高频有损斜开孔腔体屏蔽效能研究

针对带孔屏蔽腔体工作时受复杂电磁干扰问题,基于电磁拓扑理论和BLT 方程,考虑开孔倾斜、偏 心、任意平面波照射、任意观测点位置等情况,提出用于计算斜开孔腔体屏蔽效能的解析模型。同时将腔体材料考 虑为有损导体,对BLT 方程中散射矩阵和传播矩阵进行修改;并利用电压和电场分布关系,考虑腔体内多种传播模 式,将模型的可计算频段拓展为0~3 GHz。最后,设计五组试验,对比CST 仿真值、Robinson 拓展算法计算值与文中 所提模型计算值,验证所提模型的准确性与优化性。为实际工程中孔缝腔体屏蔽问题的预测与计算提供方法。

Research on the Shielding Effectiveness of a Lossy Enclosure with Oblique Openings at High Frequencies

Aiming at the problem of complex electromagnetic interference in the work of shielded enclosures with holes. Based on the electromagnetic topology theory and the BLT equation, an analytical model for calculating the shielding effectiveness of an enclosure with oblique openings is proposed, considering the situation of opening inclination, eccentricity, arbitrary plane wave irradiation, and arbitrary observation point position. At the same time, the material of the enclosure is considered as a lossy conductor, and the scattering and propagation matrices in the BLT equation are modified. The distribution relationship of voltage and electric filed is exploited to account for the various propagation modes in the enclosure in order to extend the computable frequency band of the model to 0-3 GHz. Finally, five sets of experiments are designed to verify the accuracy and optimization of the proposed model by comparing the CST simulation values, the Robinson extended algorithm calculated values and the calculated values of the proposed model. It provides a method for prediction and calculation of shielding problems of shielded enclosures with holes in practical engineering.