Fully integrated 3 x 3 mm BiFET stage-bypass power amplifier for WCDMA handset application

By using a merged process of a heterojunction bipolar transistor and a field effect transistor (BiFET), a stage-bypass power amplifier (PA) for wideband code division multiple access (WCDMA) application has been developed. The size of the PA was reduced by integrating control logic circuits on a single BiFET monolithic microwave integrated circuit with virtually identical performance compared to a previous work. Adopting the stage-bypass technique, this work accomplished remarkable average current reduction compared to a typical class-AB PA, thus contributing to extended operation time.