normal-state resistance of relatively large value, 

which may make impedance matching easier in mixer application. In addition, the dynamic range of VSJ 

mixer can improved by factor of N 2 [2, 3], where N is the number of stacked SIS junctions. Recently, the 

coherent THz source has been demonstrated in high temperature superconductor which has intrinsic 

stacked Josephson junctions [4]. It is interesting if the coherent IF can be detected in a VSJ mixer. 

We propose to develop a 0.85-THz superconducting SIS mixer with two vertically stacked 

Nb/AlOx/Nb junctions incorporating with two types of integrated tuning circuits, i.e., tuning inductance in 

series (end loaded) and shunted inductance followed with a quarter-wavelength open stub. Notice that the 

former still needs a section of impedance transformer, and the latter can be directly connected to the 

mixer-mount’s feed point. The designed junction critical current density and junction area are equal to 

7kA/cm 2 and 1μm 2 , respectively. Numerical simulations demonstrate that the shunted-inductance design 

has a superior performance in both noise temperature and bandwidth. Nb/Al-AlOx/Nb/Al-AlOx/Nb 

multilayer is deposited in as single vacuum process by standard Nb-technology. The VSJ is defined by 

etching the top three layers (Nb/Al-AlOx/Nb) using ICP-RIE system. The thickness of middle Nb can be 

varied to study the coherent IF generation in a VSJ mixer. Detailed simulation results and preliminary 

experimental results will be presented. 

[1] V. Yu. Belitsky, S.W. Jacobsson, S. A> Kovtonjuk, E.L. Kollberg, and An. B. Ermakov, International 

Journal of Infrared and Millimeter waves, 14, 5, pp.949-957, 1993 

[2] S. Rudner, M.J. Feldman, E. Kollverg, and T. Claeson, Journal of Applied Physics, 52, 10, pp.6366- 

6376, 1981 

[3] D.G. Grete, W.R. McGrath, P.L. Richards, and F.L. Lloyd, IEEE transaction on MTT, MTT-35, 4, 

pp.435-440, 1987 

[4] L. Ozyuzer, A. E. Koshelev, C. Kurter, N. Gopalsami, Q. Li, M. Tachiki, K. Kadowaki, T. Yamamoto, 

H. Minami, H. Yamaguchi, T. Tachiki, K. E. Gray, W.-K. Kwok, and U. Welp, SCIENCE, 318, pp.1291- 

1293, 2007 

122


P4-1 

The HIFI Focal Plane Beam Characterization and Alignment Status 

Willem Jellema 1,2 , Marinus Jochemsen 3 , Tully Peacocke 4 , Lenze Meinsma 5 , Paul Lowes 6 , 

Stafford Withington 7 and Wolfgang Wild 1,2 

1 SRON Netherlands Institute for Space Research, P.O. Box 800, 9700 AV, Groningen, the Netherlands 

2 Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, 9700 AV, Groningen, the Netherlands 

3 ASML Netherlands B.V., De Run 6501, 5504 DR, Veldhoven, the Netherlands 

4 Department of Experimental Physics, NUI Maynooth, Co Kildare, Ireland 

5 Ontwerpburo ANNEX, Bellingeweer 16, 9951 AM, Winsum, the Netherlands 

6 SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA, Utrecht, the Netherlands 

7 Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom 

In this paper we present the results of the characterization program of the beams in the focal 

plane of the HIFI flight model. We discuss the beam properties, quality of alignment, 

instrument footprint, performance impact and compliance and compare the results to 

predictions based on lower-level characterization results and simulations. We finally 

conclude by presenting the expected properties at the sky by forward propagation through a 

telescope model. 

123


P5-1 

A Compact, Modular Package for Superconducting Bolometer Arrays 

Dominic J. Benford, Johannes G. Staguhn, and Christine A. Allen 

NASA / Goddard Space Flight Center 

As bolometer arrays grow to ever-larger formats, packaging becomes a more 

critical engineering issue. We have designed a detector package to house a 

superconducting bolometer array, SQUID multiplexers, bias and filtering 

circuitry, and electrical connectors. The package includes an optical filter, 

magnetic shielding, and has well-defined thermal and mechanical interfaces. 

An early version of this package has been used successfully in the GISMO 

2mm camera, a 128-pixel camera operating at a base temperature of 270mK. 

A more advanced package permits operation at lower temperatures by 

providing direct heat sinking to the SQUIDs and bias resistors, which generate 

the bulk of the dissipation in the package. Standard electrical connectors 

provide reliable contact while enabling quick installation and removal of the 

package. We describe how the design compensates for differing thermal 

expansions, allows heat sinking of the bolometer array, and features magnetic 

shielding in critical areas. We highlight the performance of this detector 

package and describe its scalability to 1280-pixel arrays in the near future. 

124


P5-2 

125


P5-3 

Design of Superconducting Terahertz Digicam 

H. Matsuo 1 , Y. Hibi 1 , H. Nagata 2 , S. Ariyoshi 3 , C. Otani 3 , M. Fujiwara 4 , H. Ikeda 2 

1NAOJ, 2 ISAS/JAXA, 3 RIKEN, 4 NICT 

We have been working on superconducting direct detectors with niobium tunnel junctions, 

the SIS photon detectors. The detectors have high dynamic range and fast response and also 

operate at higher temperature than bolometric detectors. But, there are some issues before 

we will apply the detector technology to future space programs. One is how to realize large 

format array with cryogenic readout electronics, others are how to improve sensitivity and 

wavelength coverage to make the most of low background space environments. 

We describe the design of integrated readout electronics for the superconductive imaging 

submillimeter-wave camera for 650 GHz observation. We are currently working on cryogenic 

integrating amplifiers with low noise and low power dissipation using SONY GaAs-JFETs. 

Based on the measurements of DC characteristics of GaAs-JFETs and single stage 

amplifiers, we now have a design of high gain amplifier and CTIA readout electronics. Small 

scale integrated circuit is also being fabricated including analog and digital circuits. 

We also address on sensitivity improvements of SIS photon detectors. Since the detector 

noise is limited by leakage current of tunnel junctions, it is essential to make better 

isolation barrier and decrease junction area. We will discuss on the current limitation and 

future prospects. Also addressed are the input coupling design and wider wavelength 

coverage. 

126


P5-4 

Recent work on a 600 pixel 4-band microwave kinetic inductance 

detector (MKID) for the Caltech Submillimeter Observatory 

O. Noroozian 1 , P. Day 2 , M. Ferry 1 , J.-S. Gao 1 , J. Glenn 3 , S. Golwala 1 , S. Kumar 1 , H. LeDuc 2 , 

B. Mazin 2 , H. T. Nguyen 2 , J. Schlaerth 3 , J. E. Vaillancourt 1 , A. Vayonakis 1 , J. Zmuidzinas 1 

1 California Institute of Technology, 2 Jet Propulsion Laboratory, 3 University of Colorado 

We report recent progress on a ~600 spatial pixel 4-band (750, 850, 1100, 1300 microns) 

camera (MKIDCam) for the Caltech Submillimeter Observatory (CSO). This work is based 

on extensive previous work on a 16 pixel 2-color demonstration camera tested at the CSO 

(see poster by A. Vayonakis et al.). 

Our camera focal plane will make use of three novel technologies: Microwave kinetic 

inductance detectors (MKID), photolithographic phased array antennae, and on-chip bandpass 

filters. An MKID is a highly multiplexable photon detector that uses the change in 

surface impedance of a superconducting quarter-wave coplanar-waveguide (CPW) resonator 

to detect light. The resonator is weakly coupled to a CPW feed line. The amplitude and phase 

of a microwave probe signal (at the resonance frequency) transmitted on the feed line past 

the resonator changes as photons break cooper pairs. Hundreds to thousands of resonators 

tuned to slightly different frequencies may be coupled to a single feed line resulting in an 

elegant multiplexing scheme to read out a large array. Our phased array antenna design 

obviates beam-defining feed horns. On-chip band-pass filters eliminate band-defining metalmesh 

filters. Together, the antennae and filters enable each spatial pixel to observe in all four 

bands simultaneously. Due to the large number of pixels the step and repeat capability of our 

photolithography system will be used to reduce the number of required masks and the field 

size in the fabrication process. 

In order to reduce frequency noise due to fluctuations in the dielectric constant of the 

substrate, we are exploring new resonator designs that use interdigitated capacitors to lower 

electric field concentrations around the resonator lines. 

Readout will be done with software-defined radio and will use microwave IQ modulation 

which has been demonstrated at the CSO. We are working on the implementation of an 

improved design using sixteen X5-400M commercial FPGA boards operating at room 

temperature. 

127


P5-5 

Thermal characterisation and noise measurement 

of NbSi TES for future space experiments 

Atik Youssef 

CNRS-IAS Bât. 121 Université Paris-sud 11 

Orsay 91405, France 

The principal observational demonstration of the theory of the Big-bang, the cosmic 

microwave background (CMB), has its maximum of intensity to the millimetre-length 

wavelengths. Instrumental progress allowed the development of bolometric detectors adapted 

to these wavelengths. Superconducting transition-edge sensors (TESs) are currently under 

heavy development to be used as ultrasensitive bolometers. In addition to good performance, 

the choice of material depends on long term stability (both physical and chemical) along with 

a good reproducibility and uniformity in fabrication. For this purpose we are investigating the 

properties of NbSi thin films. NbSi is a well-known alloy for use in resistive thermometers 

We are co-evaporating Nb and Si simultaneously. We present a full low temperature 

characterization of the NbSi films. In order to tune the critical temperature of the NbSi 

thermometers down to the desired range, we have to adjust the concentration of niobium in 

the NbSi alloy. In this experiment, we set for a Niobium concentration of 15%, to be able to 

run testings at a convenient temperature of 300mK. Tests are made using 4He-cooled 

cryostats, 300mK 3He mini-fridges, resistance bridge and a commercial SQUID. Parameters 

being measured are: critical temperature, resistance, sharpness of the transition and noise 

measurements. 

128


P5-6 

A Novel Thermal Detector for Far-Infrared and THZ imaging Arrays 

Pekka Rantakari and Arttu Luukanen 

Millimetre Wave Laboratory of Finland – MilliLab, Espoo, Finland 

Steven Deiker, Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, 

U.S.A. 

This paper reports on novel MEMS based thermal detector architecture, which could allow the construction of very 

large focal plane arrays of bolometers for far-infrared and THz imaging. The principal challenge in developing large 

format cryogenic bolometer arrays is related to the multiplexing and readout of cryogenic detectors. The readout 

architectures that are being developed and deployed are mostly based on Superconducting Quantum Interference 

Devices (SQUIDs), which are highly sensitive but also relatively complex devices and have shortcomings with respect 

to the robustness of SQUIDs for operation in nonideal condition. 

The detector architecture presented here is based on the transition-edge sensor (TES), which is integrated on the 

surface of a freestanding micro electro mechanical (MEM) switch (Fig. 1). The key idea in this architecture is in 

thermal switching and in transformation of TES output to voltage pulses for faster detection and simpler multiplexing 

and readout of detectors. 

Shunt resistor 

Superconducting meander 

I b 

I b 

MEMS switch 

Substrate (T=T b) 

Fig.1 Schematic drawing of the novel thermal detector architecture. Transition-edge sensor, consisting of 

superconducting thin film meander, is integrated on top of the MEMS switch. 

The TES on top of the MEMS switch is current biased slightly below its critical current. A shunt resistor is in parallel 

with the meander on the substrate. In the up-state of the MEMS switch, the TES is thermally well-isolated from the 

substrate at bath temperature of T b . Incident optical power absorbed to the film increases the temperature of the TES 

with time. The critical current of the superconducting meander get decreased with increasing temperature and when 

reaching the value of the bias current I b , the meander quenches and becomes dissipative causing voltage to build up 

across the meander and shunt resistor. This voltage is used for triggering the MEMS switch and when reaching the pullin 

voltage of the switch, the switch closes and the thermal conductance between the TES and the substrate get increased 

causing a fast cool-down of the film. As the film cools near to the bath temperature, it returns back to the 

superconducting state and the voltage disappears releasing the MEMS switch and the new thermal integration cycle 

begins again. The frequency of the voltage pulses generated in the detector is proportional to the incident optical power 

and the array of detectors can be read out through common readout line by amplitude multiplexing of the pulses 

facilitated by the choice of shunt resistance values. Figure 2 shows simulated voltage and displacement responses of the 

detector at T b = 4K for incident optical power of 4 pW. 

(a) 

f 

0 

( P ) 

opt 

= 

T C 

P 

opt 

( −T 

T − ( I I ) ) 

2/3 

c th 

1 

b c b c0 

P opt = incident optical power 

C th = the thermal capacitance of the detector 

T c = critical temperature of TES 

T b = bath temperature of the detector 

I c0 = critical current density of thin film meander 

I b = bias current 

(b) 

Normalized amplitude 

1 

0.8 

0.6 

0.4 

0.2 

0 

-0.2 

-0.4 

-0.6 

-0.8 

-1 

1 1.5 2 2.5 3 3.5 4 4.5 

Time (s) 

x 10 -3 

Fig. 2 The switching frequency of the detector with certain assumptions (a) and the simulated normalized voltage 

(solid line) and displacement (dodded line) of the MEMS based thermal detector (b). 

