36EMC <str<strong>on</strong>g>2007</str<strong>on</strong>g> ADVANCE PROGRAMEfficient Low-Frequency Modal Analysis of an AnechoicChamberLuis Nuno, N/A; Juan Balbastre, N/A; and Ignacio M<strong>on</strong>terde, PolytechnicUniversity of ValenciaAn efficient method to analyze the <strong>electromagnetic</strong> fields inside rectangularanechoic and semianechoic chambers from 30 to 100 MHz isshown. A modal expansi<strong>on</strong> is employed to develop the homogeneousand the inhomogeneous field. This is combined with circuital techniquesto compute the effect of the layers of ferrite and dielectrics inthe walls of the chamber. Several numerical results of the Free SpaceTransmissi<strong>on</strong> Loss (FSTL) of an anechoic chamber and the NormalizedSite Attenuati<strong>on</strong> (NSA) of a semianechoic chamber are provided.Calculati<strong>on</strong> of the H-Plane Pattern Influence to the SiteVSWR Result Using the M<strong>on</strong>te Carlo MethodWolfgang Müllner; and Alexander Kriz, — Austrian Research CentersGmbH - ARCIn this paper the error in site VSWR measurements caused by imperfectomnidirecti<strong>on</strong>al transmit antennas is investigated. On the basis of the H-plane pattern published by the manufacturer, the distributi<strong>on</strong> of the erroris calculated by means of the M<strong>on</strong>te Carlo Method. There are large differencesbetween the products from the Austrian Research Centers GmbHand from Schwarzbeck GmbH. In the frequency range from 1 to 18 GHz,the systematic error is less than 0.5 dB for the PODs and more than 2 dBfor the SBAs. The maximum deviati<strong>on</strong> is -0.5 dB / +1 dB and -4 dB / +2dB respectively. The c<strong>on</strong>tributi<strong>on</strong> to the measurement uncertainty, thevariance, is less than 0.1 dB and 1.4 dB respectively.Predicting Electromagnetic Coupling between HF, VHF, andUHF Antennas Using NECWilliam Duff, SEMTASThere are many applicati<strong>on</strong>s where it is desirable for transmit andreceive antennas operating in adjacent frequency bands (e.g. HF,VHF, and UHF) to be co-located. In order to avoid EMI, it is necessaryto provide adequate isolati<strong>on</strong> between the co-located antennas.This paper presents the results obtained by using NEC to calculatethe coupling for different geometric arrangements of the antennas.EMI Analysis of a GSM 900 MHz Antenna for a Large WindTurbine Hub with Method-of-MomentsBastian Lewke, Technische Universität München; Florian Krug, duringresearch work: GE Global Research; and Josef Kindersberger, TechnischeUniversität MünchenElectro-magnetic fields resulting from a GSM transmitter mounted <strong>on</strong>a large wind turbine will be analyzed. This cellular system operates asa novel communicati<strong>on</strong>s back-up in case the standard communicati<strong>on</strong>between the operator and hub c<strong>on</strong>trol systems is interrupted. Themethod-of-moments is used to analytically describe the electro-magneticfields caused by a GSM 900 MHz transmitter mounted <strong>on</strong> the hubof a wind turbine. Using a commercial simulati<strong>on</strong> tool, the <strong>electromagnetic</strong>field distributi<strong>on</strong> will be analyzed to determine an optimizedwireless communicati<strong>on</strong> link to a base stati<strong>on</strong>. Different transmitterpositi<strong>on</strong>s are evaluated based <strong>on</strong> their radiati<strong>on</strong> patterns. Scattering anddiffracti<strong>on</strong> by the turbine’s rotati<strong>on</strong> is taken into account.Ultra-Wideband Printed Circuit Antenna in Coplanar TechnologyHarry Lam; and Jens Bornemann, — University of VictoriaA printed circuit antenna in coplanar waveguide technology forultra-wideband measurements is introduced. The frequency of operati<strong>on</strong>is 4 to 12 GHz with the VSWR less than 2 except for a verysmall band around 5.3 GHz. Omni-directi<strong>on</strong>al characteristics in verticalpolarizati<strong>on</strong> are dem<strong>on</strong>strated at two selected frequencies. Theanalysis method is verified against previous measurements.COMPUTATIONAL