Electromagnetic Compatibility (EMC)

EMC of Complex Systems

Ph. D. Thesis Fabian Happ. 01.04.2012 – 01.09.2017

In this thesis a numerical method based on the Method of Moments and analytical formulations are developed to calculate electromagnetic fields in the vicinity of Carbon Fiber Composite (CFC) materials. The methods are applied to predict the shielding effectiveness of different CFC materials, to calculate lightning transfer functions for the coupling into an aircraft geometry made of CFC, and to estimate the influence of CFC on the crosstalk between transmission lines.

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Current distribution on a field illuminated Computer casing
(Source: TET, TUHH).

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Apertures in a Computer casing
(Source: TET, TUHH).

Related Publications:

Fabian Happ, Arne Schröder, Gazmend Mavraj, Heinz-Dierich Brüns, Frank Gronwald
Numerical Shielding Analysis of Anisotropic Multilayer Materials by the Method of Moments
IEEE Transactions on Electromagnetic Compatibility, Vol. 59, No. 1, February, 2017

Fabian Happ, Heinz-Dietrich Brüns, Gazmend Mavraj, Frank Gronwald
Numerical Computation of Lightning Transfer Functions for Layered, Anisotropically Conducting Shielding Structures by the Method of Moments
Advances in Radio Science, Special Issue: Kleinheubacher Berichte 2016

Fabian Happ, Gazmend Mavraj, Heinz-Dietrich Brüns, Frank Gronwald
On the Choice of Huygens’ Surfaces in the Vicinity of Electrically Small Apertures
EMC Europe, Wroclaw, Poland, September 5 – 9, 2016

Fabian Happ, Frank Gronwald, Heinz-D. Brüns
An Extension of Schelkunoff’s Shielding Theory to Anisotropic Conducting Multilayer Materials
Joint IEEE International Symposium on Electromagnetic Compatibility and EMC Europe, Dresden, Germany,
August 16-22, 2015

Fabian Happ, Heinz-D. Brüns, Frank Gronwald
Benchmark Calculations of Magnetic Shielding at Low Frequencies
IEEE International Symposium on Electromagnetic Compatibility, EMC Europe 2014, Göteborg, Schweden, September 1-4, 2014

Fabian Happ, Heinz-D. Brüns, Frank Gronwald
Numerische Simulation der Schirmwirkung von mehrlagigen, anisotrop leitfähigen Materialien
Internationale Fachmesse und Kongress für Elektromagnetische Verträglichkeit (EMV Düsseldorf) , Düsseldorf, Germany, March 11-13, 2014

Frank Gronwald, Fabian Happ
Methoden der Netzwerkmodellierung von Transferfunktionen indirekter Blitzeffekte auf Grundlage numerischer Simulation in Zeit- und Frequenzbereich
Internationale Fachmesse und Kongress für Elektromagnetische Verträglichkeit (EMV Düsseldorf) , Düsseldorf, Germany, March 11-13, 2014

Frank Gronwald, Fabian Happ
Adaptive Macromodelling of Lightning Transfer Funcion from Numerical Calculations in Time and Frequency Domain
International Conference on Electromagnetics in Advanced Applications,Torino, Italy, September 9-13, 2013

Fabian Happ, Arne Schröder, Heinz-Dietrich Brüns, Frank Gronwald
A Method for the Calculation of Electromagnetic Fields in the Presence of Thin Anisotropic Conductive Layers using the Method of Moments
EMC Europe 2013, Brugge, Belgium, September 2-6, 2013

HIRF Protection Using Energy Selective Diode Arrays

Cheng Yang, M. Sc., (China Scholarship Council (CSC)), 01.04.2015 – 17.10.2016

With more and more electromagnetic energy being transmitted by radar, radio, TV, mobile, hotspot (Wi-Fi), satellite, and other transmitters, detrimental effects of electromagnetic waves on the environment, e.g. disturbance or even damage of electronic equipment, become more and more a concern. To ensure safe operation of various electronic systems in transmitting or receiving states, electromagnetic protection should be considered especially against high intensity radiation fields (HIRFs). This project focuses on diode arrays for implementation of self-activated and energy selective blocking of electromagnetic wave.

Based on the nonlinear behavior of diodes, diode arrays can be shown to be transparent with respect to small field amplitudes and opaque to large field amplitudes. In theory, we expect the structure to work like a spatial switch, while in practice its protection performance is limited by several factors, such as the response time and operating frequency range of the diodes, the transmission loss of the protective structure and near field coupling effects. Therefore, accurate full wave simulation are being used for evaluation of the electromagnetic performance of protective diode arrays. Up to now, mostly infinitely periodic diode arrays have been studied. Next steps include the simulation of finite and non-periodic diode arrays using the electromagnetic field simulator CONCEPT-II

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Geometrical model of diode array designed for vertical polarized protection against HIRF. The diode array consists of conductive strips and miniature diodes on a low dielectric loss substrate of thickness 0.8mm. The horizontal and vertical distance of adjacent diodes is 3.5 mm and 2.25, respectively (figure adapted from “A Novel Method of Energy Selective Surface for Adaptive HPM/EMP Protection,” IEEE APWL, vol. 12, pp. 112–115, 2013.)

