A C-Band CMOS Window-Shaped-Inductor-Based LC-VCO With Wideband Dual Common-Mode Resonance Technique

Abstract

This letter proposes a C-band dual-mode window-shaped-inductor-based LC-VCO using a wideband dual common-mode (CM) resonance technique. The proposed inductor with mode-switching functionality enables dual-mode operation to extend the frequency tuning range (TR). To reduce phase noise (PN), the dual CM resonance technique is employed, which provides high input impedance across the whole second harmonic band. Fabricated in a 65-nm CMOS process, the proposed oscillator exhibits 58.6% TR from 4.02 to 7.35 GHz. In $1/f^{2}$ region, the peak PN at 10-MHz offset is −151 dBc/Hz, corresponding to a figure-of-merit (FoM) of 192.7 dBc/Hz and FoMT of 208.1 dBc/Hz. In $1/f^{3}$ region, the VCO exhibits a low flicker PN corner of 320–370 kHz across the band. The VCO consumes about 12 mW and occupies a core area of 0.22 mm2.