有孔腔体屏蔽效应分析的混合模型  

Hybrid model to evaluating shielding effectiveness of cavity with apertures

作　　者：张旭锋[1] 李颖[1] 倪谷炎[1] 罗建书[1] 

机构地区：[1]国防科技大学理学院,湖南长沙410073

出　　处：《电波科学学报》2011年第1期25-29,共5页Chinese Journal of Radio Science

基　　金：国家自然科学基金(10871231);武器装备预研基金(9140A31020609KG0170)

摘　　要：对于带矩形孔缝的矩形腔,利用传输线模型求得孔缝上的近似电场,并以此为等效磁流,利用腔体中的并矢格林函数,估算腔体中的耦合场强与屏蔽效应,并推广到孔缝偏离中心的情形。数值结果与其他方法以及实测值吻合的很好,验证了方法的有效性。分析了孔缝偏离中心、孔缝尺寸变化、平面波斜入射时的屏蔽效应,数值结果表明:孔缝偏离中心使腔体中心点屏蔽效应增大,腔体尺寸相同,孔缝越大屏蔽效应越小,孔缝长度增加会使谐振频率发生偏移和加宽;屏蔽效应随入射角或极化角的增大而增大。A transmission line/Green function hybrid model to evaluating the shielding effectiveness of cavity with apertures is presented. The electric field on the aperture is calculated by the transmission line model, which is used as the equivalence magnetic current source to evaluate the field and shielding effectiveness inside the cavity by the dyadic Green function, then this model is generalized to evaluate the shielding effectiveness of cavity with off-center apertures. Numerical results are in good agreement with other methods and measured data. The results indicate that the shielding effectiveness at the center of cavity with off-center aperture is better than that with center aperture; the larger the aperture is, the worse the shielding effectiveness willbe; as the aperture length becomes longer, the resonance is broader; the shielding effectiveness increases when the incidence angle or polarization angle increases.

关 键 词：电磁兼容 屏蔽效应 孔缝 传输线 格林函数 

分 类 号：O441.5[理学—电磁学]