A self aligned InGaP/GaAs power HBTs for L band power amplifier with low bias voltage are described.Base emitter metal self aligning,air bridge,and wafer thinning are used to improve microwave power performance.A power HBT with double size of emitter of (3μm×15μm)×12 is fabricated.When the packaged HBT operates in class AB at a collector bias of 3V,a maximum 23dBm output power with 45% power added efficiency is achieved at 2GHz.The results show that the InGaP/GaAs power HBTs have great potential in mobile communication systems operating at low bias voltage.
