为了分析带有孔缝双层金属机壳的屏蔽效能,采用广义散射矩阵级联的思想,将多层金属腔体近似等效为若干个能够传输多个模式的波导级联,提出了一种使用模式匹配法和基于矩量法求解混合位积分方程的全波混合算法。该算法考虑了腔体结构、孔缝排列形式、入射波极化方向以及高次模等因素对屏蔽效能的影响。通过将数值仿真结果与经典算法仿真结果进行对比,验证了其具有较高的准确性和有效性。研究结果表明：双层金属腔体的屏蔽效能要优于单层金属腔体的屏蔽效能,适当地增加双层金属腔体上孔缝所在侧壁之间的距离可以提高屏蔽效能,当双层金属腔体侧壁上的孔缝平行排列时,平行极化下的屏蔽效能要优于垂直极化下的屏蔽效能,而当孔缝交叉排列时,平行极化和垂直极化下屏蔽效能的优劣则并不明显。

This paper proposes a rigorous full-wave solution which combines the mode-matching technique and the mixed potential integral equation based on the method of moments to analyze the shielding effectiveness of the metallic rectangular cascaded enclosure with apertures. Some influence factors, such as the dimension of enclosures, the orientation of apertures, the polarization direction of the incident wave and the high-order modes propagating in enclosures, are considered. The accuracy and the efficiency of the proposed approach are validated by comparing with the classical algorithm. Finally, some conclusions are derived: the shielding performance of cascaded enclosures is better than that of single-stage enclosures, the shielding effectiveness can be improved with increasing the distance between stages in the range, and the shielding performance of the double-stage enclosure with parallel-pattern apertures in horizontal polarization case is better than that in vertical polarization case, but similar advantage is not obvious for enclosures with cross-pattern apertures.