Measurement of Common-Mode and Differential-Mode Noise Source Impedances Using a Current Probe and Single Path LISNs

A measurement method of common-mode (CM) and differential-mode (DM) noise source impedances is presented and validated using a current probe and two single path LISNs. By this method, the noise source impedances and current amplitude of CM and DM conducted noises can be obtained simultaneously, without interrupting the normal operation of the equipment under test (EUT). The experiment results show that this method is quick and effective in noise source impedance measurement and suitable for electromagnetic conductive interference filter design.