脉冲激光发射模块电磁屏蔽效能仿真分析

目的 提高脉冲激光发射模块的电磁兼容性。方法 基于腔体的电磁屏蔽机理，使用HFSS软件，建立脉冲激光发射模块腔体模型，以电磁敏感度、电磁干扰2个方面对腔体电磁屏蔽效能进行仿真分析。结果 设计的双层屏蔽腔体在电磁波辐照频率为1~100 kHz时，屏蔽效能达到28 dB；电磁波辐照频率为0.2~18 GHz时，屏蔽效能达到47 dB。结论 当电磁波辐照频率在1~100 kHz时，腔体的屏蔽效能随频率的增加而增大。辐射源外部激励时，双层屏蔽腔体使用外层铁内层铜屏蔽效能较高。电磁波辐照频率在0.2～18 GHz时，腔体的屏蔽效能随频率的增大而减小，且发生了谐振效应。当腔体厚度相等时，双层屏蔽的屏蔽效能高于单层屏蔽。使用电缆连接器代替孔洞进行信号传输时，腔体屏蔽效能增加。

Simulation Analysis of Electromagnetic Shielding Effectiveness on Pulse Laser Transmitting Module

This paper aims to improve the electromagnetic compatibility of pulsed laser transmitting module. Based on the electromagnetic shielding mechanism of cavity, HFSS software was used to establish the cavity model of pulsed laser emission module, and the electromagnetic shielding effectiveness of cavity was simulated and analyzed in terms of electromagnetic sensitivity and electromagnetic interference. The shielding effectiveness of the double-layer shielding cavity can reach 28 dB when the electromagnetic radiation frequency is from 1 kHz to 100 kHz. When the electromagnetic wave irradiation frequency is 0.2-18GHz, the shielding effectiveness reaches 47 dB. When the radiation frequency of electromagnetic wave is between 1 kHz and 100 kHz, the shielding effectiveness of cavity increases with the increase of frequency. When the radiation source is excited externally, the shielding effectiveness of the double-layer shielding cavity is higher by using the outer layer of iron and the inner layer of copper. When the electromagnetic wave irradiation frequency is 0.2-18 GHz, the shielding effectiveness of the cavity decreases with the increase of the frequency, and the resonance effect occurs. When the cavity thickness is equal, the shielding effectiveness of double-layer shielding is higher than that of single layer shielding. When using cable connectors instead of holes for signal transmission, cavity shielding effectiveness increases.