using feko for electromagnetic simulations in the...

Copyright © 2008 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.

Using FEKO for Electromagnetic

Simulations in the Automotive Environment

Dr. Ulrich Jakobus

EM Software & Systems

www.emss.de / www.feko.info


Contents

Introduction

• Electromagnetic environment

Computational methods

• Overview

Application Examples

Summary and Conclusion


Introduction

Antenna analysis in complex environments.


3D EM Simulation Map

Complexity of Materials

Electrical Size


3D EM Simulation Map

Complexity of Materials

UTD

PO/GO

MOM

FEM

MLFMM

Electrical Size


Analysis of vehicle-mounted antennas

Fender antenna for VW Beetle

Creation of a computational model

Details that can be included:• Transition resistances at hinges and

door locks

• Lossy dielectric ground (wet, dry)

• Plastic parts (e.g. bumper, seat)

• Glass windscreen

CAD model

Mesh



Surface current distribution

Horizontalfar-fieldpattern

• Fender antenna for VW Beetle• Transmitting case (same patter as

receiving due to reciprocity)



MeasurementComputation

• Rod antenna at 100 MHz



GPS Antenna

Radiation Pattern


Effect of Conducting Windows

Conductive layer for thermal protection

Effect modelled using thin dielectric sheet

formulation

Far Field Gain vs Angle

Phi [Deg] at Theta = 90.00 [Deg]

With windows No Windows

0º 345º330º

315º

300º

285º

270º

255º

240º

225º

210º195º180º165º

150º

135º

120º

105º

90º

75º

60º

45º

30º15º 0º

0

-2

-4

-6

-8


ICNIRP Compliance for TETRA Radio System

Low current density

High current density

Maximum localised SAR

High E-field values

Low E-field values


Tire Pressure Sensor Radiation Analysis

Front tire antenna excitation Rear tire antenna excitation

Opposite side -53.8 dBV/m

True side -49.7 dBV/m

Opposite side -61 dBV/m

True side -55 dBV/m

Y. Yamada, K. Tanoshita, K. Nakatani, S. Horiuchi, “FEKO Simulations and Measurements of Electrical Field Distributions around a Car,” ACES 2007, Verona, Italy, March 2007


Optical Controller

Spectrum Analyser

Field Distributions Inside a Vehicle - Verification

Measured

Simulated

Y. Yamada, K. Tanoshita, K. Nakatani, S. Horiuchi, “FEKO Simulations and Measurements of Electrical Field Distributions around a Car,” ACES 2007, Verona, Italy, March 2007


EMC Coupling Problem (Exhaust Pipe)

Coupling between engine area and

the receiving antenna at the rear of

vehicle (resonance on exhaust at 24 MHz).

f = 24 MHz

f = 27 MHz


Aircraft Antenna Placement: Validation

M. V. T. Heckler* and A. Dreher,

Analysis of Monopoles Installed on

Airframes, 2005 IEEE APS

Symposium, Washington DC, July 2005

VHF Com Antennas – 126MHz



Air Traffic Control Antenna at 1GHz λ/5 Mesh with 193,212 trianglesMoM/PO Hybrid Technique

Measurements – 1/12th scale model



Air Traffic Control Antenna at 1GHz


Summary and Conclusion

Introduction• Antenna Design

• Electromagnetic Environment

Computational methods• Overview

Application Examples• Different Antennas

• Tyre Pressure System

• EMC Applications

using feko for electromagnetic simulations in the...

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