High-frequency modelling of EMI filters considering parasitic mutual couplings

Modeling of differential mode EMI filter is presented in this paper. 3D electromagnetic field modeling software CST MWS is used as a simulation tool. EMI filter consisting of two capacitors and two inductors is modeled considering parasitic mutual couplings between EMI filter components. Modeling is performed for different positions of capacitors and inductors on both single-sided and double-sided PCBs. Modeling results are compared to measurement results to verify CST MWS modeling precision and capabilities.