A 17.3-20.3 GHz Doherty Power Amplifier with 14W Saturated Output Power and 28% PAE at 6dB OPBO in 150nm GaN Technology

This paper describes the design and characterization of a 14W Ka-band three-stage GaN Doherty power amplifier. The MMIC, developed on 0.15μm gate length space evaluated GaN technology on SiC substrate, is the final stage of a downlink satellite transmitter in the 17.3-20.3 GHz frequency band. Large signal measurements exhibited saturated output power of 41.5dBm with power added efficiency of 32% and 28% at 3dB and 6dB of output power back-off, respectively. To the author's knowledge, this represents the highest output power in the frequency range for a Doherty amplifier while with minimum degradation of efficiency at 3 and 6 dB of OPBO.