A Fully Integrated 3.5 GHz Single Chip GaN Doherty PA for sub-6 GHz 5G

This paper describes the development of a fully-integrated packaged Doherty amplifier monolithic microwave integrated circuit (MMIC), fabricated on a 0.4 μm 28 V GaN-on-SiC process. It provides 18 dB of small-signal gain between 3.4 GHz and 3.8 GHz and delivers 45dBm of output power at saturation with a power-added efficiency (PAE) of 50 %, while maintaining a PAE of 31.5 % at 8 dB back-off. The PA is suited to many high-power applications for transmission of modulated signals including in a 5G base station transmitter. The PA may be used in conjunction with digital predistortion (DPD) for improved linearity.