Influence of the cavity resonance on shielding effectiveness of perforated shielding boxes

This paper deals with the cavity resonance of perforated shielding boxes, which decrease shielding effectiveness. Shielding effectiveness is very important part of electromagnetic interference (EMI) - the properly designed shielding box eliminates undesired interference from the electric equipment which is placed into the box (power converters, control unit). In this paper, the illustrative example of numerical modeling of the cavity resonance of the perforated shielded box is shown and various methods for results evaluation are described. The results of simulations are confirmed by measurement.