An Analytical Method for Calculating the Shielding Effectiveness of an Enclosure with an Oblique Rectangular Aperture

An efficient analytical method is proposed to calculate the Shielding effectiveness (SE) of an enclosure with an oblique rectangular aperture. This enclosure was first decomposed into two ones with horizontal rectangular apertures through mirror image and Green function theories. The SE of each decomposed enclosure was calculated by the Robinson's method. The relationship between the SE of the original cavity and those of the decomposed ones was also derived analytically. The SE of the original cavity could be directly obtained from this analytical relationship. The accuracy of the proposed method was validated with measurements and the Transmission line matrix (TLM) solver. The results show that the efficiency was largely improved compared with the TLM solver.