平面波照射下开孔矩形腔体的电磁耦合与屏蔽效能研究

Electromagnetic coupling and shielding effectiveness of apertured rectangular cavity under plane wave illumination

基于Bethe小孔耦合理论和腔内电磁场的本征模展开,建立了平面波照射下开孔矩形腔体电磁场分布的近似解析模型.该模型物理意义清晰,可以考虑开孔的形状、尺寸、个数及位置和入射波的传播与极化方向等参数的影响.该模型的计算结果优于传统的等效电路方法,与实验结果的一致性更好.计算分析了相关因素对电磁屏蔽效能的影响规律,所得结果对电磁屏蔽腔体的设计有指导意义.

Based on the Bethe＇s theory for small aperture coupling and the eigen-mode expansion method, an approximate analytic model for the field distribution inside a rectangular cavity with apertures under plane wave illumination is presented. The effects of aperture shape, dimensions, number, position, and the wave incidence and polarization angles on cavity mode excitation can be taken into consideration in this model with clear physical explanation. The calculation results from this model are in better agreement with experimental data than those from the equivalent circuit model. The effects of various factors on the shielding effectiveness of the cavity are analyzed, and the obtained results are useful for guiding the design of electromagnetic shielding enclosures.