A Wide Tuning Range Low $\pmb{K}_{\mathbf{VCO}}$ and Low Phase Noise VCO

A wide tuning range, low K
_VCO
and low phase noise VCO is presented in this paper by combining fully differential active inductor (DAI), switched capacitor array and MOS-based variable capacitors. The adoption of the DAI instead of spiral inductor in the LC tank reduces the phase noise of VCO due to high Q value of DAI. The multiple tuning modes by tunable active inductor, switched capacitor array and variable capacitor make VCO have a wide tuning range of oscillation frequency and lower K
_VCO
. Based on TSMC 0.18μm CMOS process, the VCO is verified by Advanced Design System (ADS). The results show that the oscillation frequency can be tuned from 988MHz to 4601MHz with a wide tuning bandwidth of 129.3%, and the lowest phase noise is -116.88dBc/Hz at 1MHz offset, and the K
_VCO
is as low as 45-550MHz/V.