Design and Analysis of Low Power Ring Based Oscillator Circuits

Abstract

newline Voltage-controlled oscillators (VCOs) are widely used in many wired and wireless communication systems ranging from low-frequency generators to high-frequency RF synthesizers. In the last few years, wireless and optical communication systems have shown extensive growth. This tremendous growth has driven the need for more compact, fully integrated, and low power consumption VCO design. The design of high-performance VCO along with low-power consumption is essential and is an active research area.VCO performance is analyzed in terms of different performance parameters such as high spectral purity, wide operating range, low power consumption, and figure of merit. The design of a low-power and wide tuning range VCO with good phase noise performance is a critical task at each level of the designing process. In this research work, CMOS ring-based VCO circuits have been proposed in both the configuration single and differential ended with improved performance. It has been demonstrated that the proposed VCO circuits are better than the existing design in terms of power consumption and frequency range. newlineThe proposed ring VCO-1 consists of a delay stage that is designed with three transistors NOR gate along with frequency tuning element. Frequency tuning is achieved by varying the load elements by applying a variable tuning voltage. The VCO is designed and simulated in TSMC 0.18and#956;m CMOS technology. VCO-1 circuit provides a wide frequency range between 0.556 GHz to 2.584 GHz over a control voltage variation with a power consumption of 1.26mW. newlineThe proposed three-stage ring DCO-2 is a high-performance, digitally controlled, single-ended CMOS oscillator. The DCO-2 circuit is designed and simulated in TSMC 0.18and#956;m CMOS technology. Frequency variation is achieved by a digitally controlled tuning element. The digital control bit varies the driving current across the tuning element that causes to change in the oscillation frequency of the proposed DCO. A tunable range of frequency from 0.818 GHz to 0.872 GHz has....