共差模分离的新思路

New Ideas Common Mode and Differential Mode Separation

长时间以来,许多学者认为,只要对LISN的L、N两路输出信号进行加或减法处理,就可以分离出共模或差模信号。但为什么至今无法在工程中获得广泛应用,重要的原因之一,也许是共差模隔离度在高频端的性能不够理想。本文提出另一种思路,用分别抑制共模、差模信号的思路来分离出共模和差模信号。10k Hz^30MHz频段的共差模隔离度大于40d B,满足实际使用要求,给EMI滤波器共差电路设计提供了可靠的依据。

For a long time, many scholars believe that as long as the LISN the L, N two output signals plus or minus treatment, It can be common mode and differential mode signal separated. But why has not get widely used in engineering. One important reason, perhaps poor performance occurs at high frequency common mode and differential mode isolation. This paper proposes an alternative idea, with respectively suppress common mode and differential- mode signal to separate the idea of common mode and differential mode signals. 10kHz - 30MHz frequency common mode differential mode isolation greater than 40dB, to meet the actual requirements. EMI filters for common mode and differential mode circuit design provides reliable basis.