A W-Band Low-Noise Switched-Gm Down-Conversion Mixer with Gm-Boosting Feedback and Trifilar Transformer in 65-nm CMOS

This paper presents a W-band low-noise down-conversion mixer implemented in 65-nm CMOS technology. The proposed mixer employs a switched-transconductance (SwGm) architecture with DC-decoupled RF and LO stages, overcoming the frequency limitations of conventional SwGm topologies. Transformers provide magnetic coupling between stages, enabling gm boosting and wideband impedance matching of RF and LO ports. The transformer feedback of RF Gm stage enhances conversion gain while simultaneously reducing noise figure through partial noise cancellation. A pseudo-differential RF stage is adopted to improve linearity under limited voltage headroom. The LO stage noise is inherently cancelled in common mode, and sinusoidal switching minimises noise folding from the RF Gm stage. The mixer achieves 12.2 dB conversion gain, 5.0 dB noise figure, and 0.8 dBm IIP3 at 88 GHz, while consuming 6 mW from a 0.6-V supply. The measured results demonstrate excellent performance for W-band receiver applications.