有孔双层屏蔽腔体的宽频带屏蔽效能

 用扩展为可分析腔内高次模的传输线方法研究了有孔双层屏蔽腔体的屏蔽效能，该方法可以考虑腔内较宽的频带范围。计算了双层屏蔽腔内电场的屏蔽系数，与单层屏蔽腔内屏蔽系数的比较表明,采用双层屏蔽使得腔体的屏蔽效能大为提高。分析了双层屏蔽腔体孔缝耦合的共振效应、腔内的谐振。结果表明：满足共振效应成立条件时双层屏蔽腔内也发生共振现象，屏蔽效能在共振频率附近明显降低；在腔内的谐振点屏蔽系数出现极小值，此时屏蔽效果较差；在0.1~4.5 GHz的范围内，屏蔽系数随着频率的增加总体上呈下降趋势。

Shielding effectiveness of double layer rectangular enclosure with aperture to wide band electromagnetic pulse

The transmission line method(TLM) is extended to include higher-order transverse electric(TE) cavity modes which are introduced by aperture coupling and the extended TLM is used to analyze the shielding effectiveness(SE) of double layer rectangular enclosure with apertures to the wide band electromagnetic pulse. The electric SE of single layer with an aperture is compared with that of double layer with apertures. The simulation results show that SE can be improved greatly with double layer shielding and it is worse on the resonance frequency of cavity modes. On the condition of aperture-cavity resonance, SE drops significantly in the center of the inner cavity. From 0.1 GHz to 4.5 GHz, SE has a declining trend as a whole.