Numerical modeling for heatsink emissions in power electronics

Abstract. The parasitic coupling between power semiconductors and the heat sink is responsible for noise current in Switching Mode Power Supply (SMPS) systems. In this paper, the variations in the radiation characteristics of heatsinks are investigated with respect to their geometries by use of numerical models. Analyses are facilitated by using a mopole antenna as an EMI receiver and by using simplified heatsink models as EMI transmitters to model the heatsink radiated emissions. In addition, the analysis is confirmed using laboratory measurements.