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 NFmin and 298.6-GHz GBW. The input matching range covers 47–73.4 GHz. The IP1dB 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.