In this paper, we will introduce the detector architecture and show the detector operation principle with analytical 

methods and with time domain simulations. Also, a noise model for the detector will be derived. 

129


P6-1 

Title: Distributed correlator for space applications 

Authors: A.W. Gunst, A. Bos, L. Venema 

Affiliation: ASTRON, the Netherlands 

For radio telescopes on Earth it is quite common to use a centralized correlator. This is used 

because the data of all the antennas need to be correlated with each other and therefore 

routing all the data to a central place is natural. However, in space the power dissipation and 

size is limited per satellite and hence a distributed correlator can be more advantageous. This 

also spreads the risk of failures. 

In this paper the proposed architecture for a distributed correlator in space is discussed. 

Furthermore, the effect of a number of design parameters on the estimated size and power 

consumption is also overviewed. 

130


P6-2 

CASIMIR – Caltech Airborne Submillimeter Interstellar 

Medium Investigations Receiver 

David Miller, Michael L. Edgar, Alexandre Karpov, Sean Lin, Simon J. E. Radford, Frank Rice, 

Jonas Zmuidzinas (Caltech), Andrew I. Harris (U. Maryland), and Neal Erickson (U. Massachusetts) 

CASIMIR, the Caltech Airborne Submillimeter Interstellar Medium Investigations 

Receiver, is a multiband, far-infared and submillimeter, high resolution, heterodyne 

spectrometer under development for SOFIA. It is a first generation, PI class instrument, 

designed for detailed, high sensitivity observations of warm (100 K) interstellar gas, both in 

galactic sources, including molecular clouds, circumstellar envelopes and protostellar cores, 

and in external galaxies. Combining the 2.5-meter SOFIA mirror with state of the art 

superconducting mixers will give CASIMIR unprecedented sensitivity. Initially, CASIMIR 

will have four bands: 550 GHz, 750 GHz, 1000 GHz, and 1250 GHz; with a fifth band under 

development at 1400 GHz. Any four bands will be available on each flight, contributing to 

efficient use of observing time. All the CASIMIR bands use advanced Superconductor- 

Insulator-Superconductor (SIS) mixers fabricated with Nb/AlN/NbTiN junctions in the JPL 

Micro Devices Lab. These planar mixers are quasi-optically coupled using twin slot 

antennas, and silicon hyperhemisphere lenses with Parylene antireflection coatings. With 

ongoing development, expectations are for DSB noise temperatures to improve to 3 hv/k at 

frequencies below 1 THz, and 6 hv/k above 1 THz. Each band uses a tunerless solid state 

local oscillator mounted on the outside of the two cryostats, with injection to the mixers via 

mylar beamsplitters. The optics box supporting the cryostats is open to the telescope cavity 

and contains the relay optics and calibration systems. Besides the cryostat windows, all 

optics are reflective and can accommodate the entire 8’ telescope field of view. Bias 

electronics and warm IF amplifiers are mounted on the cryostats, while electronics racks 

contain backend spectrometers, control electronics, and power supplies. CASIMIR will have 

two spectrometers available for processing the 4-8 GHz IF bandwidth. The entire instrument 

is about 1.5 m long, 1 m diameter, and weighs about 550 kg. CASIMIR embodies a versatile 

and modular design, able to incorporate future major advances in detector, LO and 

spectrometer technology. 

CASIMIR will enable the study of fundamental rotational transitions of many 

astronomically significant hydrides and other molecules. Observations of these species can 

provide critical tests of our understanding of interstellar chemical networks and reactions. 

The chemistry of oxygen in interstellar clouds is poorly understood, due to the opacity of the 

atmosphere and limited ground observations to many of its key species, such as O, O 2 , H 2 O, 

H 2 O + , and OH. The H 2 D + ion is of particular interest, as it is the deuterated version of H 3 + , 

which is believed to be responsible for driving much of the chemistry of molecular clouds. 

Water vapor plays an important role in the energy balance of molecular clouds by mediating 

radiative heating and cooling through its rotational transitions in the far infrared and 

submillimeter. CASIMIR will allow the study of the abundance and distribution of 

interstellar water with exceptional sensitivity and spatial and spectral resolution. In its initial 

four bands, CASIMIR can detect nine rotational transitions of the rare H 2 18 O istopomer, 

including several lines near the ground state. 

131


P6-3 

Upgrade of the SMART Focal Plane Array Receiver for NANTEN2 

U.U. Graf, C.E. Honingh, K. Jacobs, M. Justen, P. Pütz, M. Schultz, S. Wulff, J. Stutzki 

KOSMA, 1. Physikalisches Institut der Universität zu Köln, Germany 

We present the recent upgrade to the KOSMA SMART 2x 8-pixel dual-color focal plane 

array receiver. The 460–490 GHz channel has been upgraded from 4 to 8 pixels. We use 

standard tunerless waveguide mixers with corrugated horns and all-Niobium single junction 

SIS devices. The measured noise temperatures are around 70 K over the RF band for an IF of 

3.5–4.5 GHz for all pixels. At the IF the receiver is enhanced with new bias-tees and low 

noise MMIC amplifiers developed at Caltech. 

In the 800–880 GHz channel, devices with NbTiN-SiO 2 -Al tuning structures replace older 

SIS devices with Al-SiO 2 -Al tuning microstrip circuits. Their fabrication at KOSMA’s 

nanofabrication facilities utilizes electron beam lithography and chemical-mechanical 

planarization processing steps developed for the HIFI Band 2 devices. These devices need 

less local oscillator power, which facilitates the upgrade from 4 to 8 pixels. Measured noise 

temperatures per pixel are between 250 K and 300 K over the RF band for an IF of 4–8 GHz. 

In SMART the IF band is 1–2 GHz in order to simultaneously cover the CO 7-6 and the 3 P 2 - 

3 P 1 Carbon lines at 807 GHz and 809 GHz in the lower and upper sidebands. All noise 

temperatures are measured with a 13 µm thick Mylar beam splitter, are uncorrected and 

calculated according to the Callen-Welton formalism. 

The receiver is currently being installed at the KOSMA Gornergrat observatory. After a twomonth 

test run, it will be shipped to the NANTEN2 telescope in Chile to be installed as a 

facility instrument in time for the southern hemisphere winter. 

132


P6-4 

New Challenge for 0.1 - 0.3 THz Technology: 

Development of Apparatus for Radio Telescope RT-70 

V. Vdovin 1 , I. Zinchenko 1 

Yu. Artemenko 2 , V. Dubrovich 3 

A. Baryshev 4 

1 Institute of Applied Physics of Russian Academy of Sciences, Nizhniy Novgorod, Russia (IAP RAS) 

2 Astro Space Center of Lebedev Physical Institute of Russian Academy of Sciences, Moscow, Russia 

(LPI RAS) 

3 Special Astrophysical Observatory of Russian Academy of Sciences, St. Petersburg, Russia (SAO 

RAS). 

4 Institute of Radio-engineering and Electronics of Russian Academy of Sciences, Moscow, Russia 

(IRE RAS) 

The 70-m radio telescope is now under construction on plateau Suffa in Uzbekistan at an altitude of 

2500 m. It will have an actively controlled main mirror with the goal to achieve the shortest 

operational wavelength 1 mm. The project started many years ago but was frozen after USSR 

disintegration. The telescope support and the basic parts of the antenna were manufactured (Fig. 1). 

During the last few years the project has restarted and plans are being made to complete it in 

collaboration with Russia and Uzbekistan. The organization which is responsible for the project as a 

whole in Russia is the Astro Space Center of the Lebedev Physical Institute. 

The telescope should operate both in single-dish mode and as a part of VLBI networks, in 

particular in combination with planned radio telescopes in space such as Millimetron. The collecting 

area of the antenna greatly exceeds that of existing mm-wave facilities and is comparable to the total 

area of the ALMA antennas. This provides unprecedented capabilities for studies of compact faint 

objects which will be the primary targets for this instrument. The scientific program includes a wide 

range of astrophysical problems from studies of Solar system objects to the most distant radio galaxies 

and quasars. One of the most important tasks will be investigations of small scale primordial and 

secondary fluctuations of the CMB. For this task RT-70 will be significantly more efficient than a 

system of smaller telescopes like ALMA. 

In this report we mainly discuss the project status and development of the scientific instruments 

for this antenna which is still at a preliminary stage. They should incorporate the latest technological 

achievements and provide a superior performance over the operational frequency range. Both singlepixel 

and large format array (direct detection and heterodyne) receivers are considered. The receiver 

design is performed in the framework of a wide cooperation of Russian and Ukrainian organizations 

but is also open for the international community. 

The work is supported by the Program of Fundamental Researches of the Russian Academy of 

Sciences #5.2. “Electromagnetic THz- waves” and a special program Suffa project of ASC LPI RAS. 

Fig 1. The Suffa observatory with the radio telescope RT-70 now and after 2012. 

133


P6-5 

Development of a Two-Pixel Integrated Heterodyne Schottky 

Diode Receiver at 183GHz 

Hui Wang 1 , Alain Maestrini 3&1 , Bertrand Thomas 2 , Gérard Beaudin 1 

1 

Observatoire de Paris, LERMA, 61 avenue de l’Observatoire, 75014 Paris, France. 

2 

Rutherford Appleton Laboratory, Chilton Didcot, Oxfordshire, OX11 0QX, UK. 

3 

Université Pierre et Marie Curie-Paris6, LISIF, 75005 Paris, France. 

Abstract—in planetary and atmospheric sciences large arrays of millimetre wave 

heterodyne receivers can offer higher mapping speed and mapping consistency while 

avoiding the use of cryogenic receivers. To reduce the size, the weight and the power 

consumption of a multi-pixel receiver it is necessary to optimize the interface between the 

mixers and the local oscillator unit. One solution consists in integrating in the same 

mechanical block a frequency multiplier and one or several mixers to create a compact subarray. 

In this context, this paper will describe the design of a two-pixel Schottky diodebased 

heterodyne receiver working at 183GHz. The receiver is the integration of two 

183GHz subharmonic mixers and a frequency tripler into the same mechanical block. A Y 

junction divider is used to split the power produced by the frequency multiplier. The mixer 

and the tripler chips were both optimized independently for two stand-alone circuits. The 

chips have been fabricated using the standard BES process of United Monolithic 

Semiconductors (UMS) in the frame of a contract with CNES and ESA. The integrated twopixel 

receiver is expected to work in the band 170-195 GHz with a double side band (DSB) 

conversion gain greater than -5.5dB when pumped with less than 50mW of input power at 

30GHz. A minimum DSB conversion gain of -4.5dB at 183 GHz is expected. 

The design was performed at the Laboratoire d’Etude du Rayonnement et de la Matière en 

Astrophysique, Observatoire de Paris in collaboration with the Rutherford Appleton 

Laboratory. It was supported by the Centre National d’Études Spatiales, the Centre National 

de la Recherche Scientifique and AB Millimetre. 

Fig. On-wafer photograph of the 90GHz tripler (left) and 3D model of the prototype of two-pixel 

integrated Schottky diodes receiver (right). 

134


P7-1 

UTC-PD Integration for Submillimetre-wave Generation 

Biddut Banik, Josip Vukusic, Hans Hjelmgren, Henrik Sunnerud, Andreas Wiberg and Jan Stake 

Department of Microtechnology and Nanoscience, Chalmers University of Technology; 

SE-41296 Göteborg, Sweden (e-mail: biddut.banik@chalmers.se). 

Abstract: Because of the inherent difficulty to generate power in the frequency range 0.l-10 THz, the 

term ‘THz-gap’ has been coined. Among a number of MW/THz generation techniques, the 

photomixer based sources hold high potential offering wide tunability and decent amounts of output 

power. The photomixing technique relies on the nonlinear mixing of two closely spaced laser 

wavelengths generating a beat oscillation at the difference frequency. In recent years, there has been 

an increasing interest in the Uni-Travelling-Carrier PhotoDiode (UTC-PD) [1] for photomixing, 

photo receivers, MW/THz-wave generation, fibre-optic communication systems, and wireless 

communications. UTC-PDs have become very promising by demonstrating output powers of 20 mW 

at 100 GHz [1] and 25 µW at 0.9 THz [2]. 

Our ongoing research work concentrates on extending the previously accomplished UTC-PD 

fabrication and modelling techniques to ~300 GHz and above. We have already fabricated and 

characterised UTC-PDs intended for millimetre-wave generation. Several integrated antenna-detector 

circuits have been designed and characterised. Fig.1 (a) shows the SEM of a fabricated UTC-PD. 

Furthermore, in order to understand the device behaviour and its dependence on various factors, we 

have developed an accurate device model [3] implementing hydrodynamic transport model. The 

model has also enabled us to design and optimise the device for any specific application and target 

frequency [4]. 

