A Wide Tuning Range and Low Phase Noise VCO using New Capacitor Bank Structure

This paper presents a wide tuning range, and low noise voltage controlled oscillator (VCO) based on cross-coupled and colpitts structures. The advantages of this work provide a low-phase noise and robust start-up condition, leading to minimized the dc power. In addition, a new structure of the capacitor bank is used in this structure to achieve a wide range of frequency. The proposed circuit is simulated in 0.18 μm CMOS process. The designed VCO covers the frequency range of 21.95 GHz to 24 GHz with a tuning range of 8.9%. Simulation results show that the phase noise is -120.5 dBc/Hz at 1MHz offset frequency for 23GHz carrier frequency. Also, power consumption of the VCO is 6.34 mW under 1.8 supply voltage, and the figure-of-merit is -191.68 dBc/Hz.