A novel heatsink with mushroom-type EBG structure for EMI radiation suppression

High electromagnetic interference (EMI) radiation is becoming a critical problem as the operating frequency of the electronic devices increases rapidly. In this paper, the mushroom-type electromagnetic band gap (EBG) structure attached on the bottom of the heatsink is proposed to suppress high EMI radiation of packages within a specific frequency range. To confirm the effects of the novel heatsink with mushroom-type EBG structure, full-wave simulation and measurement in the semi-anechoic chamber (SAC) have been carried out to validate and quantify EMI radiation suppression. The proposed novel heatsink with mushroom-type EBG structure can keep EMI radiation at a low level, which offers the remarkable suppression by approximately 10 dB on average in the frequency range from 9.2 GHz to 15.8 GHz in simulation and by approximately 8 dB on average in the frequency range from 9.8 GHz to 15.6 GHz in measurement.