Fig. 1. (a) SEM of a fabricated UTC-PD (b) antenna integrated UTC-PDs, and (c) waveguide integrated UTC-PDs. 

The current research-focus encompasses different integration approaches, and the construction of 

various antenna-integrated circuits and waveguide blocks that can be used as millimetre-wave (300 

GHz and above) generator for local-oscillator and free-space applications. Fig. 1 (b-c) shows several 

antenna integrated UTC-PDs and an example of the waveguide integrated UTC-PD. The designs of 

those blocks and integrated circuits, their fabrication and characterisation results will be presented. 

References: 

[1] H. Ito, T. Nagatsuma, A. Hirata, T. Minotani, A. Sasaki, Y. Hirota, and T. Ishibashi, "High-power photonic 

millimetre wave generation at 100 GHz using matching-circuit-integrated uni-travelling-carrier 

photodiodes," Optoelectronics, IEE Proceedings, vol. 150, pp. 138-142, 2003. 

[2] C. C. Renaud, M. Robertson, D. Rogers, R. Firth, P. J. Cannard, R. Moore, and A. J. Seeds, "A high 

responsivity, broadband waveguide uni-travelling carrier photodiode," Proceedings of the SPIE, vol. 6194, 

pp. 61940C, 2006. 

[3] S. M. M. Rahman, H. Hjelmgren, J. Vukusic, J. Stake, P. Andrekson, and H. Zirath, "Hydrodynamic 

simulations of uni-traveling-carrier photodiodes," IEEE J. Quantum Electron., vol. 43, pp. 1088-1094, 2007. 

[4] Biddut Banik, Josip Vukusic, Hans Hjelmgren, and Jan Stake, “Optimization of the UTC-PD Epitaxy for 

Photomixing at 340 GHz”, submitted to IEEE Electron Device Letters. 

135


P7-2 

DEVELOPMENT OF SUPERCONDUCTIVE PARALLEL JUNCTIONS ARRAYS 

FOR SUBMM-WAVE LOCAL OSCILLATOR APPLICATIONS 

F. Boussaha, B. Lecomte, F. Dauplay, M. Salez, L. Loukitch # , C. Chaumont * , A. Feret, 

J-M. Krieg, M. Chaubet + 

LERMA - Observatoire de Paris, 77 avenue Denfert-Rochereau, 75014 PARIS – France 

* GEPI – Pôle instrumental - Observatoire de Paris, 77 avenue Denfert-Rochereau, 75014 PARIS – France 

# Laboratoire de Mathématique, INSA de Rouen, B.P.8, 76131 Mont-Saint-Aignan cedex – France 

+ 

CNES - BP 2220, 18 avenue Edward Belin, 31401 Toulouse Cedex 4 – France 

We are developing Submillimiter-wave fully Integrated superconducting Receivers 

(SIRs) based on SIS mixer and SIS Multijunction operating as local oscillator. Multijunctionbased 

FFOs may be an interesting alternative to LJJ-based FFOs in SIRs, allowing wide LO 

tunability, wide impedance matching bandwidths, high design flexibility and control of 

technological parameters. We will present a numerical study of the Josephson 

electrodynamics, simulation and first DC and RF measurement results in this kind of device. 

136


P7-3 

Sideband Noise Screening of Multiplier-Based Sub-Millimeter LO Chains 

using a WR-10 Schottky Mixer 

Eric Bryerton 1 and Jeffrey Hesler 2 

The local oscillators for the ALMA band 9 receivers cover the frequency range from 610-712 

GHz. They are built using a YIG tuned oscillator as the fundamental source at 22.6-26.4 

GHz, then tripled and amplified in two ambient temperature modules before being multiplied 

again by a VDI (Virginia Diodes Inc.) cryogenic nonupler. Further descriptions of the LO 

chains and of their contributions to receiver noise are summarized in [1]. Recent receiver 

noise measurements using the ALMA band 9 SIS receiver show excess noise contributed by 

the LO at certain frequencies. Since the LO and the SIS receiver are developed and produced 

at different institutions on different continents, it is highly desirable to have the ability to 

diagnose and debug these noise problems before the LO is delivered. It is even more 

desirable to make these measurements without a cryogenic sub-millimeter receiver. Using a 

similar setup as Erickson [2] used to demonstrate SNR improvements from saturated 

amplifiers in LO chains, we use a VDI WR-10 single-ended Schottky mixer to measure the 

noise before the cryogenic multiplier, at 66-82 GHz. 

The 4-12 GHz IF from the Schottky mixer is amplified by approximately 50dB and measured 

by a spectrum analyzer. We see that the IF output measured when a Gunn oscillator is 

driving the WR-10 mixer is identical to the IF spectrum with no LO, i.e. only the IF noise is 

present. This shows that the Gunn is not adding any excess noise over that of the IF noise 

(and also that the mixer noise is dominated by the IF amplifiers in this case). With the 

ALMA LO in the same setup, we typically see a very small increase in noise (less than 

1K/uW), except for certain LO frequencies, where the measured IF spectrum is much higher 

for some portion of the IF (typically below 6 GHz). These noisy LO frequencies correspond 

precisely to the noisy LO frequencies seen with the ALMA band 9 SIS mixer at nine times 

the frequency. By debugging the problem with a room-temperature Schottky mixer at this 

much lower frequency, we were able to quickly identify a likely solution to mitigate the 

excess noise. For this specific case, we find that using narrower bandpass filters in the active 

multiplier chain reduces the excess noise. The LO unit is presently being shipped back to 

SRON for verification with the SIS mixer. At the conference poster session, we will show 

SIS measurements before and after, as well as Schottky measurements before and after, to 

show that this screening technique can be used to predict excess noise from an amplifiermultiplier 

based local oscillator chain. 

[1] E. Bryerton, M. Morgan, D. Thacker, and K. Saini, “Maximizing SNR in LO chains for ALMA singleended 

mixers,” in Proc. of the 18 th Intl. Symp. on Space THz Tech., Pasadena, CA, April 2007. 

[2] N. Erickson, “AM noise in drivers for frequency multiplied local oscillators,” in Proc. of the 15 th Intl. Symp. 

on Space THz Tech., Northampton, MA, April 2004. 

1 - National Radio Astronomy Observatory, Charlottesville, VA, USA 

2 - Virginia Diodes Inc., Charlottesville, VA, USA 

137


P7-4 

Frequency tunability and mode switching of quantum cascade lasers 

operating at 2.5 THz 

S. G. Pavlov, H.-W. Hübers, H. Richter, and A. D. Semenov 

German Aerospace Center (DLR), Rutherfordstr. 2, 12489 Berlin, Germany 

A. Tredicucci, R. Green, and L. Mahler 

NEST CNR-INFM and Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy 

H. E. Beere and D. A. Ritchie 

Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, 

UK 

Quantum cascade lasers (QCLs) are promising devices for local oscillators in terahertz 

heterodyne receivers. The lasing mechanism is based on intersubband transitions in the 

conduction band of heterostructures, most commonly made from GaAs/AlGaAs. A key issue 

for application in a heterodyne receiver is the frequency stability and tunability. Linear 

continuous frequency tuning is not straightforwardly obtained. We have investigated two 

QCLs. They are designed for an operation frequency at about 2.5 THz. One of the lasers has 

a Fabry-Perot resonator while the other laser is a distributed feedback (DFB) laser. The 

active medium of both lasers is based on a GaAs/AlGaAs superlattice. The design follows 

the so-called bound-to-continuum approach with a rather uniformly chirped superlattice and 

no marked distinction between the injection and lasing regions. Detailed high-resolution 

spectra of the laser emission as a function of temperature and current have been obtained by 

self-beating of the laser modes (only laser with Fabry-Perot resonator) as well as by mixing 

with the emission of a THz gas laser. We report on some spectral features, such as nonlinear 

dependences of the laser emission frequency on the current and singularities due to mode 

switching. The analysis shows frequency- and current-dependent nonlinearities of the 

frequency tuning for both lasers. The multi-mode QCL shows larger variations of the output 

power of a particular mode as well as larger frequency instabilities at the current values 

related to the mode switching. Less-expressed power variations have been found for the 

single mode DFB QCL. The results of the homodyne mixing indicate large variations of the 

effective refractive index in the active medium caused by the drive current. The implications 

for the use of the QCL as local oscillator in a heterodyne receiver will be discussed. 

138


P7-5 

Capabilities of GaN Schottky Multipliers for LO Power 

Generation at Millimeter-Wave Bands 

José V. Siles and Jesús Grajal 

Dep. de Señales, Sistemas y Radiocomunicaciones, Universidad Politécnica de Madrid, 

E.T.S.I. Telecomunicación, Ciudad Universitaria s/n, 28040 Madrid, Spain, 

e-mail: {jovi,jesus}@gmr.ssr.upm.es, tel: +34 91.336.73.58 

Abstract —Gallium Nitride (GaN) is a very promising material 

for either electronic and optoelectronic devices because of its high 

breakdown field, and peak and saturated electron drift velocity. 

Hence, despite of its lower electron mobility, GaN Schottky diodes 

might represent a good alternative to GaAs Schottky diodes for LO 

power generation at millimetre-wave bands due to a much better 

power handling capabilities. Results from numerical simulations 

for a 200 GHz doubler predict half the conversion efficiency for 

GaN Schottky multipliers when compared to GaAs Schottky 

multipliers. However, higher power handling capabilities, more 

than an order of magnitude higher than GaAs with same anode 

sizes, are predicted for GaN diodes. 

SUMMARY 

In the recent years, GaN has emerged as a very promising 

material for either electronic and optoelectronic devices mainly 

due to its wide direct bandgap (3.4 eV), which results in a high 

breakdown field, and its high peak and saturated electron drift 

velocity [1]. High breakdown voltage materials increase the 

power handling capabilities of the devices. Hence GaN 

Schottky diodes might represent a good alternative to GaAs 

Schottky diodes for LO power generation by frequency 

multiplication in a near future, when solid-states sources can 

provide larger amounts of LO power at frequencies around 

100-150 GHz. The potential capabilities of GaN Schottky 

diodes are not in the frame of the design of high frequency 

multiplier circuits, well within the submillimeter-wave region, 

but in the early stages of high-frequency multiplier chains 

where the excellent power handling capabilities of GaN can be 

exploited. However, GaN has the inconvenience of a lower 

electron mobility than GaAs, which results in an increase in the 

series resistance, and thereby, in lower efficiencies. 

The objective of this paper is to investigate the 

capabilities of GaN Schottky diodes for LO power generation 

at millimeter-wave and submillimeter-wave bands as an 

alternative to the widely used GaAs Schottky diodes. For this 

task, we have employed an Harmonic Balance numerical 

simulator that incorporates an accurate physics-based Drift- 

Diffusion model for GaN Schottky diodes. A similar simulator 

has demonstrated very good results for the analysis of GaAs 

Schottky diodes at millimetre and submillimeter-wave bands 

[2]. First, the electrical properties of both GaN and GaAs 

diodes will be compared, paying special attention to those with 

a major impact on the frequency multiplying process, such as 

the breakdown voltage, the electron mobilities, the nonlinear 

capacitance and the series resistance. Initial results (provided 

in Fig. 1) for a 200 GHz GaN Schottky doubler predict a 13 % 

efficiency, which is approximately half the efficiency obtained 

with a GaAs Schottky multiplier of similar characteristics, i.e. 

same doping (N D =1·10 17 cm -3 ) and anode size (36 μm 2 ). 

Nevertheless, the key point of the comparison lies in the input 

power at which the maximum efficiency is achieved for each 

case: ~10 mW for the GaAs case, and ~200 mW for the GaN 

case. For both cases, safe operation conditions, well far from 

breakdown, are guaranteed. Using such a high input power is 

only possible due to the excellent characteristics of GaN in 

terms of breakdown voltage, which represent the real 

advantage of this material over GaAs. Moreover, the enhanced 

power handling capabilities of GaN diodes will lead to 

simplified designs at the early multiplication stages of THz LO 

chains, allowing the use of either unbalanced configurations or 

2-diodes balanced configurations. Current designs with GaAs 

Schottky diodes employ at least 4-6 anodes balanced 

configurations for the low frequency multiplication stages [3]. 

Fig. 2: Comparative between a 200 GHz GaN Schottky doubler and a 

200 GHz GaAs Schottky doubler when a N D=1·10 17 cm -3 epilayer 

doping is considered. 

In the final manuscript, further details on the design and 

optimization of GaN Schottky multipliers, including the 

influence of different parameters such as the epilayer thickness 

and doping, will be provided. 

REFERENCES 

[1] F. Schwierz, “An electron mobility model for wurtzite GaN”, 

Solid-State Electronics, vol. 48, no. 6, pp. 889-895, June 2005. 

