Abstract: A 28 GHz high power, high efficiency, millimeter wave power amplifier based on SiGe technology is proposed for the sixth generation of mobile communications system (6G) communication system. The high-performance heterojunction bipolar transistor is used to form a differential Cascode amplifier structure. The low impedance of the base of the common base transistor significantly improves the breakdown voltage, which can greatly increase the output voltage swing, so that the output power. Compared with the traditional LC matching network, transformer has less insertion loss and wider bandwidth. The simulation results show that the output 1 dB compression point is 18.6 dBm, the power added efficiency is 28.9%, and the power gain is 17.3 dB. By applying the proposed amplifier in a 6G communication downlink system simulation, the system can provide a high data rate of 1.34 Tbit/s with 89 antenna driven branch.

Key words: power amplifiers, transformer matching, the sixth generation of mobile communications system