Estimation of deviation of conducted emission measurement without LISN

Common mode (CM) and differential mode (DM) conducted emissions without the line impedance stabilization network (LISN) is investigated from the perspective of CM and DM impedances. Using a switched-mode power supply (SMPS) as an equipment under test (EUT), the in-circuit CM and DM impedances of the actual measurement setup with and without LISN are extracted so that the deviation of conducted emission measurement without LISN from that of with LISN can be revealed and demonstrated.