基于电流驱动模式的PCB共模干扰预测分析

Prediction and Analysis of PCB Common-Mode Radiation Based on Current-Driven Mode

共模辐射干扰普遍存在于电子产品中,是造成电子产品工作失灵和辐射发射测试超标的主要原因。通过高斯定理和安培环路定理求解麦克斯韦方程组,得到PCB地平面电感的数学表达式。通过对共模辐射的模式化分析,得到电流驱动模式共模辐射的数学表达式。用近似计算简化数学推导过程得到的表达式相对简单。本结果适用于小型EMC仿真软件,也可用于计算PCB地平面电感和共模辐射的电磁兼容专家系统。

Common-mode radiation commonly exists in electronic product. It is the main reason for the failure work and fall of radiation test of electronic products. Through the use of the Gauss theorem and the Ampere loop theorem to solute the Maxwell＇s equations, the mathematical expression of the PCB ground plane inductance is obtained, and then through the analyze of the current-driven mode radiation, the common-mode voltage expression of current-driven mode is got. The mathematical derivation process is simplified by partial approximate substitutions. The result of this paper can be used in simple EMC simulation software or PCB EMI expert system to calculate the PCB ground plane inductance and common-mode radiation.