Introducing HFSS 12.0 - Ansys

Introducing HFSS 

Version 12 

Ansoft Product 

Management 

© 2008 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary

HFSS 12.0 

…high-performance …achieve …ANSYS “HFSS 12.0 is a follows a breakthrough dramatic through computing reduction in high-frequency on its enhancement, 

in commitment development 

electromagnetic to field 

domain time deliver first time, and engineers technology decomposition…simulate costs are while able with to at solve the unequalled vast same electromagnetic time and depth realizing design and field at a 

scale increased unparalleled problems and with speed reliability speed, breadth… efficiency never and… and before accuracy. possible. “ 

simulation,” said Zol Cendes, chief technology officer at Ansoft. “For the 


HFSS 12: New Features 

Integration with ANSYS 

DesignXplorer 

Adjoint Method Based Derivatives 

New Solver Technology 

Improved GUI and Modeler 

New Meshing 

Technology 

0.0001 

0.00001 

New Element 

Technologies 

© 2008 ANSYS, Inc. All rights reserved. 3 ANSYS, Inc. Proprietary 

Delta S 

0.1 

0.01 

0.001 

Fi… 

0 10000

New Solver Technology 

Domain Decomposition 


Simulating Large 

•F-35 Joint Strike Fighter: UHF blade antenna @ 350 MHz 

•L = 18.6 , V = 806 3 


Domain Decomposition 

• Distributed memory parallel 

solver technique 

• Distributes mesh subdomains 

to network of 

processors 

• Significantly increases 

simulation capacity 

• Highly scalable to large 

numbers of processors 

• Automatic generation of 

domains by mesh partitioning 

– User friendly 

– Load balance 

• Hybrid iterative & direct solver 

– Multi-frontal direct solver for 

each sub-domain 

– Sub-domains exchange 

information iteratively via 

Robin’s transmission 

conditions (RTC) 

Distributes mesh sub-domains 

to networked processors and memory 


18X Speed-up with 15 Domains 

Number of 

domains Speed-up 

1 1.00 

2 2.60 

3 3.84 

4 5.19 

5 6.69 

6 8.35 

7 8.78 

8 10.67 

9 11.44 

10 13.21 

11 12.51 

12 12.89 

13 15.23 

14 14.10 

15 17.71 

18 

17 

16 

15 

14 

13 

12 

11 

10 

9 

8 

7 

6 

5 

4 

3 

2 

1 

Speed-up 

Superlinear performance! 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 

Speed-up 


Results and Accuracy 

• Consistent results between domain 

decomposition and direct solver 


Humvee with Patch Antennas 

• Two L-band patch antennas 

located on roof of Humvee 

– Fed using TM20 mode to excite 

monopole far-field pattern 

• Bounding airbox is 12.5 x 22 x 

8 or 2200 3 

6 domains Domain Solver 

Total Memory 4.5 GB 

Average Memory 0.75 GB 

1 st order basis functions. Performed 

8 passes to reach S = 0.02 


WLAN Access Point and Printer 

• Wireless printer and router in typical office 

environment 

– 2.44 GHz solution frequency 

• Room size is 25 x 25 x 22 or 13750 3 

• Solved on 16 core AMD Opteron 

workstation 

• Printer-to-router coupling: -57 dB 

15 domains Domain Solver 

Tetrahedra 846k 

Total Memory 32 GB 

Average Memory 2.0 GB 


Domain Decomposition Example 

Antenna Integration on Spacecraft 


Antenna Element Design 

• Operating criteria 

– 3-4 GHz frequency band 

– 50 input impedance 

• Axial mode helix selected as antenna 

– Endfire radiation with moderate gain 

– Right-hand circular polarization 

– Wide bandwidth 

– Simple feed 

– High radiation efficiency 

• Orthogonal support dielectric along helix 

• Coax probe feed extends above antenna 

ground plane 

• Simulation with direct solver 

– 200k unknowns in 1.2 GB 


Finite Array Model 

• 7-element array model with 

finite ground plane 

– Includes edge effects 

– Includes mutual coupling 

between elements 

Far-field Pattern for 

Broadside Beam 

Fields with All Element Excited 

Far-field Pattern for 

Broadside Beam 


Installed Array on Spacecraft 

• Good correlation with 

isolated array patterns 

• L = 78 λ, V = 31,000 λ 3 

– 25M unknowns across 35 

cores 

• Recalibrate your expectations! 


