Electric and magnetic shielding effectiveness of metallic enclosures with apertures

This paper presents a detailed study of the shielding effectiveness of a rectangular metallic enclosure with apertures by using an analytical formulation and experimental study. The theories developed by other researchers have been extended to take into account the contribution of multimode of propagation in the enclosure. Both the electric and magnetic shielding effectiveness were calculated as a function of frequency, enclosure dimensions, aperture dimensions, various aperture positions and observation points by employing a transmission line equivalent circuit approach. Simple modifications were included to account for multiple apertures. Generally, the analytical results of the shielding effectiveness are in good agreement with measurement results which were conducted in a GTEM cell.