Characterization of the Impairment and Recovery of GaN-HEMTs in Low-Noise Amplifiers under Input Overdrive

This paper reports an investigation of the dynamic behavior of a GaN-HEMT, which is subjected to high reverse gate voltage pulses. These stress conditions are typical for robust LNAs under RF input overdrive and their quick recovery to the initial operating state is crucial but scarcely investigated. It was found that trapping effects similar to those in power amplifiers may play a major role in the impairment and recovery process of GaN HEMT-based LNAs with Fe-doping in the buffer. The interaction with traps and the resulting adverse effects on the device operation were found to be in the range of microseconds. Measurements at elevated temperatures suggest that the recovery time of the transistor is mainly governed by the emission of occupied traps, which takes place in the order of milliseconds. The characterization method is suited to predict the transient effects of LNAs under input overdrive.