CMOS/BiCMOS power amplifier technology trend in Japan

Aiming for 2-5GHz band transceiver system on a chip, the integration of RF section has been developed by using conventional CMOS/BiCMOS (SiGeCMOS) process. The attempts to integrate power amplifiers (PA's) have been successful for low transmit power system such as Bluetooth, but these attempts are very limited due to the poor power handling capability of FET's in CMOS and the distortion characteristics of BJT's(HBT's) in BiCMOS. From the point of view of a circuit designer, this paper reviews the recent research activities of CMOS/BiCMOS PA's in Japan, and also describes the details of (1) the feasibility study of PA's using conventional CMOS process, and (2) the circuitry trials of distortion reduction for BJT(HBT) PA's.