A Transformer Feedback ${G}_{m}$ -Boosting Technique for Gain Improvement and Noise Reduction in mm-Wave Cascode LNAs

This paper presents the analysis and design of a novel topology of a low-noise amplifier (LNA) with gain improvement and noise reduction simultaneously. A transformer feedback g
_m
-boosting technique is proposed in a single-ended cascode topology to increase the gain and reduce the noise. The proposed technique is theoretically formulated and detailed analyses are presented. Two V-band single-ended cascode LNAs, with a transformer and transmission line for impedance matching, respectively, are demonstrated to verify this technique. Fabricated in a 65-nm CMOS process, the transformer-based (TF-based) LNA exhibits a minimum noise figure (NF) of 3.6 dB at 53.5 GHz and a highest power gain of 28.2 dB at 54 GHz in measurement. To our best knowledge, this LNA has the best NF and power gain among all the published V-band LNAs in 65-nm CMOS up to date. The transmission-line-based (TL-based) LNA exhibits a minimum NF of 3.8 dB at 53.9 GHz and a highest power gain of 25.4 dB at 54.2 GHz in measurement. Both the LNAs consume 18 mA from a power supply of 1.1 V.