[2] J. Grajal, J.V. Siles, V. Krozer, E. Sbarra and B. Leone, 

“Performance Evaluation of Multiplication Chains up to THz 

Frequencies”, in Proc. 29 th Int. Conf. on Infrarred and Millimeterwaves 

& 12 th Int. Conf. on THz Electronics, September, 2004. 

[3] J. Ward, E. Schlecht, G. Chattopadhyay, A. Maestrini, J. Gill, F. 

Maiwald, H. Javadi and I. Mehdi, “ Capability of THz sources 

based on Schottky diode frequency multiplier chains”, IEEE MTT- 

S International Microwave Symposium Digest, pp.1587-1590, June 

2004. 

139


P7-6 

High Power Heterostructure Barrier Varactor Quintupler 

Sources for G-Band Operation 

Josip Vukusic, Tomas Bryllert and Jan Stake 

Department of Microtechnology and Nanoscience, Chalmers University of Technology; 

SE-41296 Göteborg, Sweden (e-mail: vukusic@chalmers.se). 

Abstract: There is a need for signal power in the G-band (140-220 GHz) for remote sensing of 

atmospheric gases and imaging applications, both as local oscillator and illumination source. Because 

of the inherent difficulty to generate power at these frequencies the output power from a lower 

frequency source can be multiplied to higher frequencies using a nonlinear device such as the 

heterostructure barrier varactor (HBV) diode. The advantage of the HBV is the symmetric/antisymmetric 

C-V/I-V that only allows odd multiplication, i.e x3, x5, x7 etc [1], which is beneficial 

leverage when targeting high frequencies. Also, the HBV operates bias free which simplifies 

connective circuitry resulting in a more compact and robust solution. Since the voltage handling 

capability of the HBV can be scaled by cascading the epitaxial growth this device is well suited for 

high power generation [2]. 

We aim at presenting design, fabrication and experimental results from state-of-the-art quintuplers 

(x5) operating at ~170 and ~200 GHz. The graph below shows measurement results from a 202 GHz 

quintupler with over 20 mW output power (limited by the available input power). 

Graph (a) Output power and efficiency from a 202 GHz HBV quintupler (b) frequency sweep with a constant 

input power for the quintupler 

References: 

[1] T. Bryllert, A. Olsen, J. Vukusic, T. A. Emadi, M. Ingvarson, J. Stake and D. Lippens, “11% efficiency 100 

GHz InP-based heterostructure barrier varactor quintupler” Electron. Lett., vol. 41, no. 3, pp. 131–132, Feb. 

3, 2005. 

[2] J. Vukusic, T. Bryllert, T. A. Emadi, M. Sadeghi, and J. Stake, "A 0.2-W heterostructure barrier varactor 

frequency tripler at 113 GHz," IEEE Electron Device Letters, vol. 28, pp. 340-342, May 2007. 

140


P7-7 

Cryogenic Phase Locking Loop System for Flux-Flow Oscillator 

A.V. Khudchenko 1,2 , V.P. Koshelets 1,2 , P.N. Dmitriev 1 , A.B. Ermakov 1,2 , O.M. Pylypenko 3 

and P.A. Yagoubov 2 , 

1 Institute of Radio Engineering and Electronics, Moscow, Russia 

2 SRON Netherlands Institute for Space Research, Groningen, the Netherlands 

3 

State Research Center of Superconducting Electronics "Iceberg", Kyiv, Ukraine 

ABSTRACT 

Recently a cryogenic phase detector (CPD) based on a superconductor-insulatorsuperconductor 

junction has been proposed and preliminary tested. A sinusoidal output signal 

of the CPD has been measured. Experimental data demonstrate that the CPD intrinsically 

could operate with an effective bandwidth more than 100 MHz. The CPD is initially intended 

for phase locking of the Flux-Flow Oscillator (FFO) in the Superconducting Integrated 

Receiver (SIR). A model describing coupling between a CPD and an FFO has been 

developed and experimentally verified. This model takes into account dependence of the 

CPD current on the input power and differential resistance of the CPD. Design of the 

Cryogenic Phase Locking Loop (CPLL) system for the SIR will be presented along with 

results of its implementation. An effective bandwidth of the CPLL system exceeds 25 MHz 

at an operation frequency of 400 MHz. This is considerably better than bandwidth of the 

room-temperature PLL system which is limited to 12 MHz by unavoidable delays in the long 

cables and semiconductor PLL system. The novel CPLL system synchronizes more than 50% 

of the FFO power for free-running FFO linewidth of about 10 MHz, compare to 20% in the 

case of regular PLL system. It results in improvement of the FFO spectral ratio and would 

expand the SIR operation range. Details of the phase noise measurements for the FFO phaselocked 

by the CPLL and results of development of the CPLL with the operation frequency 4 

GHz will be discussed. Practical application of the CPLL looks especially promising for 

development of the arrays of SIRs. 

The work was supported by the projects: RFBR 06-02-17206, ISTC 3174, NATO SfP 

981415, and Grant for Leading Scientific School 5408.2008.2 

Presentation: 

poster 

The corresponding author: Andrey V. Khudchenko 

Institute of Radio Engineering and Electronics 

Mokhovaya street 11, bldg 7; 

Moscow, 125 009, Russia 

Phone: +7-495-6293418 

Fax +7-495-6293678 

E-mail: 

Khudchenko@hitech.cplire.ru 

141


Fabrication of GaAs Schottky nano-diodes with T-Anodes 

for Submillimeter Wave mixers 

P8-1 

Cécile Jung 1+2 , Hui Wang 1 , Alain Maestrini 1+3 , Yong Jin 2 

1 Observatoire de Paris, LERMA, 61 Avenue de l’Observatoire, 75014 Paris 

2 CNRS, LPN, Route de Nozay, 91460 Marcoussis 

3 Université Pierre et Marie Curie-Paris6, LISIF, 75005 Paris 

Abstract– Schottky diodes are versatile components that can be used to build frequency agile 

THz sources or mixers working at room or cryogenic temperatures. Schottky diode 

technology is therefore strategic for several applications. 

In this context, we report on the design and fabrication of a T-gate anode structure for 

millimeter and submillimeter Schottky diodes. The process was developed using e-beam 

lithography and conventional epitaxial layers. Each step was optimized such as the time/dose 

exposure, metal thickness, annealing time/temperature…The T-gate anode uses multiple e- 

beam scans at different doses and a trilayer PMMA coating to define separately the air-bridge 

support, the air-bridge and the footprint. The major advantages of these T-Anode diodes are 

the reduced parasitic capacitance and resistance and very small realizable anode areas [1] [2]. 

Anti-parallel pairs of diodes with 1µm 2 anode area on 12µm thick GaAs substrate to be used 

in the same 330GHz sub-harmonic mixer block as in [3] are currently being fabricated. 

Monolithic circuits of 183GHz subharmonic mixers are also in the process of being 

fabricated. I(V) measurements have been performed on slightly bigger anodes leading to 

ideality factors η=1.1 and reverse saturation currents Is=2×10 -13 A. RF tests will be presented 

at the conference. 

This work is supported by the Centre National d’Études Spatiales, the Centre National de la 

Recherche Scientifique and ASTRIUM in Toulouse. 

a. T-Anode: 1,2µm x 0,8µm b. AntiParallel Diodes for a 330GHz mixer 

[1] I. Mehdi, S. C. Martin, R. J. Dengler, R. P. Smith and P. H. Siegel, “Fabrication and Performance of 

Planar Schottky Diodes with T-Gate-Like Anodes in 200-GHz Subharmonically Pumped Waveguide 

Mixers”, IEEE Microwave and Guided wave letters, Vol. 6, No. 1, January 1996. 

[2] S. Martin, B. Nakamura, A. Fung, P. Smith, J. Bruston, A. Maestrini, F. Maiwald, P. Siegel, E. 

Schlecht & I. Mehdi, “Fabrication of 200GHz to 2700GHz multipliers devices using GaAs and metal 

membranes”, proceedings of the IEEE MTT-S, Vol.3, pp. 1641-1644, Phoenix, Arizona, May 20-25, 

2001. 

[3] Bertrand Thomas, Alain Maestrini, and Gérard Beaudin, ”A Low-Noise Fixed-Tuned 300-360 GHz 

Sub-Harmonic Mixer using Planar Schottky Diodes”, IEEE Microwave and Wireless Component 

Letters, Vol. 15, Issue 12, pp. 865 – 867, December 2005. 

142


P8-2 

Towards a THz Sideband Separating Subharmonic Schottky Mixer 

Peter Sobis (1,2) , Jan Stake (1) and Anders Emrich (2) 

(1) Chalmers University of Technology 

Department of Microtechnology and Nanoscience 

SE-412 96, Göteborg, Sweden 

Email: peter.sobis@chalmers.se 

Email: jan.stake@chalmers.se 

(2) Omnisys Instruments AB 

Gruvgatan 8, SE-421 30, Västra Frölunda, Sweden 

Email: ps@omnisys.se 

Email: ae@omnisys.se 

Today GaAs Schottky mixers with state of the art planar submicron diodes are used for THzdetection 

up to 3 THz [1]. GaAs Schottky diodes can operate in room temperature which 

makes them good candidates for space applications and an interesting low cost alternative to 

low noise cryogenic SIS and HEB technologies. 

To our knowledge this is the first time a sideband separation mixer [2] using subharmonic 

Schottky mixers is presented. We will present the current status of the development of a 

novel sideband separating subharmonic reciever topology operating at 340 GHz, see Fig1. 

The design of a subharmonic mixer and the LO and RF waveguide hybrids will be presented 

followed by an account of measured S-parameters and mixer noise temperature. 

Fig1. Schematic of the sideband separation mixer (left) and modular assembly (right). 

[1] J.L. Hesler, T.W. Crowe, W.L. Bishop, R.M . Weikle, R.F. Bradley and Pan Shing-Kuo, 

“The development of planar Schottky diode waveguide mixers at submillimeter 

wavelengths”, IEEE MTT-S International Microwave Symposium Digest, vol 2, pp. 953-6, 

1997. 

[2] C. Risacher, V. Vassilev, V. Belitsky, A. Pavolotsky, “Design of a 345 GHz Sideband 

Separation SIS Mixer”, Proceedings of 3 rd ESA Workshop on Millimeter Wave Technology 

and Applications: Circuits, Systems and Measurement Techniques, 21-23 May 2003, Espoo, 

Finland 

143


P8-3 

Ultrawideband THz detector based on a zero-bias Schottky diode 


C. Sydlo 3 , O. Cojocari 1 , D. Schoenherr 4 , T. Goebel 2 , S. Jatta 2 , 

H.L. Hartnagel 2 and P. Meissner 2 

The work in the field of THz technology includes the emitters as well as the detectors. While 

a large number of approaches for THz emitters with increased power levels are evolving the 

detectors have show less progress in the last years. But essential for all THz work is the 

signal to noise ratio which also benefits from improved detectors. 

Nowadays, pyroelectric detectors and Golay cells are the most common room-temperature 

THz detectors available. They feature NEPs (noise-equivalent powers) down to 100 pW/Hz ½ , 

but their response time is quite large limiting the modulation to few tens Hertz. These 

detectors are quite bulky which inhibits flexible use. 

ACST has recently established a Schottky process for zero-bias detector diodes aiming at 

frequencies up to one THz and possibly higher. A specialised process allows forming of 

Schottky contacts with a very low barrier. This in turn provides low video resistances without 

the need for biasing. Due to the absence of bias, the noise of the detectors reduces to the 

Johnson limit of the video resistance and is free of 1/f noise. The presented devices exhibit a 

video resistance less than 10 kΩ at zero-bias and voltage noise of less than 15 nV/Hz ½ 

(measurements in full paper). Also the devices responsitivity shows values of more than 

15 A/W or 2500 V/W. This results in a NEP of less than 6 pW/Hz ½ combined with arbitrarily 

high modulation frequencies. The size of this detector with appendant amplifier is smaller 

than a matchbox (picture in full paper) allowing it to be placed and moved freely in any THz 

setup. However, it should be mentioned here, that this detector cannot compete yet with 

pyroelectric detectors or Golay cells at frequencies far beyond 1 THz. 

The main frequency limiting factors for the Schottky detectors are the RC time constant and 

the size of the diode. The diodes size should be small compared to the effective wavelength 

to diminish effects of the geometry. The RC time constant is formed by the total capacitance 

of the diode and the RF impedance of the antenna. In this work a planar logarithmic-spiral 

antenna has been deployed with circular polarisation to be independent of the polarisation 

angle in case of linear polarised THz radiation. Hence, the responsitivity of the detector 

reduces to half of its value due to the coupling of linear to circular polarisation. ´The 

impedance of the antenna is around 50 Ω and the total capacitance of the diode is around 3 fF 

resulting in a roll-off frequency of about 1 THz. First measurements up to 700 GHz have 

revealed no sign of a roll-off (measurements >1 THz in full paper). Further measurements 

will be carried out for the full paper. 

