Multiscale Simulation for Automotive Radar

Transcription

1 Multiscale Simulation for Automotive Radar Marc Rütschlin Acknowledgments: Franz Hirtenfelder, Hassan Chreim

2 Automotive Radar Architecture Our Topic Radar Architecture: Emitters and receivers (antennas) RF Module (LNA, HPA, filters, modulators ) DSP (Processors, RAM ) 2

3 Choose Solver to Match Problem Type 3

4 Automotive Radar Range of Scale Range of scales at 77 GHz: 5λ >1000λ Antenna Antenna + Radome Module Integrated inside Platform 4

5 Automotive Radar Range of Scale Range of scales at 77 GHz: 5λ >1000λ Antenna Antenna + Radome Module Integrated inside Platform 5

6 Simulation Approach for Antenna Relatively small structure full-wave solver with volumetric mesh Time Domain solver Larger structures Planar antennas Non-resonant antennas Smallest detail: 0.025λ Largest extent: 5λ Frequency Domain solver Curved structures Very fine details Many ports High Q antennas 6

7 Antenna Magus for Antenna Design Different options for radar antennas, but how to design them? Provides antenna designs with CST models that are: Fully parameterized Ready for modification and more complex optimization Ready for integration in module 7

8 Radar Antenna Design (from Literature) E-theta E-phi Matching Elevation Azimuth 8

9 Radar Dual Antenna Design E-theta_Tx E-phi_Tx E-theta_Rx E-phi_Rx Tx Rx S-Matrix Elevation Elevation 9

10 Antenna Performance Indicator: Phase Difference Observation point Phase difference between Rx and Tx farfields Tx Rx Smooth falling phase difference indicates useful angular range of the radar 10

11 Automotive Radar Range of Scale Range of scales at 77 GHz: 5λ >1000λ Antenna Antenna + Radome Module Integrated inside Platform 11

12 Simulation Approach: Antenna with Radome Larger structure with dielectrics full-wave time domain approach Time Domain solver Possibly complex thick layered dielectrics volumetric mesh required Smallest detail: 0.025λ Largest extent: 14λ Relatively large T-solver numerically more efficient than F-solver Imported CAD no meshing problems 12

13 Effect of Radome on Antenna Performance Antenna only Gain_E-theta Gain_E-phi Phase_E-phi Phase_E-Phi With radome 13

14 Effect of Radome on Antenna Phase Performance Antenna only Phase difference between Rx and Tx farfields With radome 14

15 Effect of Radome on Antenna Phase Performance Antenna only Phase difference between Rx and Tx farfields With radome

16 Automotive Radar Range of Scale Range of scales at 77 GHz: 5λ >1000λ Antenna Antenna + Radome Module Integrated inside Platform 16

17 Simulation Approach: Antenna in Vehicle Structure too large for volumetric mesh solver hybrid technique required Largest extent: 1180λ Finely detailed antenna full wave solver with volumetric mesh Huge complex imported CAD surface mesh based solver that can handle poorly CAD quality Smallest detail: 0.025λ Combined multiscale approach required! 17

18 Simulation Approach: Antenna in Vehicle Hybrid approach combining full-wave and ray tracing approach required 18

19 Antenna Interaction with Vehicle Interior Observe the initial hit points The antenna does not only radiate in the intended direction. 19

20 Antenna Interaction with Vehicle Interior 0-80 Observing the ray paths can help us understand the origins of spurious radiated fields and devise ways of mitigating them. 20

21 Antenna Interaction with Vehicle Interior Ray paths inside vehicle Histogram of reflected path lengths Understanding ray behavior inside vehicle can help identify sources of ghost images. 21

22 Antenna Radiation Beyond the Vehicle E-Field magnitude (based on 1 W applied power) 24

23 Radar Calibration: Single Target Detection Triple reflector Incidence 1 st order reflection 3 rd order reflection 25

24 Radar Calibration: Single Target Detection Tx Rx The radiation patterns of both Tx and Rx antennas are clearly affected by the reflector. 26

25 Radar Calibration: Single Target Detection The phase difference shows a jump at the corresponding position of the target. 27

26 Radar Calibration: Multiple Target Detection 0-30 Top View 28

27 Radar Calibration: Multiple Target Detection Tx Rx Directivity shows shadowing effect of both targets. 29

28 Radar Calibration: Multiple Target Detection The phase difference shows a jump at the corresponding positions of the target. 30

29 Radar Performance: Realistic Target Detection 31

30 Radar Performance: Realistic Target Detection Observation angles:

31 Radar Performance: Realistic Target Detection Reflection appearance from multiple directions of incidence? The sinogram provides a fingerprint of target vehicles. 34

32 Radar Performance: Realistic Target Detection The hotspot analysis tells us which areas reflect most strongly. Can we design vehicles to be better reflectors for radar observation? 35

33 Complete Technology for Automotive Radar Design Antenna Antenna + Radome Module Integrated inside Platform 36

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