High temperature operation of AlGaN/GaN HEMT

We investigated high temperature operation of AlGaN/GaN HEMTs. At channel temperature of 269 degC, a linear gain of 12.3 dB and a power added efficiency of 53.6% were achieved at 2.14 GHz, less than 50 V operations. These are sufficient performance to practical application. At channel temperature of 368 degC, the linear gain was 10.4 dB and a power added efficiency of 43.9% was achieved. We also investigated the temperature dependence of equivalent circuit values, and found that the temperature dependence of saturated output power and the linear gain is originated from the temperature dependence of electron velocity in the channel.