This work presents a very compact, highly sensitive and fast THz detector based on RF 

rectification by a Schottky diode. It suits ideally the needs for fast spectroscopy due to the 

very fast response time and high sensitivity. The developed process allows for larger 

integration into arrays for imaging applications. 

3 C. Sydlo and O. Cojocari are with the ACST GmbH, Darmstadt, Germany (sydlo@acst.de) 

4 D. Schoenherr , T. Goebel, S. Jatta, H.L. Hartnagel and P. Meissner are with the TU Darmstadt, Darmstadt, 

Germany 

144


P9-1 

Tolerance analysis of the ALMA band 10 front-end optics 

M. Candotti, Y. Uzawa, S. V. Shitov, Y. Fujii, K. Kaneko. 

National Astronomical Observatory of Japan 

2-21-1, Osawa, Mitaka, Tokyo, 

181-8588, 

JAPAN 

m.candotti@nao.ac.jp 

Abstract: The ALMA band 10 front-end optical configuration has been designed and 

theoretically assessed by means of accurate Physical Optics electromagnetic analysis. 

The design goal was to maximise the overall antenna efficiency and at the same time 

maintaining the optical structure complexity as simple as possible. 

In designing the mechanical structure holding the optical system parts, efforts have to 

be made in order to take into account possible deviations from the nominal design due 

to uncertainties in the mechanical fabrication and assembly process. 

Mechanical uncertainties can finally introduce uncertainties in the optical system 

performances, such as beam propagation direction and increase the aberrations of the 

beam pattern leading to loss of antenna efficiency. 

In order to characterise these uncertainties, tolerance analysis techniques can be used. 

There are different methods of estimating uncertainties, each of them combines various 

uncertainties to get an estimate of expected performance. In this study the worst case, 

root-sum-of-squares (RSS) and Monte Carlo analysis are applied to ray tracing model 

of the optical system. The Monte Carlo method is also applied to a full 3D GRASP 

model using physical optics simulations (2000) in order to predict the beam 

performance at the focal plane due to optical system elements misalignments. 

Assumptions are made for the numerical values of linear and angular absolute 

tolerances for each degree of freedom related to the assembling of the optical 

components. Within these assumptions the tolerance analysis is carried out stressing on 

the ALMA front-end specifications on loss of antenna efficiency and beam squint of 

the pair of orthogonally polarised main beams. 

It will be shown that within standard machined values of accuracy and assembling of 

the mechanical parts, the ALMA band 10 front-end specifications on loss of 

illumination efficiency and beam squint can be achieved for 98% of the simulated 

cases. This suggest that tighter mechanical precision or tuning parts should be 

considered for fully satisfying the ALMA project specifications. 

145


P9-2 

ALMA 183 GHz Water Vapor Radiometer 

A. Emrich, S.Andersson, Mats Wannerbratt 

Omnisys Instruments AB, Gruvgatan 8, 421 30 Göteborg, Sweden 

ABSTRACT 

The ALMA project hardware development is a challenge for many research groups and commercial companies. 

It is not common that state-of art performance must be combined with reliability and low cost in high frequency 

radiometer hardware. 

The ALMA Water Vapor Radiometer is a complete radiometer system consisting of quasi optics, calibration 

system, 183 GHz mixers and LNA’s, local oscillator system and filter-bank back-end. This is supported by an 

embedded computer, a high performance power system and an advanced thermal control of the complete system 

as well as key components. 

Omnisys is responsible for the design, implementation, 

verification and production of 60 WVR’s. The development 

part of the project is 12 months from kick-off to delivery of 

the first unit, including verification. The design will not be 

based on the demonstration models in any sense, not on 

component level, not on subsystem level and not on system 

level. The only common parts are that it is a switched system 

and a schottky mixer is used in the Front-End. 

The preliminary design indicates a mass of less than 25 kg 

and a power consumption of 25-30 W for the complete 

instrument, including features and functions such thermal 

stabilization, a chopper wheel and extensive monitoring and 

control. 

The radiometer system optimization as such will 

be presented. 

The design for production and design for 

reliability aspects will be presented. 

The signal chain from mixer to filter-bank 

design will be presented, including test results. 

The quasi optical design will be presented, 

including test results. 

146


P9-3 

147


P9-4 

Characterization of ALMA Calibration Targets 

A. Murk 1 , A. Duric 1 , F. Patt 2 

1 

University of Bern, Switzerland 

2 

European Southern Observatory, Germany 

The Atacama Large Millimeter Array (ALMA) has the challenging goal 

to achieve an absolute calibration accuracy better than 5% at 

frequencies between 30 - 950 GHz. This poses stringent requirements 

on its two black-body calibration targets, which will be operated 

at ambient and elevated temperatures. The targets need to have a 

high emissivity, which is equivalent to a low value of integrated 

scattering into all possible directions. Even more critical is the 

coherent backscatter of the target, since it will lead to frequency 

dependent standing waves between the target and the receiver. In 

addition the thermal properties of the target need to be well 

understood to ensure that its surface brightness temperature 

corresponds to the reading of the thermometers in its body under 

changing environmental conditions in the receiver cabin. 

We present detailed active backscatter measurements between 30- 

700GHz of different calibration target designs, which were obtained 

with a vector network analyzer. They were done at varying angles of 

incidence and polarizations in a quasi-optical setup with similar 

beam parameters as in the actual ALMA receivers. In addition, the 

integrated scattering was determined by passive radiometric 

measurements using a 90GHz and a 323GHz SIS receiver. In a third 

test setup the thermal gradients over the aperture of the elevated 

temperature target has been investigated with an IR camera. 

The initial ALMA prototype target under test consists of an array 

of sharp Aluminum pyramids covered with a thin casted layer of 

absorbing material. An alternative conical target design made out 

of an injection molded plastic absorber has been tested in 

parallel, as well as several off-the-shelf microwave absorbers. We 

will compare the test results of the different targets and discuss 

their advantages and disadvantages for the ALMA calibration system. 

148


P9-5 

Near field beam and cross-polarization pattern measurements of ALMA 

band 8 cartridges 

Masato Naruse 1,2 , Mamoru Kamikura 1,2 , Yutaro Sekimoto 1,2 , Tetsuya Ito 2 , Masahiro Sugimoto 2 , 

Yoshizo Iizuka 2 , Naohisa Satou 2 , Kazuyoshi Kumagai 2 

1 Department of Astronomy, School of Science, the University of Tokyo 

2 Advanced Technology Center and ALMA-J project office 

National Astronomical Observatory of Japan, National Institutes of Sciences 

To develop sensitive astronomical receivers, high precision measurements of beam pattern, cross-polarization 

pattern and polarization alignment are required. We have developed a vector beam measurement system covering 

385-500 GHz which measures the amplitude and phase at near field with wide dynamic range of 50dB. We measured 

corrugated horns, OMTs [1] (Orthomode Transducer), optics blocks at room temperature, also ALMA band 8 

cartridges [2] cooled in a cartridge-test-cryostat. The amplitude and phase at near field are transformed to far field, 

and compared to physical optics calculations with Grasp 9 and CORRUG as shown in Figure1. The co-polar beams 

were symmetrical, consistent with the simulations at 385, 415, 442, 470, 500GHz, and the calculated beam efficiency 

at the sub-reflector was greater than 92%. Side lobe was less than -30dB. The peak of cross polarization relative to co 

polarization was less than -20dB. 

In addition, to evaluate accuracy of measurements, we studied both effects of standing wave and stability of the 

amplitude and phase. The error of the far field was found to be less than 0.2dB between 0 and -20dB range. 

Relative Power [dB] 

0 

-10 

-20 

-30 

-40 

-50 

Symmetric Plane 

Simulation 

h-pol. 

v-pol. 

cross-pol. 

-60 

-7.5 -5 -2.5 0 2.5 5 7.5 

Angle [deg.] 

Figure 1: Beam pattern and cross polarization pattern of the optics block compared to simulation with Grasp9 at 500GHz. 

Reference 

[1] Kamikura et al. This conference 

[2] Sekimoto et al. This conference 

149


P9-6 

SIS Mixers for ALMA Band-10: Comparison of Epitaxial and Hybrid 

Circuits 

S. V. Shitov 1,2 , M. A. Bukovski 2 , A. V. Uvarov 2 , O. V. Koryukin 2 and Y. Uzawa 1 

1 National Astronomical Observatory of Japan, Mitaka, Japan 

2 Institute of Radio-Engineering and Electronics, Moscow, Russia 

To provide a basis for optimum choice of a SIS mixer for ALMA Band-10 (787- 

950 GHz), numerical simulations are performed based on properties of both the SIS 

junction and the possible design of its tuning/coupling circuit. The “traditional” Nb- 

AlOx-Nb and epitaxial NbN-AlN-NbN junctions are studied within either 

NbN(NbTiN)/Al or all-epitaxial NbN circuit. The calculations are based on Tucker’s 

theory, which simplest 3-port approximation, according to M. Feldman, fits the 

terahertz-range SIS mixers [1]. The extra noise associated with multiple Andreev 

reflection in NbN junctions [2] is also taken into account. The numerical simulations are 

finally fitted to the best experimental data available from the literature and to our own 

experiments. 

We conclude that, in spite the relatively leaky IV-curve, the performance of an 

epitaxial NbN junction embedded into a low-loss epitaxial NbN tuning circuit at about 

1 THz can be about the same as the performance of a high-quality Nb-AlOx-Nb junction 

embedded into a (relatively lossy) NbTiN/Al tuning circuit. The abovementioned 

conclusion is supported by the most recent experiments demonstrating Trx below 300 K 

(DSB) for the circuits made from the epitaxial NbN. A report on these experimental 

results is also planned for this conference. 

[1] M. Feldman, Private communication, 2005. 

[2] Y. Uzawa and Z. Wang, "Coherent multiple charge transfer in a superconducting 

NbN tunnel junction," Phys. Rev. Lett. 95, 017002 (2005). 

150


P11-1 

A semiconductor quantum dot for spectral sensitive detection of THz radiation 

R Davis 1 , S Pelling 1 , A. Tzalenchuk 2 and V. Antonov 1 

1 

Physics Department, Royal Holloway University of London, Egham, Surrey TW20 

0EX, UK 

2 National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, 

United Kingdom 

Spectral sensitive detection of THz radiation can be performed using a quantum dot 

formed in a two dimensional electron gas of GaAs/AlGaAs heterostructure. Different 

types of quantum dot sensors have been fabricated and studied. The most sensitive 

sensor, which is able to detect individual terahertz photons, consists of a quantum dot 

coupled to a metallic single electron transistor. This sensor however requires state of the 

art nanofabrication, delicate operation and temperatures below 1K. A more robust but 

less sensitive sensor is a quantum dot coupled to the point contact. It has reasonable 

nanofabrication demands and relaxed operation at T~1.5K. We compare two types of 

detectors, and suggest optimisation of the design aiming at improvement of quantum 

efficiency. 

151


P11-2 

Epitaxial ultra-thin NbN films grown on sapphire 

dedicated for superconducting mixers 

B. Guillet 1 , R. Espiau de Lamaestre 2 , P. Odier 3 , M.P. Chauvat 4 , P. Ruterana 4 , L. Méchin 1 , 

J.C. Villégier 5 

1 

GREYC, CNRS, ENSICAEN & Université Caen Basse Normandie, 6 Bd Maréchal Juin, 14050 Caen, France 

2 CEA-LETI, MINATEC, 17 Avenue des Martyrs, 38054 Grenoble Cedex 9, France 

3 Institut Néel, CNRS-Grenoble, 38042 Grenoble, France 

4 

SIFCOM, CNRS, ENSICAEN & Université Caen Basse Normandie, 6 Bd Maréchal Juin, 14050 Caen, France 

5 

CEA-DRFMC, MINATEC, Superconducting Device Group, 17 Avenue des Martyrs, 38054 Grenoble Cedex 9, 

France 

Sputtered niobium nitride (NbN) films have been considered as a good candidate for rapid 

single flux quantum electronics based on Josephson Junctions, for THz mixers based on Hot 

Electron Bolometric effect or for single photon detection applications (SSPD). Applications 

would benefit from higher quality films (epitaxial growth) with low concentration of defects, 

such as grain boundaries or twins, whose nature and concentration depend on the deposition 

conditions and the substrate. 

Efforts devoted to grow NbN aim at improving their critical temperature and critical current 

density, while keeping their thickness in the 3 to 5 nm range and Tc above 10 K, which 

insure a large bandwidth and large SNR detection at 4K. Choice of substrate is critical: for 

applications, MgO wafers and R-plane sapphire are usually considered as best choice. 

