Reconfigurable Millimeter-Wave Power Amplifiers in GaN and SOI Using Passive Load Modulation
5G applications in millimeter-wave bands have challenging requirements for power amplifiers (PAs) in handsets, picocells, and even basestations, and GaN in basestations. We propose passive outphasing load modulation (POLM) as a generalizable tuning approach that can be applied to various device technologies. Load modulation for high average efficiency as well as static tuning in the presence of load variation is described. The application of POLM to CMOS SOI and GaN PAs at 28 GHz is discussed and verified through measurements of different classes of operation and broadband waveforms.