Design and Optimization of Differrential Ring Oscillator for IR-UWB Applications in 0.18 μm CMOS Technology

This study presents a two-stage ring voltage-controlled oscillator (VCO) for use in impulseradio ultra-wideband (IR-UWB) applications. A systematic and effcient graphical optimization method was employed to find the optimal dimensions of the VCO which give a best performance. A good agreement was observed between the desired specifications and simulation results with regard to the optimum component size of the VCO circuit. The operation range of the VCO was extended to cover an ultra-wide tuning range of 176.6%. The phase noise was-107.1 dBc/Hz at 10MHz or set frequency from a carrier frequency of 4 GHz. The power consumption of VCO was 7.41 mW from a 1.8V supply voltage. A large tuning range, low power, and appropriate phase noise were obtained with the optimum components size obtained through the optimization method.