Broadband GaAs MESFET and GaN HEMT resistive feedback power amplifiers

We report 0.2 to 6-GHz MMIC power amplifiers with 12-dB gain, over 23-dBm output power, and more than 25% power-added efficiency (PAE) in a GaAs MESFET technology offering 18 GHz f/sub /spl tau// and 12-V breakdown. These circuits have gain-bandwidth products of /spl sim/1.3/spl middot/f/sub /spl tau// and are more efficient than distributed power amplifiers. A first demonstration of similar circuits in GaN/AlGaN HEMT technology yielded 11-dB gain, 0.2 to 7.5-GHz bandwidth amplifiers with over 31.5-dBm output power and up to 15% PAE. With improved devices and models we expect significantly higher power from the GaN HEMT circuits.