A hybrid FD-MoM technique for predicting shielding effectiveness of metallic enclosures with apertures

In this paper, a hybrid technique combining the finite-difference (FD) method and the method of moments (MoM) in the frequency domain is proposed to predict the shielding effectiveness of rectangular conducting enclosures with apertures under external illumination. The interior and exterior regions of the enclosure are analyzed separately by employing the field equivalence principle. Internal electromagnetic fields are discretized using the (FD) method, while external fields are formulated by the MoM. Enforcement of continuity of the tangential magnetic field over the aperture surface gives the desired equation to solve for electromagnetic fields everywhere. Numerical results for the shielding effectiveness of a rectangular cavity with apertures calculated by the new hybrid technique are presented and validated by comparing with experimental data.