Fast shielding effectiveness evaluation of a thin wall rectangular enclosure with numerous small circular apertures

In this paper, an extremely fast technique is introduced to evaluate the shielding effectiveness os a thin-wall rectangular enclosure with numerous circular small apertures. The technique is based on the traditional waveguide circuit model where the enclosure is replaced with an equivalent shorted transmission line. In the proposed circuit model, the perforated thin wall is replaced by a proper equivalent impedance that is derived from the reflection coefficient. The computation results are in very good agreement with measurements. Besides accuracy, the method is extremely efficient and easy to implement compared to the numerical techniques.