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Evaluation model of diode array in CONCEPT-II. The array was placed in the front window of a PEC box, and a receiving antenna is positioned inside the PEC box (side length approx. 50 cm). What can be seen are the surface currents on the PEC box (red color indicates high current amplitudes).

Related Publications:

Cheng Yang, Heinz-D. Brüns, Peiguo Liu, Christan Schuster
Impulse Response Optimization of Band-Limited Frequency Data for Hybrid Field-Circuit Simulation of Large-Scale Energy-Selective Diode Grids
IEEE Transaction on Electromagnetic Compatibility, Vol. 58, No. 4, August 2016

Cheng Yang, Heinz-D. Brüns, Peiguo Liu, Christian Schuster
Validation of a Flexible Causality Treatment for Transient Analysis of Nonlinearly Loaded Structures
Joint IEEE International Symposium on Electromagnetic Compatibility and EMC Europe, Dresden, Germany,
August 16-22, 2015

Analysis of Electromagnetic Interference in Server Casings

Ph.D. Thesis Alexander Vogt. 01.04.2011 – 08.04.2016

With increasing data rates EM emission has become a major issue for EMC and EMI considerations in current server designs. Major sources of EM emission inside include ICs, cables and connectors, and Printed Circuit Boards. While efficient techniques exist to model the interior coupling of PCB cavities (Zpp ), the external (3D) coupling still has to be computed using full-wave techniques.

This project aims to combine the different methods to model and simulate the components of the server. The dimensions and high data rates in addition to the high complexity of the individual components encountered in modern servers lead to a number of unknowns that are commonly in the range of several million. Therefore, efficient numerical methods and approximate models have to be developed.


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Sources of EM emission and related structures inside a server housing. (Source: TET, TUHH).


Picture1

Modeling the 3D coupling of PCBs using PEC surfaces and dielectric bodies for computation with the Method of Moments (Concept-II). (Source: TET, TUHH).

Related Publications:

Alexander Vogt, Torsten Reuschel, Heinz-D. Brüns, Sabine Le Borne, Christian Schuster
On the Treatment of Arbitrary Boundary Conditions Using a Fast Direct H-Matrix Solver in MoM
IEEE Transactions on Antennas and Propagation, Vol. 64, no.8, August 2016

Alexander Vogt, Heinz-D. Brüns, Christian Schuster
Auswirkung absorbierender Materialien auf die Verkopplung von Komponenten innerhalb eines PC-Gehäuses
Internationale Fachmesse und Kongress für Elektromagnetische Verträglichkeit (EMV Düsseldorf) , Düsseldorf, Germany, February 23-25, 2016

Alexander Vogt, Heinz-D. Brüns, Qi Wu, Frank Gronwald, Christian Schuster
A Measurement Setup for Quantification of Electromagnetic Interference in Metallic Casings
IEEE Transactions on Electromagnetic Compatibility, vol.57, no.6, Dezember 2015

Alexander Vogt
Workshop: Solving highly resonant structures using a fast direct H-matrix solver in the method of moments
IEEE EMC International Symposium on Electromagnetic Compatibility, Dresden, Germany, August 2015

Alexander Vogt, Heinz-D. Brüns
Workshop: Modeling using MoM – Solving challenging realworld problems
IEEE EMC International Symposium on Electromagnetic Compatibility, Gothenburg, Sweden, September 2014

Alexander Vogt, Heinz-D. Brüns, Christian Schuster
Einfluss von absorbierenden Materialien auf die elektromagnetische Strahlung von Leiterplatten
Internationale Fachmesse und Kongress für Elektromagnetische Verträglichkeit (EMV Düsseldorf) , Düsseldorf, Germany, March 11-13, 2014

Alexander Vogt, Heinz-Dietrich Brüns, Helge Fielitz, Christian Schuster
Modeling Absorbing Materials in Cavities with Apertures Using the Thin Sheet Approximation
Asia-Pacific EMC Symposium (APEMC), Melbourne, Australia, May 20-23, 2013

Alexander Vogt, Heinz Brüns, Samuel Connor, Bruce Archambeault, Christian Schuster
Applicability of the Thin Sheet Approximation to the Analysis of EM Emission from Coated PCBs
IEEE EMC International Symposium on Electromagnetic Compatibility, Pittsburgh, USA, August 05-10, 2012

Application of the Characteristic Mode Analysis to Antenna Design and Electromagnetic Compatibility