ELECTROMAGNETIC MODELING IAn Extended-Hybrid-Method: A Combinati<strong>on</strong> of MoM, GMTand UTDStefan Balling; Dirk Plettemeier; and Karl-Heinz G<strong>on</strong>schorek, —Technische Universität DresdenA new Extended-Hybrid-Method (EHM) is proposed. It unites thewell known Method of Moments (MoM), the Generalized MultipoleTechnique (GMT), and the Uniform Geometrical Theory ofDiffracti<strong>on</strong> (UTD). With this EHM, it is possible to calculate specialarrangements more efficiently in comparis<strong>on</strong> to other standardcomputati<strong>on</strong> methods. This is achieved by using the advantages ofeach method. As an example, the EHM is used to examine an antennanext to a human head model and a metallic door.Razor Blade Functi<strong>on</strong>s in the PEEC MethodVolker Vahrenholt, Institute of Electromagnetic Theory; Heinz-DietrichBrüns, Technical University Hamburg-Harburg; and Hermann Singer,Technical University Hamburg-HarburgModern electrical devices are of particular c<strong>on</strong>cern in terms of <strong>electromagnetic</strong><strong>compatibility</strong> (EMC). Various numerical methods havebeen developed for EMC problems. One of those numerical methodsis the partial element equivalent circuit (PEEC) approach, which wasbasically developed in order to combine electrical circuits and <strong>electromagnetic</strong>problems, because a circuit formulati<strong>on</strong> of the electricaldevices can be achieved. The standard PEEC formulati<strong>on</strong> uses theGalerkin method in order to transform the EFIE into an equati<strong>on</strong> system,and rectangular source functi<strong>on</strong>s are taken in order to apply analyticalintegrati<strong>on</strong> formulas. In this paper, the new possibility ofapplying razor blade functi<strong>on</strong>s is presented in order to allow the applicati<strong>on</strong>of numerical integrati<strong>on</strong> within nearly the same computati<strong>on</strong>time as the analytical way. In additi<strong>on</strong>, a higher accuracy is achieved,because Green’s functi<strong>on</strong> can totally be integrated including the retardati<strong>on</strong>term. Examples are presented within this paper in order toshow that a good agreement is obtained between the Galerkin PEEC,the PEEC based <strong>on</strong> razor blade testing, and a Method of Momentssimulati<strong>on</strong> (MoM), which is applied for validati<strong>on</strong>.Extended MagPEEC Model Including Dispersive MediumXiao Zhang; Haibo L<strong>on</strong>g; Wenhua Chen; Yaqin Chen; and Zhenghe Feng,— Department of Electr<strong>on</strong>ic Engineering, Tsinghua UniversityThis paper presents an extended MagPEEC modeling technique usedto simulate arbitrary three-dimensi<strong>on</strong>al structures including a dispersivemedia. It remains the high precisi<strong>on</strong> of modeling with anacceptable increase in total computati<strong>on</strong>al complexity. This approachis verified by modeling a coaxial transmissi<strong>on</strong> line and magneticallyenhanced RFIC inductors up to multi-GHz, including the significantfrequency dependence of the permeability of the magnetic core inthis band. The efficiency of the proposed method is validated bycomparing its results with some commercial EM simulating software.The Error Reduced ADI-CPML Method for EMC Simulati<strong>on</strong>Iftikhar Ahmed; and Erping Li, — Institute of High PerformanceComputingIn this paper, c<strong>on</strong>voluti<strong>on</strong>al perfectly matched layer (CPML) is developedfor the recently proposed error reduced (ER) ADI-FDTD©<str<strong>on</strong>g>2007</str<strong>on</strong>g> IEEE www.emc<str<strong>on</strong>g>2007</str<strong>on</strong>g>.org
