A fast shielding effectiveness calculation of rectangular enclosures with arbitrary shape apertures

A fast method of moments (MoM) solution of surface electric field integral equation (EFIE) is employed to evaluate the electromagnetic wave coupling inside metallic enclosures, due to presence of arbitrary shape slots. In this paper, we propose an appropriate numerical integration technique in order to reduce the MoM impedance matrix calculation time without compromising accuracy. The technique is used to compute integrals resulting from MoM for the frequencies above the cavity first resonance. Within this frequency range, the wave penetration inside the enclosure is high and so one can avoid unnecessary high accuracy integrations. Regarding this new technique, the shielding effectiveness of an enclosure is evaluated efficiently in a wide range of frequency. The accuracy of the method is demonstrated by a number of examples.