The Effect of Apertures Position on Shielding Effectiveness of Metallic Enclosures based on Modal Method of Moments

In this study, an effective numerical method suitable for determination of electric field Shielding Effectiveness (SE) of rectangular enclosure with multiple rectangular apertures is presented. Assuming appropriate electric field distribution on the aperture, Electromagnetic fields inside the enclosure are determined using rectangular cavity Green’s function. Electromagnetic fields outside the enclosure and scattered due to the aperture are obtained using the free space Green’s function. Matching the tangential magnetic field across the apertures, the integral equation with aperture fields as unknown variables is obtained. The integral equation is solved for unknown aperture fields using the Method of Moments. From the aperture fields the electromagnetic SE of the rectangular enclosure is determined. The numerical results of the proposed technique are in very good agreement with data available in the literature and experimental results. It is shown that apertures’ position and shape, aperture’ number, polarization have noticeable effect on the electric field SE.