Evaluation of Thermal Impedance by 3omega Method for Power Amplifier Behavioral Modeling

This paper addresses the study of the thermal impedance of commercial GaN transistors when the process design kit (PDK) does not provide accurate or complete information. Two Cree transistors have been characterized through simulation and experimental measurements using the so-called “3ω method”. One major advantage of the 3ω method is to allow identification of the thermal effects in conditions where traps are not excited. In this work, we bring some improvement to the original method in order to achieve better accuracy control. The ultimate aim is to assess the thermal impedance of a power amplifier from its design phase and to give adequate information to electrothermal behavioral models for the system level.