Modified estimation of shielding efficiency for hole

For reduction of the impact of electromagnetic field on parameters of electronic equipment, shielding in many different shapes and qualities is used. The quality of the shielding is dependent on size, shape and amount of openings in the body of the shield. In electromagnetic immunity and emission tests it is very difficult to predict the shielding efficiency from theory of refraction, reflection and diffraction due to the very complicated shape and material mix in the design configuration of multilayer PCB, supports, covers and screens. For this reason in order to build up and make calculations of scattering matrix parameters as the estimation of the shielding efficiency in the given frequency range we propose to use the drawn 3D electromagnetic model.