Third Order Notch over Multi-bias and Temperature in GaN and GaAs HEMTs

A detailed study about the shifting of third-order notch and threshold voltage with temperature for GaN and GaAs FETs were analyzed. For this purpose, a great deal of data over temperature between - 40 to 150°C were measured by using two-tone intermodulation distortion set up. It was found that the third order notch current point exactly follows the trends of threshold voltage (VT) shifting with temperature. The thermal response of V
T
demonstrates a raising trend in GaN and a falling trend in GaAs FETs. An analytical model for notch current was developed and well validated with the measured data. This study represents some significant and thorough understanding to investigate the device behaviour.