Ka-Band MMIC Implementation of a Load-Modulating Loop Combiner Power Amplifier

This letter presents a MMIC implementation of the Load-Modulating Loop Combiner (LMLC) power amplifier (PA) architecture for Ka-band operation. This architecture incorporates elements of a feed-forward amplifier topology and the Doherty power amplifier to provide load modulation operation and improved linearity performance. A GaN MMIC operating at 28 GHz was designed and measured. The device presented in this work operates with a peak output power of 33.4 dBm and 33.7% peak PAE. Modulated measurements with a 100 MHz LTE signal are also presented.