Efficient Windscreen Antenna Modeling for EMC problems solved with FEKO

M. Schick¹, U. Jakobus², Marlize Schoeman²

¹EM Software & Systems GmbH, Germany; ²EM Software & Systems - S.A. (Pty) Ltd, South Africa

Numerical methods, such as MoM with different extensions, FEM, FDTD with variations like FIT and others, have problems with analyzing integrated windscreen antennas. A windscreen basically is a thin curved dielectric consisting of glass. Modeling this type of material with a full wave approach is very elaborate (very fine mesh) and consequently has a very high memory requirement. The effect of this dielectric is important as it shifts the resonance frequency of the antenna, so neglecting the glass during the simulations is not a viable option. In the last years efficient approximation methods have been developed which e.g. are converting the effect of the glass into an equivalent coating of wires. This works quite well in many cases but there are application examples (e.g. closely spaced wire elements) where this approximation is not accurate enough. Thus a new more accurate method has been developed and implemented in FEKO based on a heuristic modification of the MoM matrix elements. The advantage of this method is that no additional unknowns are required to consider the effect of the glass (i.e. same model complexity as compared to modeling the antenna in free space

Simulation of Emissions of Power Electronic System Components in Electrical and Hybrid Electrical Vehicles

Stephan Frei, Frank Kremer

Department of Electrical Engineering and Information Technology, Technische Universität Dortmund, Germany

The high voltage supply system in electrical (EV) and hybrid electrical (HEV) vehicles can lead to serious problems regarding electromagnetic compatibility. In this presentation the modeling and simulation of important components of an electrical drive system like shielded cables and connectors is described. Several simulation approaches like field and circuit simulation had to be combined with transmission line models to get required results. The inverter system was modeled and simulated using VHDL-AMS. The link from field simulation to circuit simulation was realized with a model order reduced coupling model derived from S-parameter computations. Each component model and the total system simulation approach were verified by measurements. Special emphasis was given to the very critical lower frequency range. The EMC behavior of a vehicle electrical drive system can be optimized based on this modeling approach.

Real World Cable Modeling for Automotive Applications

Paul Duxbury

CST UK Ltd, UK

Modern vehicles are full of electronics systems for control, navigation, entertainment and communication, and can contain several kilometers of wiring. Ensuring electromagnetic compatibility within such a complex environment is a significant challenge. EM modeling can play an important role in optimizing the system layout to reduce interference, radiated emissions and improve the immunity to external sources. However, this is an extremely challenging problem due to the large differences in scale. A car may be approaching 5m in length compared with the cables which may have cross sections of only 1mm or so - representing up to 4 orders of magnitude difference in scale! The cable harness may be very complex including shielded or unshielded twisted pairs, coaxial cables and ribbon cables. The cable will typically follow a curved path through the structure and there may be multiple splits and junctions. By using a combination of 3D full wave EM modeling and 2D transmission-line analysis, such problems can be efficiently tackled within CST STUDIO SUITE_, crucially avoiding the need to mesh the detail of the cable cross section in the 3D field solver.

Recent Achievements in Computational Techniques Related to Automotive EMC simulations

Roman Jobava¹, Faik Bogdanov¹, Anna Gheonjian¹, Ekaterina Yavolovskaya¹, David Karkashadze¹, Paata Tsereteli¹, Christoph Ullrich², Detlef Schleicher³, Hicham Tazi²

¹EM Consulting and Software, EMCoS Ltd., Tbilisi, Giorgia; ²AUDI AG, Ingolstadt, Germany; ³VW AG, Wolfsburg, Germany

In this presentation recent achievements in computational techniques, related to automotive EMC simulations are discussed. Computer simulations with numerical analysis can significantly reduce time and resources spent for development. However, accurate modeling of such complicated systems, as automobile with all its electronics, cables and antennas, requires the combined usage of traditional and special methods and techniques with the facility for fast numerical solutions. In the presentation we describe a set of new methods and techniques based on enhancement of the traditional Method of Moments (MoM) and Multi-Transmission Line (MTL) theory:

• Hybrid MoM scheme with special Green Function for investigation of interaction between cables and glass antenna structures
• MoM and Multiport Network model hybridization
• MoM Matrix Partitioning solution for optimization problems
• Efficient solution of MTL Equations
• Shielded cable models
• Low frequency solutions

Application of these methods and techniques provides an accurate and effective solution of electromagnetic problems related to automotive EMC. After a description of each method or technique industrial application examples are presented.

Comparisons between Time-Domain and Frequency-Domain simulations applied to an entire vehicle

Marco Klingler, Salah Benhassine, Yannick Merle

PSA Peugeot Citroen, Vélizy-Villacoublay, France

Frequency-domain and time-domain numerical EM codes have both their advantages and their drawbacks. This is not only from a computational point of view, but also from an application point of view which is related to the development process of a product such as a vehicle. This presentation will focus on the use of two commercial simulation tools, FEKO and Microwave Studio, to compute the electromagnetic field at different locations inside an entire vehicle during immunity tests with off-vehicle radiation sources following ISO 11451-2 standard. The modeling constraints and the characteristics of the vehicle will be given, and for each simulation tool, a description of the specific radiation sources will be detailed. The adjustments of the vehicle model and the chosen simulation parameters, specific to each tool, will be defined. Results obtained using these two simulation techniques will be analyzed and discussed, and the differences between results will be compared to those that can be obtained experimentally between different test laboratories.

