Maximum Radiated Emissions Evaluation for the Heatsink/IC Structure Using the Measured Near Electrical Field

Creating an equivalent field source is an efficient method for predicting radiated emissions from IC structures. In this paper, the maximum radiated emissions for a heat-sink/IC structure is predicted by creating an equivalent source from the measured electrical field (E-field) in the gap between the heatsink and IC. The E-field is detected by an E-field probe made of an open coaxial cable coated with absorbing material. A numerical model is built in the computer simulation technology microwave studio to obtain the maximum radiated field, where the measured E-field is used as a source to excite the heat-sink model. The evaluated maximum radiated field is in good agreement with the measured value; the error is within 7 dB up to 40 GHz for the source with phase, and 7 dB up to 10 GHz for the phaseless measurement.