Alexander-von-Humboldt Fellowship Prof. Qi Wu. 01.03.2014 – 29.02.2016

The Characteristic Mode Analysis (CMA) – based on the fundamental works of Harrington and Mautz – is a well-known numerical tool for antenna analysis and design. Within the numerical framework of the method of moments (MoM) the characteristic modes are found by the solution of a weighted matrix eigenvalue equation formulated with the MoM system matrix. The resulting current distributions are the eigencurrents and eigenvalues, respectively. The eigenvalues indicate if the corresponding eigencurrents may store primarily magnetic energy, or electric energy, or if they are “at resonance” and may radiate efficiently if excited. The eigencurrents constitute a set of (orthogonal) modes characteristic to the investigated structure (hence the name) and independent of any excitation. In antenna design inspection of the eigencurrents allows to identify e.g. suitable locations for generators and ways to improve radiation efficiency. In EMC analysis, the goals are opposite: analyze a potentially radiating structure and reduce its potential for emission.

During the Alexander von Humboldt Fellowship of Prof. Qi Wu at TUHH CMA was applied successfully to antenna design and extended to EMC analysis of digital systems. A full report of his fellowship is given in the following document PDF.


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General procedure to perform the CMA of metallic radiators: the analysis is split into four steps. Image taken from: “Characteristic Mode Analysis of Radiating Structures in Digital Systems,” IEEE Electromagnetic Compatibility Magazine.


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Eigencurrents in A/m and radiation eigenpatterns of a cubic heatsink on a motherboard at 500 MHz obtained by CONCEPT-II. Image taken from: “Characteristic Mode Analysis of Radiating Structures in Digital Systems,” IEEE Electromagnetic Compatibility Magazine.

Related Publications:

Qi Wu, Wei Su, Zhi Li, Donglin Su
Reduction of Out-of-Band Antenna Coupling using Characteristic Mode Analysis
IEEE Transactions on Antennas and Propagation, accepted for publication

Qi Wu, Alexander Vogt, Heinz-D. Brüns, and Christian Schuster
Characteristic Mode Analysis of Radiating Structures in Digital Systems
IEEE Electromagnetic Compatibility Magazine, accepted for publication

Qi Wu, Heinz.-D. Brüns, C. Schuster
Evaluation of Isolation between Blade Antennas in Pre-design Phase using a Synthesized Model
Asia-Pacific International Symposium on Electromagnetic Compatibility, APEMC 2016

Alexander Vogt, Heinz-D Bruns, Qi Wu, Frank Gronwald, Christian Schuster
A Measurement Setup for Quantification of Electromagnetic Interference in Metallic Casings
IEEE Transactions on Electromagnetic Compatibility, vol. 57, no. 6, pp. 1354-1364, Dec. 2015

Qi Wu, Xiaojing Ding, Donglin Su
A Compact Dipole Antenna with Curved Reflector for 1.0-4.2 GHz EMC Measurement
IEEE Transactions on Electromagnetic Compatibility, vol. 57, no. 6, pp. 1289 – 1297, Dec. 2015

Qi Wu, Alexander Vogt, Jan B. Preibisch, Andreas Hardock, Heinz.-D. Brüns, C. Schuster
Modeling of Mutual Coupling between Coaxial Probes in Flat Metallic Casings Using the Contour Integral Method
ICEAA-IEEE APWC 2015, International Conference on Electromagnetics in Advanced Applications, Torino, Italy, September 07-11, 2015

Qi Wu, Alexander Vogt, Heinz-D. Brüns, Frank Gronwald, Christian Schuster
Numerical and Experimental Evaluation of Electromagnetic Coupling between Radiating Antenna Structures inside a Computer Casing
Joint IEEE International Symposium on Electromagnetic Compatibility and EMC Europe, Dresden, Germany, August 16-22, 2015

Qi Wu, W. Su
Rigorous Eigenmode Analysis of Conducting Sphere
9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, April 12-17, 2015

Qi Wu, Siyuan Guo, Donglin Su
On the eigenmodes of small conducting objects
IEEE Antennas Wireless Propagation Letters, vol. 13, pp. 1667-1670, 2014

Qi Wu, Xiaojing Ding, Aixin Chen
A broadband dipole antenna for multiservice indoor distributed antenna system (MS-IDAS)
IEEE Antennas Wireless Propagation Letters, vol. 14, pp. 839-842, 2015

Qi Wu, Xiaojing Ding, Donglin Su
Theoretic and Experimental Analysis of a Reflector-backed Dipole Antenna for 1-3 GHz EMC Test
IEEE International Symposium on Electromagnetic Compatibility, EMC Europe 2014, Gothenburg, Sweden, September 1-4, 2014

Accurate and Efficient Algorithms in the Method of Moments for the Analysis of High Intensity Radiated Field
Coupling into Aircraft

Ph. D. Thesis Arne Schröder. 01.09.2009 – 31.08.2013

The evolution of electronic systems in aircraft emphasizes the importance for numerical simulations regarding electromagnetic field coupling into avionic systems. This thesis addresses accurate and efficient algorithms for a mehtod of moments based analysis of aircraft. The simulation efficiency for various problems is increased by exploiting redundancies in the initial numerical formulation. A coupled integral equation is introduced, enhancing the accuracy of the method of moments with regard to field coupling into aircraft. Various application examples, ranging from generic objects to real world aircraft, are used to proof the validity of these techniques and putting the attention on challenges arising from practical applications.