EMC <str<strong>on</strong>g>2007</str<strong>on</strong>g> ADVANCE PROGRAM 37method to solve <strong>electromagnetic</strong> <strong>compatibility</strong> problems efficiently.Its numerical results are examined and compared with the c<strong>on</strong>venti<strong>on</strong>alADI-CPML method. It is found that for a CFL number equalto 5, the reflecti<strong>on</strong> error of the ERADI- CPML is approximately 12dB better than the c<strong>on</strong>venti<strong>on</strong>al ADI-CPML method.Efficient 3D Simulati<strong>on</strong> of Thin C<strong>on</strong>ducting Layers ofArbitrary ThicknessGöran Erikss<strong>on</strong>, Saab Communicati<strong>on</strong>, Saab ABIn this paper it is dem<strong>on</strong>strated how a class of relatively complexEMC simulati<strong>on</strong>s can be performed at a low cost, both in terms oftime and m<strong>on</strong>ey. Using a symmetric, two-way boundary c<strong>on</strong>diti<strong>on</strong>formulati<strong>on</strong>, shielding metal layers can be included in a global <strong>electromagnetic</strong>simulati<strong>on</strong>, without the need to resolve in detail theinterior of the layer. This formulati<strong>on</strong>, which has been previouslyused for some specific microwave and EMC problems, has no restricti<strong>on</strong>s<strong>on</strong> the ratio of layer thickness to the skin depth. It is implementedin a commercial finite element method (FEM) solverinstalled <strong>on</strong> a standard PC, and no source-code programming isrequired. The method is validated and its usefulness dem<strong>on</strong>stratedby applying it to a number of 3D examples of general EMC relevance.Wide-Band Hybrid MM-PO Computati<strong>on</strong>al ElectromagneticsTechnique Using [Z] Matrix Interpolati<strong>on</strong> and AdaptiveFrequency SamplingAndrzej Karwowski; and Artur Noga, — Silesian University of TechnologyIn this paper, we present a highly efficient computati<strong>on</strong>al <strong>electromagnetic</strong>stechnique for wide-band analysis of antennas radiating inthe presence of electrically large c<strong>on</strong>ducting bodies (platforms). Thetechnique is based up<strong>on</strong> the well known Moment Method–PhysicalOptics (MM-PO) hybrid formulati<strong>on</strong> combined with the impedancematrix interpolati<strong>on</strong> and a dynamic adaptive frequency sampling ofthe desired observable. Numerical examples are given to dem<strong>on</strong>stratec<strong>on</strong>siderable savings in both computer memory and CPU timeoffered by the proposed approach.COMPUTATIONAL ELECTROMAGNETIC MODELING IIFast FDTD Simulati<strong>on</strong> Using Laguerre Polynomials in MNAFrameworkKrishna Srinivasan; Ege Engin; and Madhavan Swaminathan, — GeorgiaInstitute of TechnologyIn this paper, a fast transient simulati<strong>on</strong> scheme using Laguerre polynomials,called Laguerre-MNA, has been developed for FDTD andcircuit simulati<strong>on</strong>. Compani<strong>on</strong> models for the Yee cells and circuitcomp<strong>on</strong>ents have been derived, permitting the use of MNA analysisto perform FDTD/transient circuit simulati<strong>on</strong>s using the Laguerremethod. Compani<strong>on</strong> models help simplify the matrix setup andreduce the matrix dimensi<strong>on</strong> that needs to be solved without employingl<strong>on</strong>g cumbersome equati<strong>on</strong>s. The FDTD simulati<strong>on</strong> usingLaguerre polynomials is unc<strong>on</strong>diti<strong>on</strong>ally stable and has shown to bemuch faster than the c<strong>on</strong>venti<strong>on</strong>al FDTD scheme. Prior work <strong>on</strong> transient<strong>electromagnetic</strong> simulati<strong>on</strong>s using Laguerre polynomials has adrawback of being able to simulate <strong>on</strong>ly for a certain time-durati<strong>on</strong>.A memory/time efficient soluti<strong>on</strong> has been proposed by which simulati<strong>on</strong>can be d<strong>on</strong>e for all time.Applicati<strong>on</strong> of a Hierarchical SVD/ACA Compressi<strong>on</strong>Technique to Near-Field Calculati<strong>on</strong>s of M<strong>on</strong>opole AntennasMiguel Astner, TU Hamburg-Harburg; Heinz-D. Brüns, TU Hamburg-Harburg; Guido Bürger, HVB Systems GmbH; and Hermann Singer, TUHamburg-HarburgThis paper describes the c<strong>on</strong>cept of hierarchical matrices and theapplicati<strong>on</strong> to near-field calculati<strong>on</strong>s of voltage or power drivenantennas. The hierarchical