针对电磁干扰(EMI)信号中的共模(CM)频谱和差模(DM)频谱分离技术难点,提出一种基于传输线变压器及补偿电容的噪声分离器。该分离网络利用传输线变压器良好的高频特性.并结合补偿电容的阻抗匹配设计,从而实现了CM和DM噪声的精确分离。对分离器的电路结构及其参数设计进行了深入的探讨,并设计完成了实验样机。通过DC/DC全桥变换器,实验验证了所提出的噪声分离器在CM和DM噪声分离方面的可行性和有效性。
Noise separators are wildly used in separating the common mode (CM) and differential mode (DM) signals in conducted electro magnetic interference(EMI) measurements.The high frequency performance of a single phase noise separator is improved.It is realized by a detailed calculation of the impedance characterization of the transmission line transformer.Then an impedance matching capacitance is added at the output terminal of the transmission line trans- former.The presented simulation results and laboratory tests validate the effectiveness of the proposed method.