表面金属化织物电磁屏蔽效能的数值计算

摘要

In this paper,two kinds of models are proposed to calculate the electromagnetic shielding effectiveness of the fabric after chemical plating based on the microstructure of the fabric.Firstly,a metal mesh model with different-shape micro holes is constructed by using the cutoff waveguide theory,and the effect of the shape and size of the micro holes on the electromagnetic shielding effectiveness is studied.The results indicates that with the increase of the diame-ter of micro hole,the electromagnetic shielding effectiveness decreased.When the diameter of hole is less than the depth of a hole,the electromagnetic shielding effectiveness values decreased quickly with the increase of the diameter of micro hole.For a square hole,a circular hole and a hexagonal hole,which has the same area,the shielding of the circular hole has the best performance when the pore is small,and the square hole has the best electromagnetic shielding effec-tiveness when the pores is large.Secondly,the calculation formula of the electromagnetic shielding effective-ness of the fabric with different-size micro holes is proposed by using the waveguide aperture coupling theory, and the electromagnetic shielding effectiveness of the metal plates with 20 different-size micro holes are calculat-ed.This method is expected to be further improved and expanded to make it more accurate to calculate the elec-tromagnetic shielding effectiveness of surface metallization fabric.%依据织物真实的微观结构，构建了两种模型来计算化学镀后织物的电磁屏蔽效能。利用截止波导理论法构建了具有不同形状微孔的金属网模型，研究微孔形状和大小对电磁屏蔽效能的影响。计算结果表明：随着微孔的增大，电磁屏蔽效能值减小；当微孔尺寸小于孔洞深度时，电磁屏蔽效能值随微孔减小而增大得更快；对于孔洞面积相同的正方形孔、圆形孔和六边形孔，当微孔较小时，圆形孔的屏蔽效能最好，而当微孔较大时，正方形孔的屏蔽效能最好。利用波导小孔耦合理论推导了微孔随机分布时织物电磁屏蔽效能的计算公式，并计算了随机分布20个大小不同孔洞金属板的电磁屏蔽效能。这种方法有望得到进一步完善和拓展，使之能够更加精确地计算表面金属化织物的电磁屏蔽效能。