A 1.3-2.8 GHz Wide Range CMOS LC-VCO Using Variable Inductor

This paper proposes a novel wide-range tunable CMOS voltage controlled oscillator (VCO). VCO uses an on-chip variable inductor and switched capacitors as variable elements. The VCO was fabricated using a standard 0.18μm CMOS process with five metal layers. The oscillation frequency can be tuned from 1.28 GHz to 2.75GHz with tuning range of 72%. The proposed VCO operates with low phase noise, and it achieves high FOMT -205.9 dBc/Hz.