Abstract：An electromagnetic topology (EMT) model for the shielding effectiveness (SE) of an apertured rectangular metallic enclosure with a lossy dielectric layer against an oblique incident plane wave is established according to the EMT theory and BLT equation. The approximate analytical formulas of the SE are derived, and the effect of various factors including the thickness, the material and the position of the lossy dielectric layer, the polarization and incident angles of the plane wave on the SE is analyzed based on the EMT model. The results indicate that the lossy dielectric layer can suppress the resonance, leading to great improvement on the SE for frequencies near the resonance but almost no effect on the SE for frequencies far away from the resonance. The larger the thickness of the lossy dielectric layer is, the higher the SE will be. There exist the optimum conductivity and relative permittivity for different resonant frequencies, which leads to the strongest suppression effect and the maximum values of the SE. The SE for the lossy dielectric layer in the front of the enclosure is higher than that when it is at the back of the enclosure. The maximum values of the SE are obtained at different positions of the lossy dielectric layer for different resonant frequencies. The larger the polarization angle and the azimuth angle are, and the smaller the elevation angle is, the higher the SE will be. The results are in good agreement with those of the simulation. The proposed EMT model is much faster than the transmission line method (TLM), especially in the high frequency range, and requires less time than numerical methods and CST in calculating the SE, which is helpful for guiding the design of shielding enclosures.
郝建红, 蒋璐行, 范杰清, 公延飞. 内置介质板的开孔箱体屏蔽效能电磁拓扑模型[J]. 电工技术学报, 2017, 32(9): 101-111.
Hao Jianhong, Jiang Luhang, Fan Jieqing, Gong Yanfei. Electromagnetic Topology Model for the Shielding Effectiveness of an Apertured Enclosure with a Lossy Dielectric Layer. Transactions of China Electrotechnical Society, 2017, 32(9): 101-111.
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2017, Vol. 32 
