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.