New Meshing Technology 


New Meshing Technology 

Surface Mesh 

Volume Mesh 

HFSS 11 

(bottom up algorithm) 

model 

Geometric healing or repair 

(For model defects) 

Surface mesh generation 

Volume mesh generation 

Volume Mesh 

Surface Mesh 

HFSS 12 

(top down algorithm) 

model 

Volume mesh generation 

Adapt mesh to conform to geometry 

Conformal surface mesh generation 


TAU Mesher 

• Mesh a higher percentage 

• Effective on imported geometries 

• Higher mesh quality 

• fewer total elements 

• smoother element transition 

• Automatically healing and repair. 


v11 

v12

New Element Technology 

Curvilinear Elements 


Curvilinear Elements 

• Most accurate solution to fields on 

curved structures 

• Mesh adapted about curved or 

true surfaces 

• Element matrices computed using 

the curved boundaries 

• Reduces solution time and RAM 

usage 

– A smaller, coarser mesh 

achieves equivalent accuracy 

Rectilinear mesh element Curvilinear mesh element 

10 cm radius PEC sphere 

solved from 0.040 - 2 GHz 

Red – HFSS 

Blue – Analytic Curve 


SLAC Beam Former 

Ansoft LLC XY Plot 4 

truesurfaces_longer 

0 

Return Loss TM01 mode (dB) 

-5 

-10 

-15 

-20 

-25 

-30 

-35 

E-field along Z 

Measurements 

11,428.4 +- 0.5 MHz 

-40 

11426.0 11426.5 11427.0 11427.5 11428.0 

Freq [MHz] 

11428.5 11429.0 11429.5 11430.0 


Curve Info 

dB(S(WavePort1:3,WavePort1:3)) 

Setup1 : Sw eep1 

SA='22.5deg'

Resonator with Concentric 

Spherical Dielectrics 

• Fewer curvilinear elements yield 

same accuracy as rectilinear 

– 88% fewer tetrahedra 

– Runs 16X faster 

I Wolff, “A generalized description of the spherical 

three-layer resonator with an anisotropic dielectric 

material,” IEEE AP Symp, June 1987, pp. 307-310 

Faceting f (GHz) 

8.8 

8.7 

8.6 

8.5 

8.4 

8.3 

8.2 

8.1 

45˚ 8.75 

30˚ 8.54 

15˚ 8.53 

10˚ 8.40 

7.5˚ 8.40 

5˚ 8.39 

22.5˚ 8.38 

45 30 15 10 7.5 5 

ΔF=0.1% Mesh Time 

10˚ rect. 53k 16:40 

22.5 curv. 6k 00:55 

Rectilinear 

Analytic 


New Element Technology 

Mixed Element Orders 


Mixed Element Orders 

49000 

42000 

35000 

28000 

21000 

14000 

7000 

0 

1 3 5 7 9 11 13 15 17 

1400 

1200 

1000 

800 

600 

400 

200 

0 

Mesh 1st 

Mesh Mixed 

Memory Mixed 

Memory 1st 

• Automatic localization of basis 

functions 

• Refinement via element size and 

order 

• Locally efficient use of computing 

resources 

First-Order, 16:23, 1.40GB 

Mixed-Order, 7:55, 0.985GB 


Log Periodic over EBG 

Groundplane 

• High geometric detail with large 

homogeneous radiation volume 

• Compare mixed order vs. 1 st 

order 

– 28% reduction in solution time 

– 29% reduction in memory 

• Mixed order converges faster 

– 12 passes vs. 14 passes 

– Average order = 0.96 

• S11 @ 12 GHz 

– 1 st S11 = 0.86584 

– Mixed S11 = 0.86511 


Introducing Adjoint Method 

Based Deriviatives 


Adjoint Derivatives 

• New Capability for sensitivity, tuning, and optimization 

• Compute the derivatives of SYZ parameters with respect to project and 

design variables 

• Eliminates need to solve multiple variations with small differences and 

numerical noise 

– More efficient and more accurate 

• Provides real-time tuning of reports to explore effects of small design changes 

• Improves derivative-based optimization methods 

2008 IEEE MTT-S Digest, pp. 527-530 


Sensitivity of |S11|, Combline Filter 

Ri 

G2 

G1 G2 

G1 – gap between center 

tuner and resonator 

G2 – gap between off-center 

tuners and resonators 

Ri 

Ri – inner radius of coax feed 

Note: for sensitivity with respect 

to Ri, ports are involved 

dS11_dp [1/m] 