matrix structure is based up<strong>on</strong> a binarypartiti<strong>on</strong> of the structure to be analyzed, where blocks of the matrixcan be represented as full matrices or R(k)-matrices, the latter yieldinga data reduced representati<strong>on</strong> of the initial block. It has beenfound that the applicati<strong>on</strong> of <strong>on</strong>ly the adaptive cross-approximati<strong>on</strong>(ACA) matrix reducti<strong>on</strong> technique gave bad results in many practical3D cases and failed to predict the physical current distributi<strong>on</strong>. Theway out of this dilemma is to combine ACA with singular valuedecompositi<strong>on</strong> (SVD), yielding reliable results again. The new compressi<strong>on</strong>scheme turns out to be efficient and stable, and will bedescribed in detail. By means of examples, the validity of theapproach is dem<strong>on</strong>strated, where especially near-field investigati<strong>on</strong>sare carried out.Efficient Evaluati<strong>on</strong> of Equivalent-Principle Sources inMoM-FDTD Hybrid Method by Employing SpatialInterpolati<strong>on</strong> and Adaptive SamplingAndrzej Karwowski; and Tomasz Topa, — Silesian University ofTechnologyThe MoM-FDTD hybrid approach requires the informati<strong>on</strong> to beexchanged back and forth between the MoM-regi<strong>on</strong>s and the FDTDregi<strong>on</strong>scoupled through the Huygens’ surfaces. For electrically largestructures, evaluati<strong>on</strong> of the electric and magnetic field comp<strong>on</strong>entsand the related equivalence-principle sources <strong>on</strong> the Huygens’ surfacescan represent a significant (even dominant) fracti<strong>on</strong> of the totalsoluti<strong>on</strong> time required for the problem. In this paper, we dem<strong>on</strong>stratea possibility of increasing the computati<strong>on</strong>al efficiency of theMoM-FDTD hybrid method by employing a spatial interpolati<strong>on</strong>combined with adaptive sampling in calculating the electric andmagnetic field comp<strong>on</strong>ents and the effective sources <strong>on</strong> the Huygens’surfaces. Numerical examples show that the proposed approach offersa c<strong>on</strong>siderable CPU time saving.Near Field - Far Field C<strong>on</strong>versi<strong>on</strong> Based <strong>on</strong> GeneticAlgorithm for Predicting Radiati<strong>on</strong> from PCBsH<strong>on</strong>gmei Fan; and Franz Schlagenhaufer, — The University of WesternAustraliaA near field-far field c<strong>on</strong>versi<strong>on</strong> based <strong>on</strong> a genetic algorithm hasbeen performed for a printed circuit board with a ground plane. Arobust procedure for a pre-selecti<strong>on</strong> of dipole moments has beenintroduced. Important aspects of setting up the c<strong>on</strong>versi<strong>on</strong> problem,such as the number of equivalent dipoles and choice of matchingpoints, have been addressed.Use of Genetic Algorithms to Solve Inverse ScatteringProblemsDirk Plettemeier, Technische Universität Dresden; Stefan Balling, TechnischeUniversität Dresden; Diemo Landmann, N/A; and Karl-Heinz G<strong>on</strong>schorek,Technische Universität DresdenThe inverse scattering problem described in this paper is part of thequasi-tomographic Comet Nucleus Sounding Experiment byRadiowave Propagati<strong>on</strong> (CONSERT) of the comet-missi<strong>on</strong> Rosetta.This part of the experiment is based <strong>on</strong> the utilizati<strong>on</strong> of radiati<strong>on</strong>coupling effects between the CONSERT antenna system <strong>on</strong> theRosetta-Lander and the subsurface structure of the comet nucleus inthe vicinity of the Lander. The scientific aim of this part of CON-SERT is the rec<strong>on</strong>structi<strong>on</strong> of the subsurface structure at the landingsite, especially in view of the still open questi<strong>on</strong>: “Is a comet nucleussurround by a dust layer or not?” To solve this inverse scattering©<str<strong>on</strong>g>2007</str<strong>on</strong>g> IEEE www.emc<str<strong>on</strong>g>2007</str<strong>on</strong>g>.org