A 50-70.9-GHz LNA with Defectly-Coupled-Transformer Achieving Sub-4 DB NF and 298.6-GHZ GBW for 5GNR-FR2-2 and SATCOM

This paper presents a sub-4-dB NF 50-70.9 GHz LNA with a defectly coupled transformer. The source-to-gate coupled feedback in the input transformer network is inhibited for wideband simultaneous noise and input matching. A coupling canceling structure is utilized to reduce the specific coupling in a tri-coupled transformer. Verified in a conventional 40-nm bulk CMOS process, the proposed LNA achieves 3.5 dB <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$NF_{min}$</tex> and 298.6-GHz GBW. The input matching range covers 47-73.4 GHz. The <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$IP_{1dB}$</tex> is measured as −14.5 dBm, while consuming 33 mW. Benefited from the defectly coupled transformer, the proposed LNA demonstrates the highest figure of merit (FoM) compared to state-of-the-arts mm-wave LNAs.