Semi-analytical method for evaluating shielding effectiveness of an enclosure with an aperture

Abstract

The paper presents a semi-analytical method for calculating the shielding effectiveness (SE) of an enclosure with an aperture filled with a dielectric or magnetic material. The method is based on a combination of quasi-static analysis of coplanar strip lines (CPS) and an analytical model of an enclosure equivalent circuit. A simulation of a CPS is reduced to solving a simple electrostatic problem and can be performed by any available numerical method. The SE calculation can be performed using any of the existing models of an enclosure equivalent circuit. In the range up to 1 GHz, a validation of the proposed method was carried out using a standardized enclosure 300×120×300 mm3 as an example. To show the capabilities of the method, the paper presents the results of SE for enclosures with a PVC ventilation grill and a glass in the aperture. Using this method in conjunction with a previously published analytical model, the SE calculations for the enclosure with a conducting plate were also performed. The results show that the proposed method has an acceptable accuracy, and the average value of the absolute error does not exceed 6.4 dB