However, growing NbN on either M-plane or A-plane orientations of sapphire wafers, 3 inch 

in diameter, can help improving the film quality and fabrication yield. NbN thin films were 

grown by reactive DC magnetron sputtering at about 600°C and passivated by an AlN layer 

1.5 nm thick deposited in-situ at room temperature. Growth on M-plane is shown to be better 

than on other sapphire orientations, including R-plane. NbN layer critical temperature 

reaches 13.3 K. Their properties are uniform on the 3 inch wafer, for a film thickness of 4.4 

nm measured by X-ray reflectivity. We also obtained promising results on NbN growth on 

silicon wafers by using either an epitaxial YSZ/CeO 2 buffer layer grown ex-situ by PLD or a 

thin NbMgO buffer sputtered in-situ. Transport properties of NbN grown on those various 

substrates have been correlated to their crystallographic microstructure, examined by both 

symmetric and asymmetric X ray diffraction, high resolution transmission electron 

microscopy (HRTEM), spectroscopical ellipsometry, atomic force microscopy (AFM). These 

results will be presented in the framework of HEB and SSPD applications. Epitaxial 

multilayers NbN/MgO/NbN on M-plane sapphire have been also studied. Applications of 

these tunnel junctions as superconductor-insulator-superconductor (SIS) mixers have been 

considered. 

152


P11-3 

Terahertz emission from ZnSe nano-dot surface 

Shan He a,b , Xiaoshu Chen a , Xiaojun Wu a , Fuli Zhao a , Reng Wang c , Weizheng Fang c , Shuhong Hu c , Ning Dai c 

and *Gang Wang a 

a 

State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 

510275, P. R. China 

b 

School of Chemistry and Chemical Engineering,, 

Sun Yat-Sen University, Guangzhou 510275, P. R. China 

c 

National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of 

Sciences, Shanghai, P. R. China, 200083 

*email: stswangg@mail.sysu.edu.cn 

ABSTRACT 

As shown in Figure 1 (Fig. 1) ZnSe nano dots are fabricated on the surface of 

orientation ZnSe using femtosecond laser ablation technique. In this work, we studied the 

THz generation properties of the ZnSe nano-dots by electro-optic detection configuration. 

Three THz radiation mechanisms are observed in experiments: current surge effect (drift 

current), Photo Dember effect (diffusion current) and optical rectification. Compared with 

bulk ZnSe, the ZnSe nano dots generated much higher THz radiation power at the same 

experimental condition. When the ZnSe nano-dots covered 10% of total radiation surface, the 

radiation power is about two times stronger than that from the bulk bare sample (Fig. 2). 

Basicly, there are two kinds of mechanisms occur predominantly for the THz radiation 

of ZnSe nano dots: the first is lighting-rod effect that fields tend to concentrate at the tips of 

protrusions on surface; the second is local-plasmon effect that collective oscillation of 

electrons occurs in these protrusions. These two effects make the total surface electric field 

largely enhanced. In this study, we attribute the THz radiation enhancement phenomenon of 

ZnSe nano dots to the surface field enhancement effect. Using a simple hemispheriod model, 

we also obtained the enhancement factor of ZnSe nano dots. 

Keywords: THz radiation, surface field enhancement, surface nano-dot, ZnSe. 

Fig. 1. SEM micrograph of ZnSe nano-dots. 

Fig. 2. THz fluence as a function of pump 

fluence for nano-dot and bulk ZnSe samples. 

153


The response rate of a room temperature terahertz InGaAs-based bow-tie 

detector with broken symmetry 

P11-4 

I. Kašalynas 1,2 , D. Seliuta 1 , R. Simniškis 1 , V. Tamošiūnas 1 , V. Vaičikauskas 2 , and G. Valušis 1 

1 Semiconductor Physics Institute, A. Goštauto 11, LT-01108 Vilnius, Lithuania 

2 Institute of Physics, Savanoriu ave. 231, LT-02300 Vilnius, Lithuania 

Rapid evolution of THz electronics and its implementation in many areas require new concepts in 

developing compact broad-band THz sensors operating at room temperature. In addition, rapid 

response of the detectors would be an advantage indicating their versatility in recording circuits. 

In this communication, we present a study of transient properties of the InGaAs-based bow-tie 

diode with broken symmetry [1]. The principle of operation relies on non-uniform carrier heating in 

high-mobility electron gas [2]. The device schematically is shown in Fig. 1. The active part is an 

In 0.54 Ga 0.46 As layer of 534 nm thickness grown by MBE on InP (001) substrate. The electron 

concentration and mobility at room temperature are about 2×10 15 cm -3 and 13300 cm 2 /Vs, 

respectively. Ohmic contacts including one of bow-tie's leaf's metallization are made of Ti/Au/Pt 

compound evaporated on InGaAs layer and annealed. Etched and wired diodes were attached to a 

hemispherical silicon lens of 6 mm diameter from the substrate side. The detector was then mounted 

on a specially designed holder for free-space experiments. 

In this work the response rate of the bow-tie InGaAs detector is carefully investigated. A 500 MHz 

bandwidth oscilloscope is used for measurement. A 100 MHz bandwidth low-noise preamplifier is 

designed for easer signal record. The response rate of the detector connected in two different 

schemes is shown in Fig. 2. One can see that the rise time of the detector response is equal to 40 ns 

at both experimental setups. Note, that the pulse shape is not disturbed by preamplifier applied. An 

investigation of microwave source performances revealed that InGaAs-based bow-tie detector 

repeats exactly the pulse shape of the incident radiation. 

The performances of the detector are room temperature operation, passive detection scheme, the 

sensitivity of roughly 5 V/W below 1 THz, plateau type sensitivity vs. frequency characteristic, and 

the bandwidth greater then 10 MHz. 

Figure 1. Top view of the detector based on 

bow-tied InGaAs with broken symmetry. The 

size of the detector: length is 500 μm, width - 

100 μm, apex size – 12 μm, lengths of the 

'left' leaf - 50 μm and 'right' – 250 μm. 

Figure 2. An oscilloscope trace of the response of the detector 

connected in "50 ? resistive load" and "preamplifier" schemes. 

A synthesized signal generator (model HP 8673C) sources the 

detector with a 9.8 GHz frequency pulse of duration of 5 μs, 

repetition rate of 10 Hz, and rise time of 40 ns. 

[1] D. Seliuta, I. Kašalynas, V. Tamošiūnas, S. Balakauskas, Z. Martūnas, S. Ašmontas, G. Valušis, 

A. Lisauskas, H.G. Roskos, and K. Köhler, Silicon lens-coupled bow-tie InGaAs-based broad band terahertz 

sensor operating at room temperature, Electron. Lett. 42, 825 (2006). 

[2] D. Seliuta, E. Širmulis, V. Tamošiūnas, S. Balakauskas, S. Ašmontas, A. Sužiedėlis, J. Gradauskas, 

G. Valušis, A. Lisauskas, H. G. Roskos, and K. Köhler, Detection of terahertz/sub-terahertz radiation by 

asymmetrically-shaped 2DEG layers, Electron. Lett. 40, 631 (2004). 

154


P11-5 

The precise resonator measuring technique at MM and THz waves 

V.V. Parshin, M.Yu. Tretyakov, E.A. Serov. 

Institute of Applied Physics of Russian Academy of Sciences, 

46, Uljanova Str., Nizhniy Novgorod 603950, Russia. E-mail: parsh@appl.sci-nnov.ru 

The precise automatic spectrometer for condensed media and gases investigations on 

the base of high-Q open Fabry-Perot resonator (Q ~ 10 6 ) has been developed. Waveguidequasioptical 

supplying system for the resonator excitation is used. Six uniform modules are 

used for operation at frequency range 36 - 400 GHz. 

Backward wave oscillators (BWO), stabilized by a phase locked loop system, were 

used as radiation sources. The principle difference with to other known resonator technique is 

the use of the precise digital synthesizer with fast frequency scanning without loss of 

oscillation phase after switching for the resonator curve recording. The fast digital scanning 

permit to reduce greatly the recording time and thus to avoid the low frequency resonator 

drifts which is the main source of errors in the resonator curve width measurement. By 

averaging of aforementioned fast scan records we have got the record accuracy of resonator 

curve width measurement that is ± 25 Hz in comparison with ± 500 Hz for set-up with 

traditional synthesizers. For example, this accuracy corresponds to ~ 0.001 dB/km absorption 

sensitivity in gases. 

The original methodic and corresponding software for gases, liquids, solids, films and 

metals investigations have been developed and will be discussed. 

The achieved parameters permitted us to carry out the number of pioneer and current 

works: 

1. To study the losses mechanisms in the modern dielectrics with ultra low absorption 

(tanδ~10 -6 ) like CVD-Diamond, Silicon, wide gap semiconductors AIII - BV type at the 

temperatures from ambient up to 600C. The prognosis for these materials use in all THz 

range will be made. Particularly it was shown that there exists the principal possibility of 

absorption reduction in the modern CVD-Diamond at least by the order of magnitude. 

2. Water vapour absorption mainly defines the THz waves propagation in atmosphere. Broad 

band radiation absorption investigations in real atmosphere at temperatures -20 C + 30 C 

were made with the highest sensitivity that permits to study molecular line parameters and 

the atmospheric continuum absorption that are of great importance for advancing both 

atmosphere absorption models and theory of intermolecular interactions. 

3. Satellite antenna reflectivity investigations at cryogenic and ambient temperatures have 

been made. It was revealed that the metal coverings of composite carbon fibber antennas 

have inadmissibly high reflective losses which lead to the essential increase of noise 

temperature of high sensitive cryogenically cooled receivers. The real "frames" for metal 

reflectors cooling were indicated. 

155


P11-6 

A 585 GHz Quasi-Optical HEB Six-Port Reflectometer Based on an Annular 

Slot Antenna 

R. Percy, L. Liu, H. Xu, J. Schultz, A.W. Lichtenberger, R.M. Weikle, II 

Charles L. Brown Department of Electrical and Computer Engineering 

School of Engineering and Applied Science 


351 McCormick Road, Charlottesville, VA 22904-4743, U.S.A. 

Quasi-optical six-port reflectometers have become a topic of interest due to a lack of 

instrumentation for measuring scattering parameters (s-parameters) at terahertz frequencies. 

This paper presents a quasi-optical six-port reflectometer centered on 585 GHz using hotelectron 

bolometers (HEB). In this design as shown in figure 1, a ring-slot antenna couples a 

signal into the reflectometer creating a standing wave along a microstrip transmission line. The 

standing wave is then sampled by three evenly spaced HEBs. A polarization change caused by 

the shape of the transmission line allows the antenna to act as both the input and output ports 

(i.e. - a horizontally polarized signal is coupled into the device and re-radiated with vertical 

polarization). The reflectometer is expected to be sensitive to nanowatt power levels from 

570GHz to 640 GHz. 

The annular slot antenna and microstrip portion of the device have been independently 

fabricated and tested. This proof-of-concept test confirms that the polarization is switched 

within the device and provides a rough estimate of the power available for sampling. It was 

found that about 30 μW of power could be measured with an Ericson power meter. Simulations 

in conjunction with these data indicate that the HEBs should be capable of detecting 100’s of 

nanowatts. This requires each HEB to have approximate dimensions of 100nm by 200nm. This 

paper will present the six-port design and preliminary measurements. 

Figure 1: Design Schematic 

156


Solid-state non-stationary spectroscopy of 1-2.5 THz frequency range 

V.L.Vaks 1 , A.V.Illyuk 1 , A.N.Panin 1 , S.I.Pripolsin 1 , 

D.G. Paveliev 2 , Yu.I Koshurinov 2 

1 Institute for physics of microsructures RAS, Nizhny Novgorod, Russia 

2 N.I.Lobachevsky Nizhny Novgorod State University, Nizhny Novgorod, Russia 

P11-7 

The THz frequency range is attractive for spectroscopic investigations, since many strong 

molecule lines lie in this range. Absorption lines of light hydrides and vibration motions of many 

molecules lie here. It gives possibility of studying molecules (for example metalloorganic 

molecules) which absorption lines in other frequency ranges are very weak. 

The high precision, time-domain spectroscopy is unique method of analysis of 

multicomponent gas mixtures. This method has the sensitivity at level of 0,2 ppb, has high 

selectivity and possibility of measuring the investigated substances concentration. Besides, this 

method is simple to using. 

Nowadays there exist two approaches for THz pulse generation for tabletop devices. These 

are photoconductive switches illuminated by femtosecond laser pulses, and optical rectification 

using ultrashort laser pulses in nonlinear crystals. However the problem of frequency stability and 

bad resolution provides a fundamental limitation for these methods in high precision spectroscopy. 

This method is not suitable for high resolution spectroscopy. The second way is the classic 

approach to transfer the microwave methods to THz frequency range which is elaborated in 

IPM RAS. 

The spectrometer of 1-2.5 THz frequency range (with registration of a signal in time area) 

based on solid-state radiation sources is considered in this report. The necessity of development the 

new THz sources is concerned with the fact, that the present emission sources (such as back-wave 

oscillator (BWO)) are extremely expensive and have large sizes and quite short time of 

exploitation. They operate in the frequency range from 100 up to 1250 GHz and are base for 

creation of the synthesizers for precision measurements. 

