A W-band cascaded double-stage distributed low-noise amplifier using feedback transmission line

We propose a W-band low-noise Amplifier (LNA) with flat moderated gain, low noise figure and high stability by using feedback effects in cascaded double-stage distributed amplifiers. 0.1 μm gate length InGaAl/InAlAs/GaAs metamorphic HEMTs with two fingers of a 30-μm gate width are used for a W-band LNA model in the design and simulation. A three-stage cascaded distributed amplifier utilizing feedback transmission line is described as well. The amplifier shows a small signal gain of 13 ± 0.9 dB and noise figure lower than 4.5 dB in a frequency range of 78-102 GHz, an input return loss (S₁₁) of -21 dB and an output return loss (S₂₂) of -16 dB at 94 GHz.