Nonlinear HBT models for HVHBT 15W power amplifiers

Nonlinear HBT models are presented for 15W power amplifiers with superior back-off linearity. Each amplifier consists of 8 Building Blocks of 28V InGaP/GaAs HBT. The P1dB is 42dBm. The models are based on the AHBT model for the Building Block (1BB) reported previously. The model for the amplifier at 2.14GHz is scaled from the AHBT model for 1BB whereas the model for the amplifier at 940MHz is a revised model due to modifications in the HBT layout designed for that frequency. Key device parameters are adjusted based on the changes in layout and the measured device characteristics to avoid a standard time consuming modeling process. Both models can precisely simulate all aspects of nonlinear performance of amplifiers such as output power, gain, P1dB, operation current, efficiency, IM3 and ACLR. Good match between simulation and measurement has been achieved. Models are used to improve RF and ruggedness performance in amplifier designs.