Thermal Impedance Extraction From Electrical Measurements for Double‐Ended Gate Transistors

Transistor's thermal impedance is a parameter of prime importance to predict the device peak temperature in applications of power and RF electronics featuring time‐dependent dissipated power. In the context of the upcoming GaN HEMT technology, an innovative methodology is hereby detailed for the extraction of a transistor thermal dynamic behavior. This technique uses the dependence of the Gate resistance over temperature and thus only requires common electrical measurement of the device. An original technique is introduced to make this method robust to an inherent electrical coupling effect. An electrical method is introduced to extract a transistor's thermal impedance. The extraction is based on the dynamic measurement of the gate electrode resistance. Equations are detailed in time and frequency domains introducing a parasitic coupling terms. An innovative measurement technique to effectively filter out this parasitic term is developed and validated experimentally.