BLT方程在箱体屏蔽效能分析中的应用

根据Robinson算法和电磁拓扑理论,提出了一种基于BLT方程的有孔箱体屏蔽效能分析方法,介绍了BLT方程的基本原理,推导出了描述孔缝耦合的BLT方程,建立了屏蔽箱体、孔逢、入射波等参数与屏蔽效能的函数关系,并扩展到偏心孔以及任意极化角的情形,分析了孔缝形状、尺寸以及观测点位置等对屏蔽效能的影响。在0~1GHz范围,对中心开孔箱体的屏蔽效能进行仿真,并与CST仿真结果进行对比,验证了方法效性,数值计算结果表明:文中算法不仅能够准确的描述出箱体屏蔽效能随入射波频率的变化关系,而且能有效地估算出屏蔽箱体的谐振频率。

The Application of BLT Equation to Analyzing Shielding Effectiveness of Enclosure with Aperture

According to Equivalent Circuit Model and Electromagnetic Topology Theory, a method of evaluating the shielding effectiveness(SE) based on BLT equation is proposed, and the basic principle of BLT equation is introduced, the BLT equation of cavity-seam coupling described is derived,the function relationship between SE and related parameters such as enclosure dimensions, aperture dimensions is not only built up, but also can be used in an extension situation including off-centre aperture and arbitrary polarization direction. The effect of the aperture shape, aperture area, and the test point on SE are also analyzed. The SE of single aperture is simulated within a frequency domain from 0 GHz to 1 GHz, compared with the CST results. The results indicate that the relationship between SE and the frequency of incident wave can not only be described accurately by this method, but also can the resonant frequency of the shielding enclosure be estimated effectively.