Broadband Outphasing Power Amplifier Using Doherty-Chireix Continuum in a GaN MMIC Process

This paper presents the first experimental investigation of a broadband outphasing power amplifier designed in a 150nm GaN process utilizing the Doherty-Chireix Continuum. Simulations show a peak drain efficiency above 35% from 3.5-7 GHz. Peak drain efficiency was measured to be 53% when using a pulsed-RF signal at 3.5 GHz with a pulse width of 1μs and duty rate of 0.1%. Series inductors and shunt capacitors were used to minimize the total die area. The broadband outphasing power amplifier has a total die area of 3mm x 4mm.