Antenna Simulation Overview

Transcription

1 Antenna Simulation Overview Marc Rütschlin, Senior Application Engineer 2011 CST European UGM May

2 Antenna Choice Analysis Optimisation Environment Antenna Design Flow 2011 CST European UGM May

3 Choosing an antenna... Antenna Magus Explore database Design antenna Synthesise array Estimate performance Export! 2011 CST European UGM May

4 Categories of Antennas 2011 CST European UGM May

5 Solver Selection Technique Transient FIT-T, TLM Finite Element FEM Integral MOM, MLFMM Approach Time domain (Broadband) Single frequency Single frequency Volume hex PBA, Subgridding Volume hex, tet Curved Tetrahedrons Surface Meshing Robust Cheap Conformal Complex Expensive Conformal Complex Dielectrics? Numerical Effort O(n) O(n 2...n 3 ) O(n log(n)...n 3 ) Time step? Push button No numerical dispersion error 2011 CST European UGM May

6 Selected Examples 2011 CST European UGM May

7 Ultra Wideband Antennas Direct pulse communication Typical frequency range: 3.1 to 10.6 GHz Tailored signal Natural solver choice: Excited pulse broadband, transient farfield Received pulses 2011 CST European UGM May

8 Ultra Wideband Antennas Design goals for UWB Antenna Automatic postprocessing optimization goals. return loss < -10 db group delay = flat a cross-correlation peak Correlation Peak 2011 CST European UGM May

9 Mobile Phone Simulation Advanced Interface Imported Structures Bending Robust Meshing (PBA) Efficient Solvers 2011 CST European UGM May

10 Mobile Phone Simulation Full Phone Evaluation Post-processing! Total radiated power / TIS System simulation Matching Circuit / Load Pull MIMO / Diversity Envelope Correlation Hearing Aid Compatibility (HAC) 2011 CST European UGM May

11 Mobile Phone Simulation Biological Impact: of body on phone... TRP including body model of phone on body... Specific Absorption Rate (SAR) < 2 W/kg 2011 CST European UGM May

12 RFID Low Frequency Near (H-)field coupling Electrically small MHz reader coil tag 2011 CST European UGM May

13 RFID Low Frequency Near (H-)field coupling Electrically small λ = 22.2 m MHz reader coil tag small size & features small time step! 2011 CST European UGM May mm gap = 10-5 λ!

14 RFID High Frequency Radiating antenna RFID chip NXP G2XM chip Poor Z = 14.8 match? j128 Ω 915 MHz S 11 = -8 db S 11 = -0.3 db 0.15 mm courtesy of UPM RFID CST European UGM May

15 RFID High Frequency Radiating antenna RFID chip or, depending on antenna 915 MHz 0.15 mm courtesy of UPM RFID CST European UGM May effect of chip on fields

16 RFID High Frequency Radiating antenna RFID chip Tag in situ peaks dips hours... 4 GB RAM hours GB RAM 2011 CST European UGM May

17 RFID High Frequency Radiating antenna RFID chip Reader System 2011 CST European UGM May

18 Reflector Antennas Electrically large Lots of air! 12 GHz λ = 25 mm Options: 1. full wave simulation 2. split the Don t mesh the volume! problem Large volume to surface ratio? 400 mm 16 λ 2011 CST European UGM May

19 Reflector Antennas Options: 1. full wave simulation 2. split the problem 100 % 10 % Assembly Mode in CST DS % 5 % 1 % reflector farfield as a function of feed geometry Use the appropriate solver(s)! Optimise the system CST European UGM May

20 radome Installed Performance Electrically large Full wave simulation stacked bicone omnidirectional antenna 3.5 GHz feed 2011 CST European UGM May

21 Installed Performance Electrically large Full wave sim CST European UGM May

22 Installed Performance Electrically large Farfield source Options: 1. full wave simulation 2. split the problem 3 hours 3 min 4 min 2011 CST European UGM May

23 Installed Performance Electrically large Field sources Co-site analysis radome 2011 CST European UGM May

24 Small Antenna Arrays All elements different simulate all! Optimise post-processing combination of fields CST European UGM May

25 Small Antenna Arrays All elements different simulate all! Optimise post-processing combination of fields. Original beam shape Optimised beam shape amplitude weightings 2011 CST European UGM May

26 Large Antenna Arrays Most elements the same simulate one. HPC full simulation to account for edge effects. array factor unit cell boundary condition scan blindness at 45 strong radiation at CST European UGM May

27 Matching Networks Coil operating at MHz CST DESIGN STUDIO 2011 CST European UGM May

28 Conclusion Complete Technology... Methods to suit any task! Automated processing of results... Get the output you want! 2011 CST European UGM May