Picture PCB Interconnect

Bistatic radar cross section (RCS) of aircraft to the left. The comparison of two diffrent computation methods shows good agreement. (Source: TET, TUHH).


Picture Via Modell

Surface current density on an aircraft under plane wave illumination (aircraft model courtesy of HIRF SE partner Evektor, Czech Republic). (Source: TET, TUHH).

Related Publications:

Arne Schröder, Guido A. Rasek, Heinz-D. Brüns, Zdenek Reznicek, Jaromir Kucera, Steffen E. Loos, Christian Schuster
Analysis of High Intensity Radiated Field Coupling into Aircraft using the Method of Moments
IEEE Transactions on Electromagnetic Compatibility, vol. 56, no. 1, Februar 2014

Arne Schröder, Heinz-Dietrich Brüns, Christian Schuster
A Hybrid Approach for Rapid Computation of Two-Dimensional Monostatic Radar Cross Section Problems With the Multilevel Fast Multipole Algorithm
IEEE Transactions on Antennas and Propagation, vol. 60, no. 12, December 2012

Arne Schröder, Heinz-Dietrich Brüns, Christian Schuster
Fast evaluation of electromagnetic fields using a parallelized adaptive cross approximation
IEEE Transactions on Antennas and Propagation, vol. 60, no. 12, December 2012

Arne Schröder, Heinz-Dietrich Brüns, Christian Schuster
Efficient Compression of Far Field Matrices in Multipole Algorithms based on Spherical Harmonics and Radiating Modes
Advanced Electromagnetics, vol. 1, no. 2, 2012 and Advanced Electromagnetics Symposium (AES), Paris, France, April 16-19, 2012

Arne Schröder, Heinz-Dietrich Brüns, Christian Schuster
Beschleunigung schneller Löser in der Momentenmethode bei Einkopplungsproblemen mit Mehrfachanregung
Internationale Fachmesse und Kongress für Elektromagnetische Verträglichkeit, Düsseldorf; Germany, February 7-9, 2012

Arne Schröder, Guido A. Rasek, Steffen E. Loos, Heinz-Dietrich Brüns, Christian Schuster
Numerical and Experimental Investigations on a Metallic Fuselage Model with Apertures
EMC Europe Conference, York, United Kingdom, September 26-30, 2011

Arne Schröder, Heinz-Dietrich Brüns, Geoff South, Christian Schuster
Investigation of Field Coupling into a Carbon Fiber Aircraft Model with the Method of Moments
International Conference on Electromagnetics in Advanced Applications (ICEAA), Torino, Italy, September 12-16, 2011

Arne Schröder, Heinz-D. Brüns, Christian Schuster
Exploiting Planes of Magnetic Symmetry in the Fast Multipole Method
International Symposium on EMC Europe, Wroclaw, Poland, September 13-17, 2010

Arne Schröder, Miguel Astner, Heinz-D. Brüns, Christian Schuster
Ausnutzung magnetischer Symmetrie bei der numerischen Analyse von Feldproblemen mit der schnellen Multipolmethode
Internationale Fachmesse für elektromagnetische Verträglichkeit (EMV Düsseldorf) March 09.-11., 2010

Development of a Full-Wave Module for the High Intensity Radiated Field (HIRF) Synthetic Environment

EU-Project. 01.12.2008 – 13.05.2013

The “HIRF Synthetic Environment”, financed by the EU with a total of 45 partners, research project had the goal to provide a numerical modelling framework to the aeronautic industry which can be used during the development phase of aircraft for prediction of adequate electromagnetic immunity. For this purpose several state-of-the-art computational electromagnetic codes were integrated into a common modeling platform and validated against each other and against measurements. From the part of the Institute of Electromagnetic Theory the MoM code CONCEPT-II could be successfully adapated and integrated into the synthetic environment.

In the future, the availability of such a HIRF Synthetic Environment framework becomes more and more significant in order to be able to cope with competing requirements of new designs, with the related increase of testing, and the general demand of costs and time reductions.


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Surface current distribution on aircraft due to HIRF illumination calculated by CONCEPT-II (Source: TET, TUHH).

Further Information:

http://cordis.europa.eu/project/rcn/89387_en.html