A Comparative Study on the Equivalent Coupling Surface Determination of a Film Capacitor Using Closed TEM, Open TEM, and GTEM Cells

The equivalent coupling surface (ECS) of passive components plays a key role in studying their mutual magnetic coupling phenomena. To enable an accurate prediction of electromagnetic interference (EMI) filter attenuation essentially below the range of hundreds of MHz, the consideration of these inter-component magnetic coupling phenomena becomes essential. In this paper, an in-depth comparison between the use of three transverse electromagnetic (TEM) cell variants, namely closed, open and gigahertz TEM (GTEM) cells for the determination of the equivalent coupling surface of a film capacitor is presented. Based on the comparison results of this capacitor representing a sample of tested components, this paper aims to show that whatever the used cell, the equivalent coupling surface of passive components can be determined with a good accuracy.