Electromagnetic shielding effectiveness of rectangular enclosure with perforated walls

A numerical method is presented to determine the electromagnetic shielding effectiveness of a rectangular box with perforated walls. Expressing electromagnetic (EM) fields in terms of cavity Green´s function inside the box and free space Green´s function outside the box, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential magnetic field across the apertures. Using the Method of Moments (MoM), the integral equations are solved for unknown aperture fields. From a knowledge of the aperture fields, the EM field inside a rectangular box with perforated walls due to external EM sources are determined. Numerical data of EM shielding effectiveness of a rectangular box with a single aperture and multiple apertures is presented and validated with experimental and earlier published data