Simplified Large Signal Models for Heterojunction Bipolar Transistors

Abstract

Large signal models for AlGaAs/GaAs and GalnP/GaAs Heterojunction Bipolar Transistor devices have been generated using two different techniques which allows the generation of simple models for CAD application. The first technique uses the standard SPICE BJT Gummel-Poon model, where the model is suitably modified to take into account self-heating, gain compression and parasitic effects. The other technique is based on traditional large signal modelling technique for MESFET devices, using an extension of multi-bias small hybrid-Pl model. Once again the device effects have been suitably accounted for. Performance of both types of model is presented in the form of measured and modelled S-parameters and DC and Harmonic characteristics.