Characterization of GaN Recovery Effects under High-Power Pulsed RF Stress

This paper discusses the characterization of GaN transistors or MMICs under pulsed high-power stress and their recovery behaviour. A fully calibrated measurement setup is introduced where both forward and reflected waves are measured at input and output. In particular, also the effect of trapping due to the RF pulse on for example the insertion phase or input impedance can be measured. Measurement examples are shown on transistors from two different GaN technologies and compared to measurements on a GaAs transistor. Recovery measurements on GaN transistors in series and shunt configuration have been performed, showing in-depth the effects relevant for application of these devices in array environments.