2011 Volume E94.A Issue 2 Pages 568-573
A novel resonant circuit consisting of transformer-based switched variable inductors and switched accumulation MOS (AMOS) varactors is proposed to realize an ultrawide tuning range voltage-controlled-oscillator (VCO). The VCO IC is designed and fabricated using 0.11µm CMOS technology and fully evaluated on-wafer. The VCO exhibits a frequency tuning range as high as 92.6% spanning from 1.20GHz to 3.27GHz at an operation voltage of 1.5V. The measured phase noise of -120dBc/Hz at 1MHz offset from the 3.1GHz carrier is obtained.