Analysis of the Shielding Effectiveness of a Slotted Shield

The aim of this paper is to present an effective analytical approach in order to perform the analysis of the decrease of the shielding performances of a metallic shield, in terms of the shielding effectiveness, when a slot aperture is introduced. In fact the shielding performances of a real shield including apertures are usually completely defined by the presence of the considered aperture rather than by the solid part of the shield. In this paper the main idea is to show how it is possible to get a closed form solution to the considered problem through the development of a more general analytical approach that even let us consider the possible presence of any kind of linear stratified structure as loading medium in the shielded volume. In order to do that the double spatial Fourier transform is introduced, leading to a suitable formalism in the spectral domain rephrasing the electromagnetic problem in an equivalent circuit network model problem. The circuit network approach in the spectral domain yields a sort of Wiener-Hopf equation that can be analytically solved, through a suitable extended version of the Wiener-Hopf approach, or numerically faced and iteractively solved with the requested accuracy through the Method of Moments in the spectral domain.