Suppression of Electromagnetic Interference using Multi-Stage Integrated Filtering with Screening and Partitioning

In this paper, we introduce the use of integrated filtering techniques to suppress EM (Electromagnetic) interference generated by a switching cell. Combinations of screening and shielding techniques are applied to multi-stage filters and evaluated over a frequency range from 100kHz to 1GHz in order to assess their ability to suppress both conducted and radiated noise emission from switching cells. Proper filter selection, the partitioning and screening of filter stages and the ordering of the filter stages are shown to be key to achieving over 120dB attenuation.