Modeling, Analysis and Mitigation of Radiated EMI Due to PCB Ground Impedance in a 65 W High-Density Active-Clamp Flyback Converter

This article first reviewed the modeling and prediction techniques for the radiated electromagnetic interference (EMI) in active-clamp flyback (ACF) power converters. An improved radiated EMI model was then developed including the PCB ground impedance based on the ACF converter under investigation. Next, the improved radiated EMI model was quantified and experimentally verified. Two mitigation techniques were developed for the radiated EMI based on the improved model. Experiments were conducted to verify the developed analysis and mitigation techniques for the radiated EMI. The proposed modeling and mitigation techniques were finally extended to other isolated power converter topologies.