A common-emitter equivalent circuit model which represents both the self-heating and the current collapse as feedback from the collector current to the base-emitter voltage is developed for multi-finger InGaAs/GaAs HBTs. The modified Ebers-Moll model is verified by comparing the simulated and measured results. Good agreement is also achieved for the scattering parameters and I-V characteristics confirming the validity of the model for high frequency applications. (C) 2003 Elsevier Ltd. All rights reserved.