Ultra wideband cascade low noise amplifier implemented in 100-nm GaAs metamorphic-HEMTS technology

We present a state-of-the-art broadband (60 to 90 GHz, 40%) 4-stage low noise amplifier (LNA) in a GaAs metamorphic high electron mobility transistor (mHEMT) technology. The LNA, spanning several waveguide bands, is dedicated to radiometry, communication and instrumentation applications. It consumes 56 mW and exhibits a gain of more than 19 dB with flat frequency response and average noise figure of 2.5 dB. The design makes use of reactive feedback by source degeneration. Broadband matching was achieved by using enhanced L-C matching networks. Gate width was optimized for best noise figure and gain performance