中文摘要：

本文研究了TLM、ILCM、Modal—MOM三种模型计算平面波照射下开孔矩形金属腔宽频带内屏蔽系数的适用性．通过比较这三种模型在0．5～3GHz范围腔体中心点处屏蔽系数的计算结果，并与CST模拟结果进行对比，发现Modal-MOM方法适合用于宽频段屏蔽系数的计算，但在高频时预测出的谐振点有明显频偏．TLM不适用于高频（电尺寸较大孔缝）计算，而ILCM方法不适用于较高频率情况和正方形孔缝的计算，且整体计算结果偏差较大．这些方法的适用范围在工程应用方面具有很好的指导意义．

英文摘要：

The applicability of three fast calculation methods for shielding effectiveness （SE） of a rectan gular cavity at a wide frequency band from 0.5 to 3 GHz has been studied. Results show that Modal MOM is suitable for SE calculation at a wide band, but the predicted resonances shows frequency offset at higher frequency. TLM is not suitable for the SE calculation at higher frequency above 1. 5GHz （namely, for electronic large apertures ）, while ILCM is not applicable for square apertures and higher frequency, and its results are not in agreement with CST well.