An efficient analytical method based on the Cohn model and mirror procedure is proposed for the prediction of the shielding effectiveness (SE) of a rectangular enclosure with electrically large apertures. Firstly, the coupled electromagnetic fields are represented by the equivalent dipole moments located at the centre of the aperture according to the Cohn model, where the dipole moments can be calculated based on the mirror procedure. Then, the vector potentials can be obtained through the relation between the dipole moments and the current distribution. Finally, the total electric fields are obtained by using the vector potentials, thus the SE and most of the resonant modes can be predicted accurately and fast. The SE results which have been verified by the CST over a wide frequency band of 0.01–3.0 GHz show that the proposed method is effective in handling the enclosure with electrically large apertures, including the multiple apertures arranged in different ways and hybrid apertures in different shapes and dimensions.

中文翻译：

---

基于Cohn模型和镜像程序的具有大电孔径的外壳的屏蔽效率的有效方法

提出了一种基于Cohn模型和镜像程序的有效分析方法，用于预测电大孔径矩形壳体的屏蔽效率（SE）。首先，根据Cohn模型，耦合电磁场由位于孔径中心的等效偶极矩表示，其中偶极矩可以基于镜像过程进行计算。然后，可以通过偶极矩与电流分布之间的关系获得矢量电势。最后，通过使用矢量电势获得总电场，从而可以准确，快速地预测SE和大多数谐振模式。SE结果已由CST在0.01-3的宽频带上进行了验证。