Low Power, Ring VCO with Pre-Charge and Pre-Discharge Circuit for 4GHz-6.1 GHz Applications in 0.18 μm CMOS

摘要

The differential ring voltage controlled oscillator (VCO) is one of the critical devices in wireless communication system having excellent stability, controllability and noise rejection ability. A novel design of delay cell is proposed for the four staged CMOS differential ring VCO with high output frequency, low power consumption and low phase noise. The differential ring VCO utilizes multiloop dual delay path topology to acquire both high output frequency and low phase noise. Results have been achieved in TSMC 0.18-mu m CMOS process with a supply voltage (V-dd) 1.8 V. The proposed design achieves an output frequency range of 4.029GHz to 6.122GHz and power of 4.475mW is consumed with control voltage variation from 1V to 2V. The proposed VCO exhibits -89.7 dBc/Hz phase noise at 1MHz offset frequency and the corresponding figure of merit (FoM) is -155.9 dBc/Hz. The design of differential ring VCO with novel delay stage has improved performance in terms of power consumption, output oscillation frequency and phase noise.