Measurement of junction temperature in heterojunction bipolar transistors

Abstract

A technique to calculate junction temperature of heterojunction bipolar transistors is presented. By measurement of collector current as a function of V/sub BE/ at only a few substrate temperatures, the junction temperature at different biases can be derived. Results are shown from a multi-finger AlGaAs/GaAs transistor and a single-finger InGaP/GaAs transistor.