Modelling of heterojunction bipolar transistors (HBTs) based on gallium arsenide (GaAs)

This work describes an approach for small signal modelling of GaAs-based heterojunction bipolar transistors (HBTs) for low-voltage/high-power application (i.e., V-ce = 3 V, J(c) =3 X 10(4) A/cm(2)). The parameter extraction procedure is discussed in detail. Furthermore, it is demonstrated that the model is fully scalable with respect to emitter area by comparison of simulated and measured S-parameters in the frequency range from DC to 20 GHz. Based on the small signal model, a nonlinear large signal model with the same II-type topology is proposed. It has a small number of parameters and considers self-heating, which is particularly important for HBTs. Parameter extraction is discussed and it is demonstrated by comparison of simulation and measurement that the model can accurately predict the DC characteristics of a HBT for ambient temperatures ranging from 20 to 100 degrees C. (C) 2000 John Wiley & Sons, Inc.