基于波形重建的开缝小腔体电磁脉冲屏蔽效能仿真分析

Simulation and Analysis of EMP Shielding Effectiveness of Slotted Small Cavity with Waveform Reconstruction Method

随着高功率电磁脉冲源的大量应用,电子设备的电磁脉冲防护成为电磁兼容领域的重要研究内容。为评估屏蔽体的电磁脉冲屏蔽效能,在分析波形重建方法的基础上,提出了开缝腔体屏蔽效能的最小相位法传递函数重构及波形恢复流程图,通过仿真计算和实验获得小腔体的频域屏蔽效能及其传递函数,对腔体内的方波电磁脉冲进行重建,分析了开缝小腔体对方波电磁脉冲的屏蔽效果。利用实测数据进行仿真计算结果表明:基于最小相位法的波形重建方法能够计算出电磁脉冲透过孔缝后的时域波形,计算得到的2种开缝屏蔽体的峰值屏蔽效能与屏蔽效能频域实测谱的低频屏蔽效能一致;利用该方法还能进行任意波形脉冲激励下的屏蔽体屏蔽效能计算,具有计算简单、预测效果好的优点。

With the application of high power electromagnetic pulse sources, it is important that electromagnetic pulse protection of electronic devices is researched in the domain of electromagnetic compatibility. To evaluate the electromag- netic shielding effectiveness, we proposed a flow chart of transfer function reconstruction and waveform recovery with minimum phase method of the slotted cavity shielding effectiveness by analyzing waveform reconstruction. The shielding effectiveness and transfer function in frequency domain of a small cavity can be obtained through simulation and experi- ment. The square waveform of electromagnetic pulse in the cavity can be reconstructed to analyze the shielding effect to the square pulse waves. Experimental data and reconstruction results show that： the time domain waveform of electro- magnetic pulse through the slotted small cavity can be roughly calculated by the waveform reconstruction method based on minimum phase, and calculated shielding effectiveness results are consistent with the low-frequency shielding effec- tiveness measured in frequency domain; the method is suitable for estimation the time domain shielding effectiveness of slotted small cavity with arbitrary waveform electromagnetic pulse excitation, it has some advantages of simple calcula- tion and good prediction effect.