A fully integrated Ku-band Doherty amplifier MMIC

The design and performance of a fully integrated Ku-band Doherty amplifier monolithic microwave integrated circuit (MMIC) is presented. The circuit is implemented in 0.25-μm pHEMT MMIC technology and demonstrates the feasibility of the Doherty approach at Ku-band frequencies. The fabricated devices achieved a two-tone power-added efficiency of 40% with a corresponding third-order C/I ratio of 24 dBc at 17 GHz. To the author's knowledge this is the first fully integrated pHEMT Doherty amplifier MMIC as well as the first experimental results for a Doherty amplifier at Ku-band reported to date.