A C-band InGaP/GaAs HBT power transistor with an optimized material structure and device peripheral structure is designed and fabricated by base-emitter metal self-aligning,emitter ballasting,and an electric plated air bridge.The measured BVCBO is greater than 31V and the BVCEO is greater than 21V.At a frequency of 5.4GHz,the saturated CW output power of the fabricated HBT power transistor is more than 1.4W with a maximum power density of 3.5W/mm,and the power added efficiency is greater than 40%.
