Abstract
An electro-thermal simulation for a microwave gallium nitride (GaN) field-effect transistor (FET) high-speed-switching power-supply was carried out to precisely estimate the influence of the self-heating effect on high-power operation. In this simulation, significant differences in the output power, power efficiency, and operation temperature of the FET were confirmed in comparison with calculated results for a simplified ideal model, when the switching frequency was changed from 10 MHz to several GHz, especially at the higher frequency range. For pulse-width modulation switching, the maximum variation of the operation temperature according to the output voltage variation was obtained at a center frequency of 2.5 MHz, which was about 44% of the relative temperature variation relative to the average temperature increase.
