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

Abstract

This work describes an approach for small signal modelling of GaAs‐based heterojunction bipolar transistors (HBTs) for low‐voltage/high‐power application (i.e., Vce=3 V, Jc=3×104 A/cm2). 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 Π‐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°C. ©2000 John Wiley & Sons, Inc. Int J RF and Microwave CAE 10: 33–42, 2000.