Electromagnetic modeling of semi-anechoïc chamber between 30 and 200 MHz

International audienceThis paper addresses EMI (ElectroMagnetic Interference) chamber performance in the frequency range between 30 and 200MHz, which is where chambers exhibit their deficiencies. The difference between attenuation in an open area test site (OATS), called Normalized Site Attenuation (NSA) and this same measure in the test chamber gives the performances. The European EN50147-2 and American ANSI C63-4 standards authorize a maximum deviation of ± 4 dB. Numerical modelling enables us to identify performances and thus optimise the chamber. In this work, we propose a whole new chamber modelling with a boundary condition taking into account the reflectivity of ferrite tile. Also we focus on antenna modelling because of the significant mutual coupling effect in this frequency range, unlike other previous works which consider electrically small antennas