A large signal model for a GaInP/GaAs HBT

Abstract

A large signal model for a GaInP/GaAs Heterojunction Bipolar Transistor is presented. The proposed model is a lumped element hybrid-pi topology. The extrinsic elements are determined using direct extraction techniques and the intrinsic elements are obtained from a combination of mainly direct small signal extraction and optimisation. The dc transfer characteristics are modelled using a V/sub ce/ dependent function where the constants of the equation are made to vary with base current I/sub b/. Allowances for the non uniform gain of the device are also included. The model gives good agreement between measured and modelled dc characteristics, s-parameters and power transfer characteristics. This model can be implemented on most up to date CAD packages, and has been generated over a range of devices.