Extended D-Band Low-Noise-Amplifier MMICs Based on a 50-nm Metamorphic HEMT Technology

In this paper, two low-noise-amplifier (LNA) monolithic microwave integrated circuits (MMICs) in a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{5 0 - n m}$</tex> metamorphic high-electron-mobility-transistor (mHEMT) technology extending the D-band <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(110-170 \text{GHz})$</tex> are demonstrated. The optimization of the matching networks in D-band for lowest noise and high gain is discussed. LNA 1 utilizes a grounded co-planar waveguide environment with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$30 \mu ~\mathrm{m}$</tex> ground-to-ground spacing, while LNA 2 is investigating how the noise performance can be improved by using a lower loss input matching network with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$50 \mu ~\mathrm{m}$</tex> ground-to-ground spacing. LNA 1 achieves an average in-band gain of 27.7 dB over a broad bandwidth of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$96-168 \text{GHz}$</tex>, with an average noise temperature of 343 K (3.4 dB noise figure). LNA 2 operates between <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$98-170 \text{GHz}$</tex> with an average small-signal gain of 25.4 dB and an measured average noise temperature of 325 K <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(3.2 ~\text{dB})$</tex> between <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$107-170 \text{GHz}$</tex>. To the best of the authors' knowledge, this is the lowest noise performance demonstrated over the full D-band by an LNA at room temperature.