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

Abstract

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-[Formula: see text]m CMOS process with a supply voltage ([Formula: see text]) 1.8[Formula: see text]V. The proposed design achieves an output frequency range of 4.029[Formula: see text]GHz to 6.122[Formula: see text]GHz and power of 4.475[Formula: see text]mW is consumed with control voltage variation from 1[Formula: see text]V to 2[Formula: see text]V. The proposed VCO exhibits [Formula: see text]89.7[Formula: see text]dBc/Hz phase noise at 1[Formula: see text]MHz offset frequency and the corresponding figure of merit (FoM) is [Formula: see text]155.9[Formula: see text]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.