Wideband medium power amplifiers using a short gate-length GaAs MMIC process

We present the design of several wideband, millimeter-wave, MMIC, medium power amplifiers using a newly developed high-power, high-yield, 70 nm gate-length GaAs MMIC pHEMT process. These amplifiers cover a range of about 65-125 GHz, and were designed for the purpose of driving sub-millimeter wave multipliers in the local oscillator subsystem of the Atacama Large Millimeter Array (ALMA) radio telescope. The highest-frequency amplifiers in this chipset have average output power density over wide bandwidth of 200 mW/mm, representing the best performance to date for GaAs pHEMTs above W-Band.