A novel high speed CMOS pseudo-differential ring VCO with wide tuning control voltage range

In this paper a novel three-stage pseudo-differential ring voltage controlled oscillator (VCO) based on Park-Kim ring VCO with high speed and a wide tuning control voltage range is proposed. By using the inductive shunt peaking technique with Hara active inductors a wide bandwidth is obtained. A pair of PMOS transistors with gates connected to the controlled-voltage is added to increase the oscillation frequency and tuning control voltage range. The phase noise is also reduced by minimizing signal transition period in which noise current has critical impact on the phase noise. The circuit is simulated in 0.18 µm CMOS technology with supply voltage of 1.8V and power consumption of 8.3mW. A VCO with wide tuning frequency range from 3.1 GHz to 10.1 GHz is achieved by using this technique. The measured phase noise of this ring VCO are −113 dBc/Hz at a 1-MHz offset.