Parameter extraction for HBT's temperature dependent large signal equivalent circuit model

An eleven node large signal HBT model in hybrid-pi configuration is investigated which is derived from HBT technology. This is the first circuit simulation model where the temperature is introduced as a variable simulation parameter using the concept of thermal resistance and pseudotemperature to account for the temperature dependent thermal conductivity of GaAs. The temperature and bias dependence of key model parameters - thermal resistance, transit time, emitter resistance, base-emitter and base-collector junction parameters - are extracted analytically from measured DC and S-parameter data in the temperature range from 20 deg C to 160 deg C using on-wafer thermochuk measurements. The devices have ft and fmax values of 40 GHz each. The verification of the proposed model is carried out on a simple oscillator circuit at 4.7 GHz, where the temperature dependence of oscillation frequency and ouput power of the first three harmonics is compared to measured data.