A Q-band amplifier with low noise figure and medium output power capability for ALMA band-1 receiver

This paper presents an amplifier for Q-band radio astronomy applications in 0.1-μm GaAs pseudomorphic high electron mobility transistor (pHEMT) process. The amplifier is designed such that it achieves wide bandwidth, flat gain, and low noise with good 1-dB output power compression level (OP_1db) aiming to be used in the receiver of the ALMA Band-1 telescope. Measurements on the amplifier verify its OP_1db is better than 7.6 dBm from 35 GHz to 50 GHz, achieving minimum noise figure (NF) of 3.2 dB at 41 GHz, with maximum power-added efficiency (PAE) of 17.9% at 35 GHz.