High-performance Ka-band monolithic low-noise amplifiers using 0.2-μm dry-recessed GaAs PHEMTs

Ka-band ultra-low-noise amplifiers fabricated with a manufacturable dry-recess process are presented. Low-damage selective dry etching was used for gate recess to achieve uniform threshold voltage (Vth) and saturation current (I/sub dss/). Threefold improvement in Vth uniformity was achieved in comparison with the wet recess process. Fabricated PHEMT low-noise amplifiers (LNAs) employing 0.2-μm mushroom gates showed an average noise figure of 2.2 dB from 31-36 GHz with an associated gain of 22.5 dB. At the design frequency of 35 GHz, the noise figure was less than 2 dB. This is among the best results ever reported for Ka-band LNA's.