W-band monolithic low noise amplifiers for advanced microwave scanning radiometer

Monolithic low noise amplifiers using 0.15-μm AlGaAs-InGaAs-GaAs pseudomorphic HEMTs with a passivation film have been developed at W-band for the Advanced Microwave Scanning Radiometer. A two-stage monolithic amplifier has achieved a noise figure of 3.4 dB with a small signal gain of 8.7 dB at 91 GHz. A six-stage amplifier cascading three two-stage monolithic amplifier chips has achieved a noise figure of 4.2 dB with a small signal gain of 29.7 dB at 91 GHz. Taking into account the minimum noise figure of 2.5 dB with an associated gain of 4.3 dB of 0.15×60 μm
²
PHEMTs at 90 GHz, these results demonstrate that a good noise matching has been successfully achieved.