A study of DC and RF transconductance for different technologies of HEMT at low and high temperatures

We report on the measured effects of temperature on the DC and RF transconductance for several important HEMT technologies. Six different HEMT transistors were evaluated. Single- and double-heterojunction HEMTs, GaAs and GaN materials, virgin and multi-layer pHEMTs, and matched and pseudomorphic HEMTs are analyzed to enable a comparative and quantitative analysis for various transistor types. The temperature effects on the HEMT behavior vary remarkably with the considered transistor technology and working conditions. As a matter of fact, by changing the transistor and bias point, a higher temperature can yield an increase or decrease in the transconductance. It is worth noting that GaAs transistors have a bias point where the DC and RF transconductances are nearly invariant with temperature, owing to two opposing temperature effects canceling each other out, while no such bias condition was found for the GaN-based transistors.

Automated summary

This paper reports on the effects of temperature on the DC and RF transconductance for different HEMT technologies. Various transistor types including single- and double-heterojunction HEMTs, GaAs and GaN materials, virgin and multi-layer pHEMTs, and matched and pseudomorphic HEMTs were analyzed. The temperature effects on the HEMT behavior varied significantly depending on the transistor technology and working conditions. It was observed that the transconductance could either increase or decrease with higher temperature depending on the transistor and bias point. It is worth noting that GaAs transistors demonstrated temperature invariance at a certain bias point, while no such condition was found for GaN-based transistors.