Fig.1. The measurements of spectral 

distribution after multiplier 

Our approach consists of the application of the 

solid-state synthesizers of millimeter 

wavelength range based on e.g. Gunn 

generator (97.5-117 GHz) with PLL of 

reference generator and frequency multipliers 

on quantum semiconductor structures. Over 

the last several years, the superlattice 

structures are more effective for frequency 

transformation and detection, since the lower 

values of inertness and parasitic capacitances 

and presence of negative differential 

conductivity (till 1 THz) on the volt-ampere 

characteristic. The results of measurements 

of spectral distribution up to 4.9 THz after 

multiplier by using the Furie spectrometer on 

silicic helium bolometer are shown on Fig 1. 

The measurements of spectral line of 

methanol at 1062 GHz were carried out. 

This work was supported by RFBR (grants 07-03-91143, 06-08-01332-a, 03-02-17088), 

ISTC (project 3174 «Development and study of integrated receivers for operation frequencies 0.5 

– 1 THz»), SCIENCE FOR PEACE PROGRAMME (CBP.NR.SfPP 981415, “Integrated 

Spectrometers for Chemical Agents Detection and Atmosphere Monitoring”). 

157


P11-8 

NbN epitaxial SIS and SNS junctions on M-plane sapphire for THz detection 

J-C Villégier, R. Setzu, V. Michal, R. Espiau de Lamaëstre, P. Crozat 

Epitaxial NbN/MgO/NbN, NbN/MgO-AlN-MgO/NbN and NbN/TaN/NbN heterostructures 

have been grown by magnetron sputtering on M-plane sapphire in the form of Josephson 

junctions, SIS and SNS types (where N, i.e. the TaN barrier being near the metal-insulator 

transition) with large R N I C products at 4.2K. 

DC-sputtering of the Niobium nitride base-electrode at 600°C, observed [110] oriented, leads 

to Tc above 16K in 150 nm thick films, low dc resistivity of the films (


P12-1 

Design and Simulation of a Corrugated Polarizer and 

Waveguide-based OMT for a 129 GHz VLBI Receiver of KVN 

Moon-Hee Chung, Do-Heung Je, Seog-Tae Han, Changhoon Lee, and Duk-Gyoo Roh 

Radio Astronomy Division, Korea Astronomy & Space Science Institute 

In millimeter-wave VLBI systems, dual-circular polarization observations are 

generally performed. As the highest frequency band of KVN(Korean VLBI Network), 

a 129 GHz band receiver is being designed for prototype. To reduce the receiver noise 

temperature, it is necessary that passive components including polarizer and OMT are 

inserted into the cryogenically cooled dewar. Traditionally septum polarizers are used 

at lower frequencies like 22 and 43 GHz bands because of its simplicity. But this type 

polarizer has relatively narrow bandwidth and is difficult to be fabricated and 

assembled at higher frequencies. To overcome these drawbacks, corrugated phase 

shifter or polarizer integrated into waveguide-based OMT is expected to be employed 

for the 129 GHz VLBI receiver of KVN. Intensive simulations using commercially 

available tool like CST MWS are being carried out to optimize and predict the 

performance of the proposed polarizer and OMT. In this paper, the design and 

theoretically calculated performance of our prototype polarizer and OMT for the 129 

GHz band receiver will be presented. 

159


P12-2 

Simulation of THz Receiver Systems Using Hybrid Numerical Methods and 

Spectral Ray Tracing Technique 

Iraj Ehtezazi Alamdari 1 , Jian-Rong Gao 2 , Safieddin Safavi-Naeini 1 , 

1- University of Waterloo, Canada, iraj@maxwell.uwaterloo.ca, safavi@maxwell.uwaterloo.ca 

2- Technical University of Delft, SRON, The Netherlands, J.R.Gao@tudelft.nl 

In this paper the original Spectral Ray Tracing (SRT) technique is applied to calculate 

the radiation patterns of the antennas combined with the lens. The effects of internal 

reflection inside the closed volume of the lens are taken into account. SRT has been 

successfully applied to different kind of lens-antenna combinations and the results 

have good agreement with the measurement. In this paper we are comparing the results 

of SRT with commercial software and also we are applying the new hybrid method of 

SRT and MOM/FEM. 

In the hybrid method the field distribution around the near field of the antenna is 

calculated with numerical methods such as Method of Moments (MOM) and Finite 

Element Method (FEM) and then the effects of complex large structure surrounding 

the antenna on the radiation patterns of the antenna is calculated with SRT method. A 

second step of numerical calculation is necessary to evaluate the effects of the complex 

structure on the input impedance of the antenna. Because of the large size of the 

complex structure, MOM and FEM numerical methods are not efficient; on the other 

hand SRT can easily calculate the fields in complex large structures. 

The effect of the lens on input impedance of the antenna will be studied using the 

hybrid methods mentioned above. The internal reflections inside the lens will modify 

both the radiation patterns and the input impedance of the antenna. For the antenna 

design, two kinds of antennas will be studied for application in THz receiver systems: 

twin slot antenna and spiral antenna. The radiation patterns will be calculated with 

FEM & MOM along with the input impedance of the antennas for the near field of the 

antennas. 

We are using commercial software HFSS for Finite Element Method and FEKO for 

Method of Moments and different kinds of hybrid methods like MOM-GTD and 

MOM-PTD. The hybrid methods MOM-SRT and FEM-SRT are new methods in these 

aspects. 

160


P12-3 

Development of a 385-500 GHz Orthomode Transducer (OMT) 

Mamoru Kamikura 1,2 , Masato Naruse 1,2 , Shin’ichiro Asayama 2 , Naohisa Satou 2 , 

Wenlei Shan 3 , and Yutaro Sekimoto 1,2 

1 

Department of Astronomy, School of Science, the University of Tokyo 

2 

Advanced Technology Center and ALMA-J project office 

National Astronomical Observatory of Japan, National Institutes of Natural Sciences 

3 

Purple Mountain Observatory, Chinese Academy of Sciences 

We present the design and evaluations of an orthomode transducer (OMT) for ALMA Band 8 

(385-500 GHz) [1]. An OMT is a passive waveguide polarization diplexer that separates the signal 

received by a feed horn into its two orthogonal linearly-polarized components. Because of the 

difficulty of fabrication, an OMT has not been developed at frequencies above 320 GHz [2]. 

The design of the Band 8 OMT was similar to that of the ALMA Band 4 (125-163 GHz) 

OMT [3], which is based on an OMT with a Bφifot junction and a double ridged waveguide [4]. In 

submillimeter wavelengths mechanical tolerance becomes very severe, so we simulated effects of 

mechanical errors on the S-parameters of the OMT. The design is so robust that mechanical errors 

of 10 μm do not affect the performance of the OMT. 

The polarization isolation and the transmission loss of the Band 8 OMT were evaluated. The 

polarization isolation of the OMT measured to be larger than 25 dB with quasi-optical 

measurements. The transmission loss of the OMT at 4 K was determined to be 0.4 dB from noise 

measurements with a DSB mixer. 

References 

[1] Y. Sekimoto et al., this conference. 

[2] E.J. Wollack and W. Grammer, “Symmetric Waveguide Orthomode Junction,” 14 th ISSTT, pp. 

169-176, 2003. 

[3] S. Asayama et al., 2008, in preparation. 

[4] G. Moorey, R. Bolton, A. Dunning, R. Gough, H. Kanoniuk, and L. Reilly, “A 77-117 GHz 

Cryogenically Cooled Receiver for Radioastronomy,” Proc. of Workshop on the Applications of 

Radio Science, 2006. 

161


12-4 

Simulation and Scaled Model 

Measurement of Membrane-based Twin 

Slot Antennas at 0.6 THz and 2.5 THz 

W. Miao 1, 2 , F. Dauplay 1 , Y. Delorme 1 , G. Beaudin 1 , and S.C. Shi 2 . 

1 LERMA, Observatoire de Pairs, France 

2 Purple Mountain Observatory, NAOC, CAS, China 

Email: wmiao@mwlab.pmo.ac.cn 

Abstract – Planar twin slot antenna has been widely used in quasi optical hot 

electron bolometer (HEB) mixer design due to its good frequency and polarity 

selectivity and its symmetrical Gaussian beam. To reach the maximum RF coupling at 

the input terminal of mixer, the impedance of antenna and device should be well 

matched. Therefore, it is of particular importance to have a precise knowledge of the 

antenna’s impedance at the feed point in mixers design. 

In this paper, we’ll present the results of the simulation on the radiation pattern and 

input impedance of a membrane based twin slot antenna performed with “CST 

Microwave Studio” at 0.6 THz and 2.5 THz. A parabolic mirror instead of a silicon 

lens has been included in the quasi optical HEB mixer design and its effect to the 

integrated antenna has also been analyzed with “FEKO” by using the ray tracing 

approximation of physical optics. 

In order to validate the design results, a 200-times scaled model of the membrane 

based twin slot antenna was fabricated. The input impedance of the antenna was 

investigated with a three standards de-embedding technique, which extracts the 

scattering parameters of the antenna from the reflection coefficients measured at the IF 

port of the mixer when three different loads are connected at the twin slot antenna’s 

feed point. Measured results have been then compared with those simulated by “CST 

Microwave Studio”. 

162


P12-5 

Terahertz Attenuator Based on the Sub-wavelength Metal Structures 

Guozhong Zhao and Cunlin Zhang 

Department of Physics, Capital Normal University, Beijing 10037, P. R. China 

Key Lab of Terahertz Spectroscopy and Imaging in Beijing, P. R. China 

Key Lab of Terahertz Optoelectronics, Education Committee, P. R. China 

Email: guozhong-zhao@mail.cnu.edu.cn 

In recent years, terahertz (THz) optical components have been paid more and more attention. This 

is due to two reasons. One is from the technological needs of THz applications. Another is from the 

physics of THz devices. The surface plasma polaritons in metal has attracted much attention of scientists 

and engineers over the world. THz photonic components based on the sub-wavelength metal structures 

have been regarded as a potential candidate of THz devices. 

In this paper, we present a THz attenuator based on the sub-wavelength metal structures. The THz 

attenuator is designed and fabricated on a copper foil. We measured THz transmission of the attenuator 

by means of terahertz time domain spectroscopy. The experimental results show that the attenuator can 

have a good frequency selectivity which depends on the polarization of THz radiation. THz power can 

be attenuated continuously into any level at a certain THz frequency without changing the polarization 

and coherence of THz beam. Its attenuated frequency is designable by changing the size and shape of 

metal structures. The frequency selective transmission of the attenuator is determined experimentally. 

We believe that our results suggest a valuable THz component for THz application, in particular, for 

THz space instruments. 

