摘要
微弱信号检测设备因其检测对象的幅值比较小且易受电磁噪声干扰,所以如何有效地抑制外部电磁干扰非常重要。以微弱信号检测电路的屏蔽腔体为研究对象,采用有限元法对具有孔缝结构的矩形腔体进行建模仿真,分析孔缝的尺寸、形状对屏蔽效能的影响。仿真结果表明:采用多排圆形小孔代替相同面积的矩形缝隙后,屏蔽效能在0.1 GHz^0.8 GHz范围内提高了20 dB以上,在0.8 GHz^1 GHz范围内提高了35 dB。同时得到屏蔽腔体的谐振频率以及腔体内部不同位置处的屏蔽效能。仿真结果有利于电路和器件的合理布局,进而提高微弱信号检测设备的抗电磁干扰能力。
The objects＇ amplitude of weak signal detectors is very small and susceptible to EMI,so how to suppress the external EMI effectively is very important. In order to analyze how the size and shape of aperture can influence the shielding effectiveness,this paper studies a weak signal detector＇s rectangular cavity and models of the shielding body with apertures using FEM. The simulation results show that rows of small round holes instead of the same area of rectangular slot can improve the shielding effectiveness more than 20 dB in 0. 1 GHz ~ 0. 8 GHz,and 35 dB in0. 8 GHz ~ 1 GHz. Besides,the resonant frequency of the shielding cavity and shielding effectiveness of different position inside the cavity can be gained. The conclusion is helpful for the reasonable layout of the circuit and device,thus it can improve the ability of weak signal detectors to suppress the EMI.
出处
《电子器件》
CAS
北大核心
2013年第5期635-638,共4页
Chinese Journal of Electron Devices
关键词
微弱信号检测
有限元法
屏蔽效能
孔缝
weak signal detection
finite element method
shielding effectiveness
apertures
