Collapse and large signal modelling of GaAs field effect transistors at 77 K

Abstract

A complete electrical characterization of different types of GaAs field effect transistors at liquid nitrogen temperature is performed. The trapping-detrapping mechanisms on deep levels are particularly adressed and a method is proposed to circumvent the collapse phenomenom which otherwise limits the electrical performances. From these measurements a HEMT non-linear model is extracted and is found efficient for the prediction of the large signal power out versus power in characteristic of a cooled HEMT. A further application could be the optimized design of a cooled low phase noise oscillator