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International audience; Transfer impedance is a main characteristic to describe the shielding performance of shielded cables at least up to 1 GHz. Traditionally, methods like line-injection and triaxial cell have been used to characterize it at ambient laboratory conditions. While the ambient laboratory conditions might represent appropriate environmental conditions for some industries, in others, like automotive, they are only a small subset of the real conditions. Thus, there is a need to characterize the transfer impedance over different environmental conditions. In this article, the authors present and verify a new triaxial cell design that is aimed to provide reliable measurements during high thermal and mechanical stresses. First, the cell performance is compared to a commercial cell at laboratory ambient conditions. Then, measurements are performed with the new cell at highly accelerated life testing conditions. Under these high thermal and mechanical stress conditions the cell performance is verified, and results on typical shielded cable performance under the same conditions are given.

International audience; Transfer impedance of shielded cables is a main characteristic to describe cable shielding performance at least up to 1 GHz. Traditionally, a cable shield consists of a braid, a foil, or a combination of them. Braids have attracted a significant amount of research interest, while foils have not. Published studies have concentrated on cable shielding performance when cables are new. In this paper, a highly accelerated aging method for shielded cables is presented and applied to a cable made up of a combination of a braid and foil shield. Finally, the effect of aging on system performance during bulk current injection (BCI) tests is assessed by circuit simulation.

International audience; Triaxial measurement is an effective means to determine the transfer impedance of a shielded cable. It is based on coupled transmission line principle. In an ideal case, both transmission lines in the setup would be matched to guarantee the high frequency performance. In practice, matching is hard to achieve without compromising on usability and generality of the measurement setup. This paper discusses how triaxial cell diameter and the resulting impedance mismatch affects transfer impedance measurement results. In addition, the paper shows how impedance mismatches can be modeled, presents a simplified model to quickly understand the effects of impedance mismatch, and compares the model to results measured with different triaxial cell sizes. The simple model presented achieved similar accuracy to a more complex model defined in IEC 62153.

Designing of low-cost and more compact electromagnetic interference (EMI) filters must be achieved by considering intercomponent coupling. Actually, magnetic coupling, arising from the proximity of the components constituting the filter, has a major influence on the filter performance. The aim of this paper is to present a methodology for filter design, which takes into account intercomponent coupling and, therefore, can predict filter attenuation very accurately, whatever the structure and the topology of the filter may be.

Le filtrage antiparasite des circuits electroniques permet de reduire les perturbations conduites associees. Ces filtres sont dimensionnes pour rendre un equipement electronique conforme aux normes regissant la compatibilite electromagnetique. Dans cet article, le phenomene de propagation de bruit dans un equipement electronique / electrique est aborde. Le filtre pour la compatibilite electromagnetique est alors decrit ainsi que l’attenuation, sa propriete principale. Sont ensuite presentes les structures de filtres typiques, ainsi que la modelisation des composants passifs le constituant, et les parametres influant sur les performances d’un filtre.

The design of cheaper and more compact electromagnetic compatibility (EMC) filters can be achieved by exploiting the magnetic coupling between components. This requires the knowledge of coupling coefficients between components and, consequently, of their equivalent coupling surface. The aim of this paper is to present how this coupling surface can be determined using a transverse electromagnetic mode cell. This methodology is described and applied to two different cases: a capacitor and an inductor. In order to validate the determination and usage of equivalent coupling surfaces, a comparison between the calculation and measurement of mutual inductances is carried out on practical examples.

Filter design heavily depends on magnetic inter-component couplings. To determine the magnetic coupling, i.e. the mutual inductance between two components, it is necessary to define a coupling model, in order to figure out to which extent a component catches the magnetic field. The coupling model of complex components, such as common mode chokes, cannot be established directly from geometry because of the number of ports, the possible modes (common and differential) and the magnetic material. This paper presents a procedure to determine the coupling model of common mode chokes using a TEM (Transverse ElectroMagnetic) cell.

International audience; In filter design, inter-component parasitic couplings play a major role in the filter response. Most often, filter designers try to minimize these couplings through a proper implementation of components; conversely, this paper aims to optimize filter responses through a clever use of these couplings. Previous works have been performed to reach such an objective ([1]-[2]), focusing on the study of LC filters with 3D simulation or PSpice techniques. Moreover, the MKME method has been identified as a promising technique in many design cases. The objective of this paper is to introduce the application of the MKME method to an LC filter, to validate its use and benefits, before deploying it for more complex filter structures.