Simulations for Improved Performance of Tire Pressure Monitoring Systems

Todd Hubing, Hua Zeng

Clemson University International Center for Automotive Research, United States

The performance and reliability of tire pressure monitoring systems that employ battery-powered wireless transmitters is highly dependent on the efficiency of those transmitters. Optimizing the performance of these systems requires a trade-off between antenna size, bandwidth, cost and efficiency. Current products made by different manufacturers employ a wide variety of electrically small antenna designs; and accurate simulation is an important part of the design process. This presentation demonstrates how simulations are used (and often misused) to design antennas for TPMS systems.

Automotive EMC and Computer Aid Design of PCBs - Signal Integrity, Power Integrity, Ground Integrity

Jean-Roger K. Kuvedu-Libla

Delphi Electronics & Safety, Bascharage, Luxemburg

The investigations of Electromagnetic Compatibility (EMC) remain in the automobile industry cost and time intensive aspects when designing vehicle onboard equipment. The demands of Automotive EMC Directives 72 / 245 / EEC (95 / 54 / EC) or EMC-Directive 2004/108/EC have also increased in the last decade the pressure on the vehicle manufacturers and their onboard equipment suppliers. The question is how to solve in a short product development time the design challenges of "Printed Circuits Board" (PCBs) with a high reliability and significant cost reduction. This demands to speed the design work process particularly in the earlier product development phase. For that many challenges were addressed to the Automotive EMC experts to work on new technologies different and but complementary to the common immunity and emission measurement techniques. Today important challenges are how the application of the "Signal-, Power- and Ground-Integrity" can be benefited for the intention in the automobile industry when using Computer Aid design tools? The purpose of the present workshop contribution is to show today Computer Aid Design techniques used to evaluate the design weakness of the onboard electronics and predict the risks of the electromagnetic compatibility measurements during the product development phase. This workshop contribution is to prove whether the "Signal-, Power- and Ground-Integrity" are appropriate as new Computer Aid Design techniques for the electromagnetic investigations on PCBs. The principal goals of the Computer Aid Design technique usage shall be to prove an optimal PCB design review when applying the so-called "Design Rule Check" (DRCs). In addition it shall be to foresee particularly the risks of the electromagnetic emission when designing the PCBs and simulating the critical signals on the PCBs. Finally, explanations of the relationship between the Automotive EMC and the "Signal-, Power- and Ground-Integrity" and definitions of "EMC Simulation" will conclude the workshop.

Components characterization and their influence on filters behavior for automotive applications

Flavio Canavero¹, Cyrous Rostamzadeh²

¹Politecnico di Torino, Italy; ²Robert Bosch LLC, Automotive Group, Farmington Hills, United States

Automotive EMI filters are often used on power networks to reduce high-frequency noise from being conducted off the printed circuit boards and resulting into EMI problems. The filter performance is difficult to predict and often compromised at high frequencies due to parasitics associated with the filter itself, or the PCB layout. A methodology is presented to build lumped-element SPICE models of filter components based on their frequency-domain characterization. The synthesized models take into account of physical non-idealities of filter components (e.g, the frequency-dependent behavior of ferrite elements) and can include parameters variability to account for manufacturing dispersion. The presentation outlines how the use of such models and the PCB implementation of the filter effectively help to optimize the filter performance and limit EMI problems in practical applications.

Introduction

Mauro Feliziani

University of L'Aquila, Italy

Human Body Modeling

Valerio De Santis

University of L'Aquila, Italy

Electromagnetic Modeling

Francesca Maradei

Department of Electrical Engineering, Sapienza University of Rome, Italy

Thermal Modeling

Mauro Feliziani

University of L'Aquila, Italy

An Electromagnetic Model to Investigate the Heart Stimulation by Magnetic Field Pulses

Graziano Cerri, A. De Leo, R. De Leo, G. Della Chiara, V. Mariani Primiani, F. Moglie, A. P. Pastore, P. Russo

Universita' Politecnica delle Marche, Ancona, Italy

Microwave Imaging for Breast Cancer Detection

Valerio De Santis¹, Elise C. Fear²

¹University of L'Aquila, Italy; ²University of Calgary, Canada

Introduction to EMC in Railways: Definitions of EMI and EMC; sources of interference within the Railway environment eg Traction inverter drives; coupling mechanisms

Chris Marshman

York EMC Services Ltd, United Kingdom

Application of the EMC Directive to Railways; discussion on Fixed Installations

Chris Marshman

York EMC Services Ltd, United Kingdom

Railway EMC standards: EN 50121-x: 2006

Chris Marshman

York EMC Services Ltd, United Kingdom

The need for other 'local' standards eg London Underground and Network Rail Standards

Chris Marshman

York EMC Services Ltd, United Kingdom

EMC Management: Management/Control Plans; test plans; EMC compliance evidence: test reports, gap analyses

Ade Ogunsola Parsons

EMC Measurements - including a novel technique for the measurement of emissions from moving trains, in particular high speed trains

Chris Marshman

York EMC Services Ltd, United Kingdom

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