A hybrid EMI filter with ultra-wide bandwidth

This paper describes an integrated active and passive planar electromagnetic-interference (EMI) filter structure with effective noise suppression over a very wide bandwidth. Such hybrid EMI filter paves the way input filter design for future mega-hertz switching power converters. This study shows that it has superior performance over traditional active niters and passive niters. Spectral results of a switching converter from 150 kHz to 30 MHz using various of active, passive and the proposed hybrid EMI filters have confirmed the validity and high performance of the hybrid EMI filter.