孔缝对金属腔体强电磁脉冲耦合特性影响研究  

Effect of aperture on shielding performance of metal cavity under excitation of high-intensity electromagnetic pulse

作　　者：曾美玲 蔡金良[2,3] 易早 秦风[2,3] 邝向军[1] Zeng Meiling;Cai Jinliang;Yi Zao;Qin Feng;Kuang Xiangjun(College of Science,Southwest University of Science and Technology,Mianyang 621010,China;Institute of Applied Electronics,CAEP,Mianyang 621999,China;Key Laboratory of Science and Technology on Complex Electromagnetic Environment,CAEP,Mianyang 621999,China)

机构地区：[1]西南科技大学理学院,四川绵阳621010 [2]中国工程物理研究院应用电子学研究所,四川绵阳621999 [3]中国工程物理研究院复杂电磁环境科学与技术重点实验室,四川绵阳621999

出　　处：《强激光与粒子束》2021年第4期35-44,共10页High Power Laser and Particle Beams

基　　金：国防预研项目(30105140302)。

摘　　要：核电磁脉冲和高功率微波等强电磁脉冲易造成电子设备功能失效甚至损毁,在实际工程实施中用金属腔体对电子设备进行屏蔽是常用的强电磁脉冲抑制手段。基于电磁仿真计算,对含矩形孔缝金属腔体的强电磁脉冲耦合特性进行了系统研究,阐述了孔缝宽长比、腔体尺寸等因素对多种不同类型强电磁脉冲(核电磁脉冲、宽带高功率微波、窄带高功率微波)作用下腔体内耦合场的影响;并以此为基础,重点分析了强电磁脉冲与含孔缝金属腔体之间的作用机制。研究结果表明:不同类型强电磁脉冲耦合信号差异明显,金属腔体对强电磁脉冲的响应是腔体谐振模式、孔缝谐振频率与强电磁脉冲共同作用的结果;当腔体谐振模式、孔缝谐振频率在强电磁脉冲的带内时,腔体内部的耦合场会出现增强效应;特别地,腔体与孔缝间的相互作用还可造成腔体与缝隙的谐振频率发生偏移。因此,在为电子设备设计金属屏蔽外壳时,应基于不同强电磁脉冲的频带范围,对腔体与孔缝的尺寸进行综合设计,抑制腔体、孔缝谐振及谐振频率偏移,提升其强电磁脉冲防护性能。High-intensity electromagnetic pulses like high-altitude electromagnetic pulse(HEMP),high power microwave(HPM)are very harmful to electronic devices,which will cause malfunction or even damage to electronics.Using metallic cavity to isolate electronic systems from high-intensity electromagnetic pulse is an important and effective way to lessen the effect.Herein,we performed a systematic study on coupling property of metallic cavity with a rectangular aperture under the excitation of three types of high-intensity electromagnetic pulses,i.e.,HEMP,wide-band HPM,and narrow-band HPM.The width/length ratio of aperture and cavity size were varied to investigate their effect on electromagnetic coupling.The interaction mechanism of high-intensity electromagnetic pulses and the metallic cavity was also carefully analyzed.The results demonstrate that the shielding property of metallic cavity is highly dependent on resonance mode of cavity,resonant frequency of aperture as well as the spectral characteristics of high-intensity electromagnetic pulse.When the resonance mode of cavity,and/or resonant frequency of aperture are within the bandwidth of high-intensity electromagnetic pulse,an enlarged coupling electromagnetic field in the metallic is always produced.Specifically,the interaction between the cavity and aperture can give rise to spectral shift of resonant frequency.Therefore,to obtain excellent shielding effect,we need to take into consideration the suppression of resonance mode of cavity,resonant frequency of apertureas well as the spectral shift when performing electromagnetic protection of electronic devices.

关 键 词：金属腔体 强电磁脉冲 屏蔽效能 电磁耦合 谐振模式 

分 类 号：O441.4[理学—电磁学]