163


164


Registered participants 

First name Last name Institution Country Email 

Shin'ichiro Asayama NAOJ Japan shinichiro.asayama@nao.ac.jp 

Damian Audley 

University of 

Cambridge 

UK 

audley@mrao.cam.ac.uk 

Biddut Banik 

Chalmers University 

of Technology 

Sweden biddut.banik@chalmers.se 

Tarun Bansal SRON Netherlands t.bansal@tudelft.nl 

Rami Barends 

Delft University of 

Technology 

Netherlands r.barends@tudelft.nl 

Jan Barkhof SRON Netherlands J.Barkhof@sron.nl 

Andrey Baryshev NOVA/SRON/RuG Netherlands a.m.baryshev@sron.nl 

Jochem Baselmans SRON Netherlands J.Baselmans@sron.nl 

Eric Becklin UCLA/USRA-SOFIA USA ebecklin@sofia.usra.edu 

Victor Belitsky 


of Technology, Sweden victor.belitsky@chalmers.se 

GARD 

Dominic Benford NASA / GSFC USA dominic.benford@gsfc.nasa.gov 

Bhushan Billade 


of Technology 

Sweden bhushan.billade@chalmers.se 

Raymond Blundell SAO USA rblundell@cfa.harvard.edu 

Albert Bos Astron Netherlands bos@astron.nl 

Faouzi Boussaha 

LERMA - 

Obesrvatoire de France faouzi.boussaha@obspm.fr 

Paris 

Jeffrey Bout 

University of 

Groningen 

Netherlands bout@astro.rug.nl 

Eric Bryerton NRAO USA ebryerto@nrao.edu 

Massimo Candotti NAOJ Japan m.candotti@nao.ac.jp 

Thomas Cecil University of Virginia USA twc7c@virginia.edu 

Goutam Chattopadhyay JPL/Caltech USA Goutam.Chattopadhyay@jpl.nasa.gov 

Xiaoshu Chen 

State Key 

Laboratory of 

Optoelectronic China chenxshu@hotmail.com 

Materials and 

Technologie 

Jean Yves Chenu IRAM France chenu@iram.fr 

Sergey Cherednichenko 


of Technology 

Sweden serguei@chalmers.se 

Moon-Hee Chung 

Korea Astronomy & 

South 

Space Science 

Korea 

Institute 

mhchung@kasi.re.kr 

Oleg Cojocari ACST GmbH Germany cojocari@acst.de 

Gerard Cornet SRON Netherlands g.cornet@sron.nl 

Ray Davis 

Royal Holloway 

Physics Dept 

UK 

r.p.davis@rhul.ac.uk 

Thijs de Graauw Leiden Univ./SRON Netherlands thijsdg@sron.rug.nl 

Leo de Jong SRON Netherlands L.de.jong@sron.nl 

Gert de Lange SRON Netherlands gert@sron.nl 

Vincent Desmaris 

GARD, Chalmers 

University 

Sweden Vincent.Desmaris@chalmers.se 

Pieter Dieleman SRON Netherlands P.Dieleman@sron.rug.nl 

Simon Doyle Cardiff University Wales, UK Simon.doyle@astro.cf.ac.uk 

Vladimir Drakinskiy 


of Technology 

Sweden vladimir.drakinskiy@chalmers.se 

Michael Edgar 


Technology 

USA rena@submm.caltech.edu 

165



Iraj 

Ehtezazi University of 

Alamdari Waterloo 

Canada iraj@maxwell.uwaterloo.ca 

Anders Emrich Omnisys Sweden ae@omnisys.se 

Akira Endo 

NAOJ / Univ. of 

Tokyo 

Japan akira.endo@nao.ac.jp 

Neal Erickson 

University of 

Massachusetts 

USA neal@astro.umass.edu 

Corinne Evesque IAS - CNRS France corinne.evesque@ias.fr 

Timothy Finn CAY Spain t.finn@oan.es 

Jian-Rong Gao SRON-TU Delft Netherlands j.r.gao@tudelft.nl 

Hans Golstein SRON Netherlands J.F.Golstein@sron.nl 

Gregory Goltsman 

Moscow State 

Pedagogical 

Russia goltsman@mspu-phys.ru 

University 

Paul Grimes Oxford University UK pxg@astro.ox.ac.uk 

Christopher Groppi University of Arizona USA cgroppi@as.arizona.edu 

Bruno Guillet GREYC CNRS France bguillet@greyc.ensicaen.fr 

Andre Gunst ASTRON Netherlands gunst@astron.nl 

Shan He 

State Key 

Laboratory of 

Optoelectronic China hs99zdy@163.com 

Materials and 

Technologie 

Abigail Hedden 

Harvard- 

Smithsonian Center USA ahedden@cfa.harvard.edu 

for Astrophysics 

Panu Helistö VTT Finland panu.helisto@vtt.fi 

Doug Henke 


of Technology, Sweden doug.henke@chalmers.se 

GARD 

Jeffrey Hesler VDI/UVA USA hesler@vadiodes.com 

Ronald Hesper 

University of 

Groningen / SRON 

Netherlands r.hesper@sron.nl 

Stefan Heyminck 

Max-Planck-Institut 

für Radioastronomie 

Germany heyminck@mpifr-bonn.mpg.de 

Richard Hills ALMA Chile rhills@alma.cl 

Rik Hortensius TU Delft Netherlands rikhortensius@hotmail.com 

Niels Hovenier TU Delft NL j.n.hovenier@tudelft.nl 

Heinz- 


Hübers 

Wilhelm 

Center 

Germany heinz-wilhelm.huebers@dlr.de 

Konstantin Ilin 

University of 

Karlsruhe 

Germany k.ilin@ims.uni-karlsruhe.de 

Hirofumi Inoue University of Tokyo Japan h-inoue@ioa.s.u-tokyo.ac.jp 

Herman Jacobs SRON Netherlands H.M.Jacobs@sron.nl 

Willem Jellema SRON Netherlands W.Jellema@sron.nl 

Ling Jiang University of Tokyo Japan ljiang@taurus.phys.s.u-tokyo.ac.jp 

Cécile Jung 

Observatoire de 

Paris 

France cecile.jung@obspm.fr 

Mamoru Kamikura NAOJ Japan kamikura.mamoru@nao.ac.jp 

Lin Kang Nanjing University China kanglin@nju.edu.cn 

Alexandre Karpov 


Technology 

USA karpov@submm.caltech.edu 

Irmantas Kašalynas 

Semiconductor 

Physics Institute 

Lithuania irmantak@ktl.mii.lt 

Pourya Khosropanah SRON Netherlands p.khosropanah@sron.nl 

Andrey Khudchenko 

Institute of Radioengineering 

and Russia Khudchenko@hitech.cplire.ru 

Electronics 

Reece Kind Glenair UK UK rkind@glenair.co.uk 

166



Phichet Kittara Mahidol University Thailand tepcy@mahidol.ac.th 

Teun Klapwijk 


Technology 

Netherlands T.M.Klapwijk@tudelft.nl 

Bernd Klein 

Max-Planck-Institut 

for Radioastronomy 

Germany bklein@MPIfR-Bonn.MPG.de 

Takafumi Kojima 

Osaka Prefecture 

University/NAOJ 

Japan s_kojima@p.s.osakafu-u.ac.jp 

Jacob Kooi Caltech USA kooi@caltech.edu 

Valery Koshelets 

Institute of Radio 

Engineering and Russia valery@hitech.cplire.ru 

Electronics 

Craig Kulesa University of Arizona USA ckulesa@as.arizona.edu 

Leonid Kuzmin Chalmers University Sweden leonid.kuzmin@mc2.chalmers.se 

Wouter Laauwen SRON Netherlands W.M.Laauwen@SRON.NL 

Igor Lapkin 


of Technology, Sweden lapkin@chalmer.se 

GARD 

Mark Lee 

Sandia National United 

Laboratories 

States 

mlee1@sandia.gov 

Roland Lefèvre LERMA France roland.lefevre@obspm.fr 

Mikko Leivo VTT - Finland Finland mikko.leivo@vtt.fi 

Jing Li 


Observatory,CAS 

China lijing@mail.pmo.ac.cn 

Chris Lodewijk 


Technology 

Netherlands c.f.j.lodewijk@tudelft.nl 

Arttu Luukanen 

Millimetre-wave 

Laboratory of Finland arttu.luukanen@vtt.fi 


Guohong Ma Shanghai University P. R. China ghma@staff.shu.edu.cn 

Alain Maestrini 


Paris, LERMA 

France alain.maestrini@obspm.fr 

Sylvain Mahieu IRAM France mahieu@iram.fr 

Doris Maier IRAM France maier@iram.fr 

Chris Martin Oberlin College US Chris.Martin@oberlin.edu 

Hiroshi Matsuo NAOJ Japan h.matsuo@nao.ac.jp 

Francois Mattiocco IRAM France mattiocc@iram.fr 

Imran Mehdi JPL USA imran.mehdi@jpl.nasa.gov 

Denis Meledin 


of Technology, Sweden denis.meledin@chalmers.se 

GARD 

Patricio Mena SRON Netherlands mena@rug.nl 

Wei Miao 

LERMA, 

Observatoire de France wei.miao@obspm.fr 

Paris 

David Miller Caltech USA davem@submm.caltech.edu 

Raquel Monje 


of Technology, Sweden raquel.monje@chalmers.se 

GARD 

Tetsuo Mori INFRARED LIMITED Japan tmori@infrared.co.jp 

Pat Morris Caltech/NHSC USA pmorris@ipac.caltech.edu 

Axel Murk University of Bern Switzerland murk@iap.unibe.ch 

Takao Nakagawa ISAS/JAXA Japan nakagawa@ir.isas.jaxa.jp 

Taku Nakajima 

Osaka Prefecture 

University 

Japan s_tac@p.s.osakafu-u.ac.jp 

Masato Naruse 

University of Tokyo, 

NAOJ 

Japan masato.naruse@nao.ac.jp 

Alessandro Navarrini 

INAF-Cagliari 

Astronomy 

Observatory 

Italy navarrin@ca.astro.it 

167



Omid Noroozian 


Technology 

USA omid@caltech.edu 

Olle Nyström 


of Technology 

Sweden olle.nystrom@chalmers.se 

Vladimir Parshin 

Institute of Applied 

Physics of RAS 

Russia parsh@appl.sci-nnov.ru 

Dmitry Pavelyev 

Nyzny Novgorod 

State University 

Russia pavelev@rf.unn.ru 

Sergey Pavlov 


Center 

Germany sergeij.pavlov@dlr.de 

Becca Percy University of Virginia USA rrp4d@virginia.edu 

Thomas G. Phillips Caltech USA rena@submm.caltech.edu 

Göran Pilbratt 

European Space 

Agency 

Netherlands gpilbratt@rssd.esa.int 

Patrick Pütz Universität zu Köln Germany puetz@ph1.uni-koeln.de 

Pekka Rantakari 

Millimetre Wave 

Laboratory of Finland pekka.rantakari@vtt.fi 


Paul Richards 

University of 

California, Berkeley 

USA richards@cosmology.berkeley.edu 

Heiko Richter 


Center 

Germany heiko.richter@dlr.de 

Erich Schlecht 

Jet Propulsion 

Laboratory 

USA Erich.Schlecht@jpl.nasa.gov 

Yutaro Sekimoto NAOJ Japan sekimoto.yutaro@nao.ac.jp 

José 

Centro Astronómico 

Serna 

Manuel 

de Yebes 

Spain jm.serna@oan.es 

Masumichi Seta 

University of 

Tsukuba 

Japan seta@physics.px.tsukuba.ac.jp 

Wenlei Shan 


Observatory, CAS 

China shawn@mwlab.pmo.ac.cn 

Sheng-Cai Shi 


Observatory, CAS 

China scshi@mail.pmo.ac.cn 

Shoichi Shiba 

The University of 

Tokyo 

Japan shiba@taurus.phys.s.u-tokyo.ac.jp 

Sergey Shitov NAOJ / IREE Russia sergey@hitech.cplire.ru 

Jose V. Siles 

Universidad 

Politecnica de Spain jovi@gmr.ssr.upm.es 

Madrid 

Andrey Smirnov 

Moscow State 

Pedagogical 

Russia s_andrey1981@yahoo.com 

University 

Peter Sobis 

Omnisys 

Instruments AB 

Sweden peter.sobis@chalmers.se 

Gordon Stacey Cornell University USA gjs12@cornell.edu 

Johannes Staguhn 

NASA/GSFC & Univ. 

of Maryland 

USA johannes.g.staguhn@nasa.gov 

Jan Stake Chalmers Sweden jan.stake@chalmers.se 

Nopporn Suttiwong 


Center 

Germany nopporn.suttiwong@dlr.de 

Cezary Sydlo ACST GmbH Germany sydlo@acst.de 

Gie Han Tan ESO Germany ghtan@eso.org 

David Teyssier ESAC Spain dteyssier@sciops.esa.int 

Bertrand Thomas 

Rutherford Appleton 

Laboratory 

UK 

b.thomas@rl.ac.uk 

Christopher Thomas 

University of 

Cambridge 

UK 

cnt22@cam.ac.uk 

Ross Thomson Glenair UK rthomson@glenair.co.uk 

Edward Tong 

Harvard- 

Smithsonian Center 

for Astrophysics 

USA etong@cfa.harvard.edu 

168



Jeanne Treuttel 

Observatory of Paris 

LERMA 

France jeanne.treuttel@obspm.fr 

John Tucker University of Illinois USA jrtucker@uiuc.edu 

Vladimir Vaks 

Institute for Physics 

of Microstructures Russia elena@ipm.sci-nnov.ru 

RAS 

Henk van der Linden SRON Netherlands H.H.van.der.Linden@sron.nl 

Elfi van Zeijl TU Delft Netherlands e.vanzeijl@student.tudelft.nl 

Anastasios Vayonakis Caltech USA avayona@submm.caltech.edu 

Vyacheslav Vdovin IAP RAS Russia vdovin@appl.sci-nnov.ru 

Jean- 

CEA-Grenoble, 

Villégier 

Claude 

DRFMC 

France jean-claude.villegier@cea.fr 

Josip Vukusic 


of Technology 

Sweden vukusic@chalmers.se 

Christopher Walker University of Arizona USA cwalker@as.arizona.edu 

Hui Wang 


Paris 

France hui.wang@obspm.fr 

Ming-Jye 

Wang 

Wang ASIAA Taiwan mingjye@asiaa.sinica.edu.tw 

Michael Wanke 

Sandia National 

Labs 

USA mcwanke@sandia.gov 

Mark Whale NUI Maynooth Ireland mark.r.whale@nuim.ie 

Wolfgang Wild SRON Netherlands w.wild@sron.rug.nl 

Satoshi Yamamoto University of Tokyo Japan yamamoto@phys.s.u-tokyo.ac.jp 

Stephen Yates SRON Netherlands s.yates@sron.nl 

Sigfrid Yngvesson 

University of 

Massachusetts 

USA yngvesson@ecs.umass.edu 

Atik Youssef CNRS-IAS France youssef.atik@ias.u-psud.fr 

Wen Zhang SRON Netherlands W.Zhang@sron.nl 

Cunlin Zhang 

Capital Normal 

University 

P. R. China cunlin_zhang@mail.cnu.edu.cn 

Guozhong Zhao 

Capital Normal 

University 

P. R. China guozhong-zhao@126.com 

169


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