10000 

5000 

0 

-5000 

-10000 

-15000 

9 

9.15 

9.3 

9.45 

9.6 


9.75 

9.9 

10.05 

10.2 

10.35 

freq [GHz] 

10.5 

10.65 

10.8 

10.95 

This filter design is: 

- Most sensitive to change in gap G2 

- Least sensitive to change in coax radius Ri 

0 

-10 

-20 

-30 

-40 

-50 

-60 

|S11| [dB] 

d|S11|_dRi 

d|S11|_dG1 

d|S11|_dG2 

|S11|

Local Derivatives Speed-up 

Optimization 

• Goal: Minimize reflection in 

waveguide quarter wave 

transformer 

• SNLP optimizer uses derivative 

information to speed-up 

calculation of response surface 

Example Optimization without Derivatives 

Example Optimization with Derivatives 


SMA launch 

• SMA launch is typical multi-variable design problem 

• Design variables: 

– length, radius of via stub, radius of antipads, radius 

of signal pads, radius & antipad of ground via 

• Solve for the derivatives of many variables at once 

Nominal Values for 

Design Variables 

Specify Desired Derivatives 

in Solution Setup 


Real-Time Tuning with Analytical 

Derivatives 

• Real-time tuning shows effects of 

small changes on S-parameters 

New Derivative 

Context in 

Report Editor 

S-parameters of Nominal Design 


S 11 

S 21 

Quickly Explore Effects of Small 

Changes on S-parameters

Improved GUI and Modeler 


Post-Processing Variables 

• New type of variable whose value 

can be modified without resimulating 

model 

• Optimize complex weights of 

antenna elements in phased array 

– Optimize for side-lobe location 

and main beam peak 

Optimization of Phased Array Excitations 

Synthesized Far-field Pattern 


Convergence Based on Multiple 

Output Variables 

• Evaluate and save multiple 

expressions vs. adaptive pass 

– Includes SYZ parameters, 

local, near and far field 

– Fully integrated with reporter 

and Optimetrics 


Clip Plane Viewing 

• Project preview 

– Image and notes 

available in File Open 

– Image available in 

Windows Explorer 

• Clip plane 

– Interactively slice 

through arbitrary plane 

– Can view model 

geometry, mesh plots, 

field plots, etc. 


Select by Area Mode 

• Enable material override 

– Conductors override 

dielectrics 

– Smaller objects override 

larger objects with same 

material 

– Avoids need for explicit 

subtractions 

• Select objects by area 

– Click and drag to rubber-band 

select 

– Right-to-left selects all objects 

passing through window 

– Left-to-right selects all objects 

inside window 


Overlay Far Field Plots on Model 

• Visualize radiation patterns on model geometry 

– Control transparency and/or size of pattern overlay 


Array Variables 

Assign array 

variable to 

Material property 

Supported at 

design level only 


New Modeling Commands 

• Fillets and 

Chamfers on 

2D objects 

• Sheet wrapping 

• Sheet and body 

imprinting with 

projection 

“Modeler/Chamfer (Fillet)” 


Streamline plots 

Streamline plot of Poynting vector 

on this face. Streamlines originate at 

discrete points on the face 


Integration with ANSYS 

DesignXplorer 


ANSYS DesignXplorer in R12.1 

and HFSS 12.0 

WR90 Transition 


height 

WR137

DX – Response Surface 


DX – Robust Design (DOE) 


Six Sigma 


Additional New Features 

1. 64 bit meshing 

2. 2D chamfers and fillets 

3. Like material override 

4. Sheet wrapping around solid 

5. Extended precision for ports – lower frequency solutions 

6. Improved remote simulation setup 

7. Post-processing variables/Optimetrics 

8. 3D overlay of far/near fields on model 

9. Port post-processing on fields 

10. Matched terminal s-parameters 

11. Modeler selection by area filter 

12. Fixed distance padding for region 

13. User Defined Keyboard shortcuts 

14. Expression cache 

15. Multiple output variable convergence 

16. Overlap/intersecting object selection from message window 

17. ACIS R19 SP2 upgrade 

18. Extended healing capability 

19. Improved setup for analytic ports 

20. Project specific script recording 

21. Define parametric sweep from file 

22. Improved far field data link. More efficient 

23. Project Preview – Both file open and in Windows Explorer 

24. Flexible history editing 

25. Polyline cross-section 

26. Move edge and detach edge 

27. Mode filtering for report setup 


HFSS 12.0: Available Now!

Introducing HFSS 12.0 - Ansys

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