Fully Integrated 39 dBm, 3-Stage Doherty PA MMIC in a Low-Voltage GaAs HBT Technology

A power amplifier, designed and fabricated in a low voltage GaAs hetero-junction bipolar transistor technology with a Doherty output stage, is presented. A pre-driver, a driver, main and peaking amplifiers, bias circuits, a 90^° power splitter, and the Doherty impedance transformer are integrated on a single chip. Measured key performance parameters include a P1dB compression point of at least 38.8 dBm over the US digital dividend band ranging from 728 to 768 MHz, and a PAE of 37% for a 5 MHz long term evolution downlink signal with 7.16 dB peak-to-average ratio.