An 82–107.6-GHz Integer- $N$ ADPLL Employing a DCO With Split Transformer and Dual-Path Switched-Capacitor Ladder and a Clock-Skew-Sampling Delta–Sigma TDC.

A W-band integer-N all-digital phase-locked loop (ADPLL) aiming for wide frequency tuning range (TR) and low phase noise is proposed. The W-band ADPLL employs a digitally controlled oscillator (DCO) with split transformer and dual-path exponentially scaled switched-capacitor ladder and a clock-skew-sampling delta–sigma time-to-digital converter (TDC). The 65-nm CMOS W-band ADPLL measures a frequency TR of 27% from 82 to 107.6 GHz and phase noise from −106 to −110 dBc/Hz at 10-MHz offset and −84 to −87 dBc/Hz at 100-kHz offset while consuming 35.5 mW and occupying a 0.36 mm2 core area, corresponding to a figure of merit (FOM) of −171 ~ −173 dB and FOMT of −178 ~ −181 dB. [ABSTRACT FROM AUTHOR]