具有屏蔽机壳的电子设备系统级电磁敏感性分析方法

Analytical Method of Electromagnetic Susceptibility for Electronic Devices with Shielded Enclosure at System Level

提出了一种基于场路结合、对具有屏蔽机壳的电子设备进行系统级电磁敏感性(EMS)仿真分析的新方法.该方法采用有限元法计算外部电场分布,对电场沿固定路径积分,得到所需的表面干扰电压,将外部电磁干扰对内部电路的影响等效为电压源的作用,再利用基于电路模型和全波分析相结合的方法对内部高速电路进行EMS仿真分析,弥补了以往在EMS分析时只以实验为主,缺乏理论依据的缺陷.实例仿真分析表明,该方法简单、直观,不仅可以详细分析电子设备内部高速电路中干扰的传播情况,而且可以对内部高速电路进行优化设计,提高了系统的抗干扰性.

Based on the combination of electromagnetic theory and circuit analysis, a new approach to the simulation analysis of electromagnetic susceptibility （EMS） for electronic devices with shielded enclosure at system level is presented, in which the finite element method is adopted to calculate the external electric field, the required surface interference voltage is obtained through integration of electric field along the appointed route, and the influence exerted by external electromagnetic interference on the internal circuit is regarded as an equivalent effect of the voltage source. Then, a method combining the full wave electromagnetic analysis with circuitbased model is used to carry out the EMS simulation analysis of internal high-speed circuit. This approach is superior to the previous EMS analysis which mainly relies on experiments but lack of theoretical basis. Simulation experiments show that the proposed method is easy and intuitional, and not only can be used to analyze detailedly the interference propagation in the internal highspeed circuit of electronic devices, but also to optimize the design of internal high-speed circuit to increase the interference immunity.