Guillaume Andrieu

Extension of the “Equivalent Cable Bundle Method” for Modeling Electromagnetic Emissions of Complex Cable Bundles

This paper presents an extension of the so-called ldquoequivalent cable bundle methodrdquo for the computation over a large frequency range of the electromagnetic radiation of complex cable bundles. The purpose of the method is to reduce the complexity of the problem by grouping together the conductors according to their terminal load configuration and their excitation to reduce the required computation time for the complete cable bundle modeling. As far as the use of the method on emission problems is concerned, a new five-step procedure is established to define the electrical and geometrical characteristics of the reduced cable bundles. After the description of the adjustments required for the application of the method to emitting cases, some numerical and experimental validations performed on simple cable bundles illustrate the efficiency and the advantages of the method. The research described in this paper is considered as a new step in the study of the modeling of complex cable bundles at ldquohigh frequenciesrdquo.

On the Low-Frequency Optimization of Reverberation Chambers

An original method allowing to define a particular frequency called “quasi-ideal reverberation chamber (RC) minimum frequency” is presented. This frequency corresponds to the frequency where an RC is considered as working in a “quasi-ideal regime.” According to the definition of an ideal RC, the method is based on the assessment 1) of the electromagnetic (EM) field distributions obtained in the working volume (in comparison with the distributions obtained in the ideal model defined by Hill [D. A. Hill, “Plane wave integral representation for fields in reverberation chambers,” IEEE Trans. Electromagn. Compat., vol. 40, no. 3, pp. 209--217, Aug. 1998.]) and 2) of the number of uncorrelated samples obtained over one mode stirrer revolution. The method is considered as helpful in order to optimize the functioning of an RC at low frequencies for broadband EM compatibility immunity and emission tests. Indeed, it is shown from experimental and numerical results that the insertion of an optimal loading in the chamber allows to decrease the frequency where the chamber works quasi-ideally. The influence of complexifying the mode stirrer geometry is also discussed.

Investigations about the Use of Aeronautical Metallic Halls Containing Apertures as Mode-Stirred Reverberation Chambers

The possibility to use aeronautical metallic halls (AMHs) equipped with a mode stirrer as mode-stirred reverberation chambers (MSRCs) is investigated. The objective is to study the ability of these facilities to generate an electromagnetic environment equivalent to an MSRC in spite of the apertures linking the inner and the outer environment. In particular, the objective is to check if a sufficient number of independent positions of the mode stirrer can be obtained and if the energy storage can be sufficient within these facilities. Encouraging experimental and numerical results, respectively, obtained on a real AMH and calculated with full-wave method on prototype halls are presented and discussed.

Homogenization of Composite Panels From a Near-Field Magnetic Shielding Effectiveness Measurement

A simple method permitting to obtain a homogeneous panel from a strongly inhomogeneous panel is presented. The method consists of determining the characteristics of a panel having an equivalent conductivity obtained from a near-field magnetic shielding effectiveness measurement. Thus, the method suitable for frequencies lower than 1 MHz does not require the knowledge of the detailed internal geometry of the sample. After the validation of the measurement setup on a copper plate of known conductivity, two space composite panels are characterized and homogenized.

The 'Equivalent Cable Bundle Method': an Efficient Multiconductor Reduction Technique to Model Industrial Cable Networks

In automotive electromagnetic (EM) compatibility (EMC), the cable bundle network study is of great importance. Indeed, a cable network links all the electronic equipment interfaces included the critical ones and consequently can be assimilated both to a reception antenna and to an emission antenna at the same time. On the one end, as far as immunity problem is concerned, where an EM perturbation illuminates the car, the cable network acts as a receiving antenna able to induce and propagate interference currents until the electronic equipment interfaces and potentially induce dysfunction or in the worst case destruction of the equipment. At low frequency, the interference signal propagating on the cable network is generally considered as more significant than the direct coupling between the incident field and the equipment. On the other end, as far as emission problem is concerned, the EM field emitted by the cable network may disturb itself the electronic equipments by direct coupling. To avoid these problems, automotive manufacturers have to perform normative tests before selling vehicles. These tests are applied on electronic equipments outside and inside the car first to verify that the equipments are not disturbed by an EM perturbation of given magnitude and second to ensure that the EM emission of each equipment does not exceed a limit value at a given distance. Obviously, these tests are not exhaustive and fully representative of real conditions. For example, in immunity tests, two polarizations (vertical and horizontal polarizations) of the EM perturbation are generally tested in free space conditions. In reality, the EM perturbation due for example to a mobile phone outside the car could happen from any direction of space and be reflected by all the scattering objects located in the close environment of the vehicle (ground, other vehicles, buildings,...). Consequently, the contribution of EM modelling is a great tool for automotive manufacturers in order to proceed to numerical normative, additional and also parametric tests at early stages of the car development on numerical models and for a reasonable cost. Moreover, numerical modelling will reduce the number of prototypes built during the

