A reliability-based AlGaN/GaN HEMT model considering high drain bias voltage RF ageing

Reliability knowledge of AlGaN/GaN High Electron Mobility Transistors (HEMT) remains a major challenge to provide safe power devices. In order to understand degradation mechanisms related to this technology, accurate life tests must be performed. In this paper, saturated-pulsed-RF stress tests at enhanced drain bias voltage are performed on an AlGaN/GaN HEMT based power amplifier. These tests have permitted to highlight the device's parameters responsible for the performance drop. Finally, they have been included in a large signal HEMT model to predict the power amplifier behavior under enhanced drain bias voltage operation. Results on a 45V drain bias voltage ageing test and the way to integrate them in a large signal model are discussed. Then, measured and simulated amplifier performances are compared.