Some aspects of shielding effectiveness related to measurements and simulations

Abstract

Two aspects of the shielding effectiveness of an enclosure are addressed: characteristics of the material of the shield and the leakage through apertures and grids. In both cases a suitable measurement set-up is presented, which enables to concentrate on the aspect under study: a TEM-t cell to characterize a thin sheet of conducting material, a dedicated test enclosure with removable front panel to study the effect of apertures. These configurations are also simulated with 3D full wave field solvers and suitable equivalent circuits are derived. The numerical results help to interpret the measurement procedure and confirm the measured results. The equivalent circuits provide fast and approximate, but still accurate enough answers to the EMC designer.