FDTD modeling of heatsink RF characteristics for EMC mitigation

Due to their size and complex geometry, large heatsinks such as those used in the power electronics industry may enhance the radiated emissions produced by the circuits employing them. Such enhancement of the radio frequency (rf) radiation could cause the equipment to malfunction or to contravene current EMC regulations. In this paper, the electromagnetic resonant effects of heatsinks are examined using the finite-difference time-domain (FDTD) method and recommendations are made concerning the optimum geometry of heatsinks and the placement of components so as to mitigate potential EMC effects.