Near-zone electromagnetic interference estimation for shielding effectiveness of apertured rectangular enclosure

This paper presents an equivalent circuit approach to evaluate the effect of near-zone electromagnetic interference on the shielding effectiveness (SE) of an apertured rectangular enclosure. The approach is an extension of Robinson´s equivalent circuit formulation. The extension in this paper is carried out by using an electric dipole to represent the external interference and applying the electric field at the aperture caused by the dipole to replace Robinson´s incident plane wave. The SE correlates to the dimensions of the enclosure and the aperture. The distance from the interference to the enclosure and the observed position within the enclosure are significant parameters on the SE evaluation. The shapes of the aperture also affect the SE. This equivalent circuit approach based on the available analytical formulation provides a fast means of investigating the effect of design parameters on the SE of an apertured enclosure for near-zone interference and can be used for designers of shielded enclosures.