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.
Hao Jianhong,Jiang Luhang,Fan Jieqing等. Electromagnetic Topology Model for the Shielding Effectiveness of an Apertured Enclosure with a Lossy Dielectric Layer[J]. Transactions of China Electrotechnical Society, 2017, 32(9): 101-111.
[1] 黎鹏,黄道春,阮江军,等.柱上开关开断对二次智能设备的电磁干扰研究[J].电工技术学报,2015,30(8):27-37. Li Peng,Huang Daochun,Ruan Jiangjun,et al.The EMI study of pole-mounted switch's breaking on its secondary smart devices[J].Transactions of China Electrotechnical Society,2015,30(8):27-37. [2] 吴刚,程中普,郝申军.智能变电站过程层网络中开关量多设备共享应用方案研究[J].电力系统保护与控制,2015,43(10):144-148. Wu Gang,Cheng Zhongpu,Hao Shenjun.Application scheme of intelligent substation switch value multi-device sharing[J].Power System Protection and Control,2015,43(10):144-148. [3] 秦红霞,武芳瑛,彭世宽,等.智能电网二次设备运维新技术研讨[J].电力系统保护与控制,2015,43(22):35-40. Qin Hongxia,Wu Fangying,Peng Shikuan,et al.New technology research on secondary equipment operation maintenance for smart grid[J].Power System Protection and Control,2015,43(22):35-40. [4] 郭宏光,吴庆范,黄金海,等.特高压直流输电线路间电磁耦合对电压突变量保护影响的研究[J].电力系统保护与控制,2015,43(18):114-119. Guo Hongguang,Wu Qingfan,Huang Jinhai,et al.Study on the influence of electromagnetic coupling of UHVDC power transmission lines on the voltage derivation protction[J].Power System Protection and Control,2015,43(18):114-119. [5] 谢莉,赵录兴,陆家榆,等.有限长高压直流输电线路无线电干扰电磁场的计算方法研究[J].电工技术学报,2016,31(1):96-102. Xie Li,Zhao Luxing,Lu Jiayu,et al.Study on the calculation method for radio interference electromagnetic field of HVDC transmission line with finite length[J].Transactions of China Electrotechnical Society,2016,31(1):96-102. [6] Dehkhoda P,Tavakoli A,Moini R.An efficient and reliable shielding effectiveness evaluation of a rectangular enclosure with numerous apertures[J].IEEE Transactions on Electromagnetic Compatibility,2008,50(1):208-212. [7] 郝建红,公延飞,范杰清,等.一种内置条状金属板的双层金属腔体屏蔽效能的理论模型[J].物理学报,2016,65(4):11-18. Hao Jianhong,Gong Yanfei,Fan Jieqing,et al.An analytical model for shielding effectiveness of double-layer rectangular enclosure with inner strip-shaped metallic plate[J].Acta Physica Sinica,2016,65(4):11-18. [8] 阚勇,闫丽萍,赵翔,等.基于电磁拓扑的多腔体屏蔽效能快速算法[J].物理学报,2016,65(3):1-12. Kan Yong,Yan Liping,Zhao Xiang,et al.Electromagnetic topology based fast algorithm for shielding effectiveness estimation of multiple enclosures with apertures[J].Acta Physica Sinica,2016,65(3):1-12. [9] Jiao Chongqing,Zhu Hongzhao.Resonance suppression and electromagnetic shielding effectiveness improvement of an apertured rectangular cavity by using wall losses[J].Chinese Physics B,2013,22(8):11-16. [10] 黄辉敏,张卫东,李继琨,等.含有介质板的有孔矩形腔体耦合特性分析[J].信息与电子工程,2012,10(2):161-164. Huang Huimin,Zhang Weidong,Li Jikun,et al.Coupling characteristics analysis of rectangular cavity with substrates[J].Information and Electronic Engineering,2012,10(2):161-164. [11] 杨楠.双层加载电路板屏蔽腔屏蔽效能研究[J].现代电子技术,2013,36(22):5-9. Yang Nan.Study on shielding effectiveness of double-layer metallic enclosure with load print circuit[J].Modern Electronics Technique,2013,36(22):5-9. [12] Bahadorzadeh M,Bolandpour H.Elimination the resonance of a rectangular enclosure with aperture[C]//31st International Review of Progress in Applied Comput-ational Electromagnetics,Williamsburg,Virginia,2015:1-3. [13] Nie Baolin,Du Ping’an.Electromagnetic shielding performance of highly resonant enclosures by a combination of the FETD and extended Prony’s method[J].IEEE Transactions on Electromagnetic Compatibi-lity,2014,56(2):320-327. [14] Solin J R.Formula for the field excited in a rectangular cavity with a small aperture[J].IEEE Transactions on Electromagnetic Compatibility,2011,53(1):82-90. [15] 范杰清,郝建红,柒培华.基于扩展传输线法的异型腔电场屏蔽效能[J].电工技术学报,2014,29(5):228-233. Fan Jieqing,Hao Jianhong,Qi Peihua.Electric field shielding effectiveness of heterotypic enclosures based on adjusted transmission line method[J].Transactions of China Electrotechnical Society,2014,29(5):228-233. [16] 罗静雯,杜平安,任丹,等.一种基于BLT方程的孔缝箱体屏蔽效能计算方法[J].物理学报,2015,64(1):11-18. Luo Jingwen,Du Ping’an,Ren Dan,et al.A BLT equation-based approach for calculating the shielding effectiveness of enclosures with apertures[J].Acta Physica Sinica,2015,64(1):11-18. [17] 焦重庆,牛帅,李琳.复合材料工频电场和工频磁场屏蔽效能实验研究[J].电工技术学报,2015,30(10):1-6. Jiao Chongqing,Niu Shuai,Li Lin.Experiment study of power frequency electric and magnetic shielding effectiveness for composite materials[J].Transactions of China Electrotechnical Society,2015,30(10):1-6. [18] Jongjoo S,Dong G K,Jong H K,et al.Circuital modeling and measurement of shielding effectiveness against oblique incidence plane wave on apertures in multiple sides of rectangular enclosure[J].IEEE Transactions on Electromagnetic Compatibility,2010,52(3):566-577. [19] 刘备,刘强,阚勇,等.基于传输线等效法的双层腔体屏蔽系数快速算法[J].强激光与粒子束,2015,27(5):31-37. Liu Bei,Liu Qiang,Kan Yong,et al.Fast prediction algorithm for shielding effectiveness of double enclosures based on transmission line equivalent circuit method[J].High Power Laser and Particles Beams,2015,27(5):31-37. [20] Thomas D W P,Denton A,Konefal T,et al.Characterization of the shielding effectiveness of loaded equipment enclosures[C]//International Conference and Exhibition on Electromagnetic Compatibility,York,1999:89-94.
2017, Vol. 32 
