Derivation of insertion loss equations for EMI filter design

Abstract

In this paper, the derivation of insertion loss equations for designing EMI filters used in power electronic applications e.g. switched-mode power supplies is proposed. Classical passive EMI filter topologies i.e. LC-, CL-, π-configurations are derived. With the provided insertion loss equations and the known magnitude and phase of the terminated noise source and load impedances, the EMI filter can be optimally and systematically designed.