用FDTD法分析开孔金属板的屏蔽效能

FDTD Analysis for Shielding Effect of Metal Plate with Apertures

电子电气设备上的通风孔通常会成为机箱内部电磁能量耦合到外部去的通道,这些耦合出去的能量会成为电磁干扰,所以需要研究开孔金属板的屏蔽效能(SE).本文采用的是数值建模和实验结果进行比较的方法,时域有限差分法(FDTD)是一种优良的数值电磁场计算方法.本文应用它作为核心算法,对系列实验建立了仿真模型.仿真模型的运算结果和实验数据进行了比较,两者吻合得很好,证明了本文建模的成功.对比较结果的分析,进一步揭示了金属板上开孔的大小、形状、数目以及金属板厚度等各因素对屏蔽效能的影响,一些经验性的推论可供实际设计参考.

Aperture arrays for airflow in enclosure can become the coupling path of electromagnetic interference (EMI) from interior to external environment. Finite_Difference Time_Domain (FDTD) is a versatile computation technique for simulation of electromagnetic radiation in EMC analysis. Herein the FDTD is applied to investigate the shielding effect (SE) of a metal plate with aperture arrays. The factors such as the size and shape of aperture, sum of apertures, the thickness of the metal plate are studied herein to see how they act on the SE. The numerical results agree well with the measurements. And some empirical conclusion will benefit the practical design.