A scalable high power nonlinear HBT model for a 28V HVHBT

A scalable nonlinear HBT model for a building block (1 BB) of 28 V InGaP/GaAs HBT is presented. It is based on the AgilentHBT (AHBT) model. The building block consists of 32 finger HBTs, an input pre-matching circuit and a transistor used as an emitter follower in the related bias circuit. The P1 dB of 1 BB is 32.5 dBm. The model can account not only for DC, thermal, junction capacitances, S-parameters but also RF power, gain, IM3, operation current and collector efficiency. A good match between simulation and measurement has been achieved. By using a multiplicity parameter the model can accurately predict the DC and nonlinear RF performance of two building blocks (64 fingers, P1 dB of 35.7 dBm) and four building blocks (128 fingers, P1dB of 38.2 dBm).