频率选择表面结构的电子系统K/Ka波段电磁屏蔽分析

Electromagnetic shielding analysis of electronic systems containing frequency selective surface structure in K/Ka band

电子设备和无线技术不断向K/Ka波段发展以及电子系统集成度的不断提高给电子系统的电磁屏蔽设计带来了严峻挑战。提出一种将频率选择表面(FSS)用于电子系统屏蔽的新方法,可以替代传统散热孔阵,在满足通风散热性能的同时确保电子系统在5G毫米波段的电磁屏蔽性能。基于金属腔中心点屏蔽效能和全局屏蔽效能,分析了FSS孔阵排布方式、电磁波极化与入射角度对金属外壳电磁屏蔽效能(SE)的影响。结果表明:FSS孔阵排布方式对金属腔屏蔽性能的影响较小,并且SE不受入射电磁波极化方式影响;含FSS通风孔阵的金属外壳在23.0~25.5 GHz范围内屏蔽效能约为30 dB,比含传统散热孔阵金属腔屏蔽效能提高15 dB。

The frequency continuous extension to K/Ka band for electronic devices and wireless technology,as well the fast development of integrated electronic system have made the electromagnetic shielding design of electronic systems increasingly challenging.In this paper,a new shielding method which incorporates frequency selective surface(FSS)into electronic systems to replace the conventional heat dissipation holes array is proposed.The proposed shielding method can meet the requirements of both ventilation and electromagnetic shielding performance at 5G millimeter wave band.Based on the shielding effectiveness(SE)at the center point in the enclosure and the global shielding effectiveness,the influences of the arrangement of FSS cells and the polarization and incident angle of electromagnetic waves on SEs of the metallic enclosure are analyzed.The results show that the arrangement of FSS cells have little effects on the shielding performance of the metallic enclosure,and SE hardly changes with the polarization of the electromagnetic waves.The shielding effectiveness of the metallic enclosure with the FSS is about 30 dB in the frequency range of 23.0−25.5 GHz,which is 15 dB higher than that of the enclosure with the conventional heat dissipation holes array.This demonstrates that the method proposed in this paper has better electromagnetic shielding while keep good ventilation at the same time.