A Ku/K/Ka-Band GaAs MMIC Load-Modulated Amplifier with a Negative Group Delay Output Network

We present the design and characterization of a 50% bandwidth Ku/K/Ka-band 16–28 GHz load-modulated two-stage single-polarity bias MMIC power amplifier fabricated in a 0.15µm E-pHEMT GaAs process. Extended bandwidth is obtained with wideband matching networks and a negative group delay modified Doherty impedance inverter in the output combining network. Measured results show 12–15 dB gain, 24–27 dBm output power, 41/32% peak PAE, and 28/22% PAE average at P1dB/6dB output power back-off (OBO).