含孔缝金属腔体电磁场增强效应的形成机理仿真  

Formation Mechanism Simualtion of Electromagnetic Field Enhancement Effect of Metallic Shielded Enclosure with Aperture

作　　者：魏光辉[1] 李凯[1,2] 潘晓东[1] 张龙[1] 李新峰[1] 

机构地区：[1]军械工程学院静电与电磁防护研究所 [2]武汉军械士官学校教练勤务团

出　　处：《高电压技术》2014年第6期1637-1643,共7页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(6131380301)~~

摘　　要：为分析金属腔体场强增强效应,保护腔体内部敏感电路,采用电磁仿真软件CST,从频域角度利用屏蔽效能对其开展仿真研究,并利用矢量网络分析仪、功率放大器、GHz横电磁波传输室和脉冲强磁场测量探头搭建实验系统进行了验证。最后理论分析了场强增强效应的形成机理,研究了孔缝形状、电磁波极化方向、腔体不同位置、吸波材料加载对场强增强效应的影响规律。仿真和实验结果有较好的一致性,结果表明:腔体孔缝增强效应受到腔体表面电流、孔缝谐振和腔体谐振的影响;矩形孔缝的场强增强效应比方形、圆形孔缝显著;电磁波极化方向垂直于矩形孔缝长边的场强增强效应最强;在最小谐振频率以下,孔缝中心轴线上离孔缝越近增强效应越显著,并且加入吸波材料能较好地减弱腔体中心的场强增强效应。研究结果为含孔缝腔体的电磁兼容设计与防护提供了理论依据。For protecting sensitive circuits in shielded enclosures, we analyzed the enclosures enhancement effect of field intensity using the software CST. Then we verified the simulation results though experiments in a homemade experimental system composed of a vector network analyzer, power amplifiers, a giagahertz transverse electromagnetic chamber, and pulsed electromagnetic field measuring probes, etc. Lastly we theoretically analyzed the mechanism of the field enhancement, and the influences of the aperture shape, the electromagnetic wave＇s polarization direction, the position in cavity, and the absorbing material loaded on the enhancement. It is shown that the simulation agrees with the experiment results. The field enhancement effect of aperture is affected by the enclosure＇s surface current, the aperture resonance, and the enclosure resonance. The effect is more remarkable if the aperture is rectangular, compared with square or circular apertures. For different polarization directions of the electric field, the electric field perpendicular to the long side of rectangular aperture results in the strongest enhancement effect. The enhancement effect strengthens with decreasing distance to the aperture when the frequency is below its minimum resonant value. Moreover, adding absorbing materials can fairly weaken the enhancement effect at the center of the enclosure. The results can be a theoretic basis for electromagnetic compatibility designs and protections for shielded enclosures with apertures.

关 键 词：屏蔽效能 场强增强效应 屏蔽腔体 孔缝 电磁兼容 电磁防护 CST仿真 

分 类 号：TN03[电子电信—物理电子学]