Impact of RF stress on dispersion and power characteristics of AlGaN/GaN HEMTs

The impact of RF stress on dispersion and power characteristics of AlGaN/GaN HEMTs are reported. Reduced drain current ( /spl sim/ 67 mA/mm in the saturation region) and similar output power and power-added efficiency were found after RF stress. Transconductance dispersion is small before and after RF stress while output resistance dispersion reduces after RF stress. Tests performed under UV light suggest that the observed results may be attributed to trapping in the AlGaN/GaN HEMT layers.