Analysis and simulation of the basic structures of active EMI filters

The main goals of this paper are an analysis and a simulation of selected basic structures of active EMI filters. The first part contains a presentation of selected structures of active filters, along with categorization by their properties in the field of detection and compensation of EMI noise and by the kind of feedback. Each structure's description is accompanied by an analytical discussion of their properties such as insertion loss (IL) and the impedance increase (ΔZ>sub>n). The second part contains results of simulations of the presented structures, with the aim being a comparison of their characteristics and determining proper operation conditions.