A Numerical Methodology for the Prediction of the Near-Field Parasitic Electromagnetic Emissions of Solar Panels

This paper presents a methodology that is developed to assess the parasitic electromagnetic (EM) emissions of a satellite solar panel from a quasi-static to several tens of megahertz bandwidth. In the method, the solar panel is first modeled as an equivalent electric circuit, which allows the computation of the current distribution in all the elements using Spice-like software. The model is then converted into a network of electric dipoles, which permits to calculate the total EM emissions of the solar panel at a given point by the vectorial summation of the EM emissions due to each electric dipole. Thus, only the dipolar moment and the position and the orientation of each electric dipole are required. Encouraging experimental validations performed on a prototype solar panel are presented to illustrate the efficiency and the accuracy of the method. The method described in this paper is considered as a first step required in order to prepare wider applications on real satellites in the near future.

High-Frequency BCI-Like Tests With a Stripline Injection Probe

This paper presents an innovative and compact injection system able to extend the possibility to perform bulk current injection (BCI) tests until 2 GHz (at least). The proposed structure is a Stripline injection cell ensuring the propagation of a progressive transverse electromagnetic wave (TEM). Within the structure, the victim cable is exposed to a tangential electric field of high amplitude corresponding to the TEM wave. In order to illustrate the interest and the performances of the proposed setup, a generic device under test is built. Then, when comparing the performances of the proposed system with a reverberation chamber from an immunity test point of view, it is shown that the proposed setup obtains similar performance until 2 GHz, in particular when comparing the power required to obtain a failure of the device under test. Due to its simple geometry, the proposed injection system is easy to model with a full-wave EM solver and does not present any nonlinear effect, two important advantages in comparison to classical toroidal magnetic probes used in BCI tests.

The EOLES project

The EOLES (Electronics and Optics e-Learning for Embedded Systems) project is a 3-year joint project involving 15 institutions, four from Europe and eleven from the North African countries of Algeria, Morocco, and Tunisia, whose aim is to create a 3rd year Bachelor degree in Electronics and Optics for Embedded Systems. The project started in October 2012 and is scheduled to end in October 2015. One of the biggest challenges to a full implementation of an e-learning course in engineering is the laboratories. They are unanimously recognized as essential in any engineering course. Contrary to the majority of engineering courses that force students to attend on-site hands-on labs sometime along the course, EOLES students will be able to perform their lab duties online. Indeed, the most innovative aspect of this project is precisely the implementation of a remote laboratory that will enable students to carry out remotely the practical works associated to each technical unit within the course.

Low-frequency characterization of composite panels from a near-field magnetic shielding effectiveness measurement

This paper presents a simple method allowing to obtain an homogeneous panel model from an inhomogeneous composite panel thanks to a near-field magnetic shielding effectiveness (MSE) measurement in the low frequency range (f <; 1 MHz). The method, which does not require the knowledge of the detailed internal geometry of the panel, consists in determining the “equivalent conductivity” of the homogeneous model. After the validation of the measurement setup on a copper plate of known conductivity, homogenization of 3 different samples is presented. Finally, homogenization of samples made of different inhomogeneous layers previously characterized separately is presented and validated.

Determination of the “quasi-ideal reverberation chamber minimum frequency” according to the mode stirrer geometry

An original method allowing to define from measurements a specific frequency called “Quasi-Ideal Reverberation Chamber Minimum Frequency” (QIRCMF) is presented. This frequency corresponds to the frequency where a mode stirred reverberation chamber starts to work “quasi-ideally”. The method is based on 1) the assessment of the electromagnetic field distributions obtained in the working volume (in comparison with the distributions obtained in the ideal model defined by Hill [1]) and 2) the number of uncorrelated samples obtained over one mode stirrer revolution. Experimental results clearly show that the QIRCMF is reduced by increasing the mode stirrer geometry in particular when the reverberation chamber works at its optimal Q-factor. Original results corresponding to the influence of the mode stirrer geometry on the EM field distributions obtained in the working volume for different Q-factors of the facility are also presented.