电大开孔箱体屏蔽效能分析解析模型

Formulation for shielding effectiveness analysis of a rectangular enclosure with an electrically large aperture

电磁脉冲武器能够通过"前、后门"耦合效应对箱体内部电子元器件及电路板造成损伤,从而对电气电子设备的安全性构成严重威胁,因此,开展箱体电磁屏蔽效能的分析研究具有重要意义.推导了任意入射波条件下电大开孔箱体屏蔽系数的解析解,并在此基础上对箱体屏蔽效能进行了分析研究.首先通过矢量分解,得出任意入射平面波的坐标分量;再基于Cohn模型,获得了电大开孔的等效电偶、磁偶极子;然后通过镜像原理,计算出总的赫兹电矢量位、磁矢量位;最终求得电大开孔箱体内部任意观测点的电场解析解,用于箱体屏蔽系数计算.设计了5组验证性实验,仿真结果表明:该解析算法相对CST的均方误差为11.565 d B,绝对误差为8.015 d B,相关系数为0.921,从而验证了该算法的准确性;解析算法仿真的平均耗时为0.183 s,仅占CST耗时的1/7530,从而验证了该算法的高效性.

Since electric components and printed circuit board in the enclosure can be destroyed by electromagnetic pulse weapons through ＂front door and back door＂ coupling, which is a great threat to the operational security, the study of the shielding effectiveness is of important significance. A formulation for shielding effectiveness analysis of a rectangular enclosure with an electrically large aperture is proposed in this paper. Firstly, the plane wave with oblique incidence and polarization is decomposed. Secondly, based on the Cohn model, the equivalent electric and magnetic dipole of the electrically large aperture is computed. Thirdly, the total Hertz electric and magnetic vector potential is obtained through mirror procedure. Finally, the electric field inside an enclosure with electrically large aperture is formulated, which is used for shielding effectiveness calculation. Five verification experiments are designed. Simulation result shows that the mean square error and absolute error of this method compared to computer simulation technology（CST） microwave studio are 11.565 d B and 8.015 d B respectively, the correlation coefficient is 0.921, through which the accuracy of this method is verified. The simulation time of this method is 0.183 s, which is only 1/7530 times of CST, so its efficiency is obvious.