AlGaN/GaN HEMT TRAP CHARACTERISTIC FREQUENCY DEPENDENCE ON TEMPERATURE AND ITS IMPACT ON THE RF POWER AMPLIFIER LINEARIZABILITY

Abstract

This paper presents a study of the linearizability of AlGaN/GaN HEMT based RF power amplifiers, RFPAs, and its relation with the active device trap activation energy. Based on the theory of thermally activated traps and on the experimental determination of the trap activation energy, we could show that despite different devices may exhibit traps with the same emission timeconstant at room temperature, their characteristic frequency may change significantly under nominal operation because of their temperature rise. And this was found to be key to explain the distinct linearizability performance of the tested devices because different stimulus dynamics excite the long-term memory effects imposed by traps with sensible different levels.