Relative Design Merits and Trends in Single-Ended Ring Voltage Controlled Oscillators

摘要

Voltage controlled oscillator (VCO) is one of the most crucial components in nanometer-scale circuits for communication systems. Wide tuning range, low power demand and high operating frequency are the key features that researchers tend to focus on while designing VCOs for submicron CMOS architectures. Reported topologies of oscillators reveal the existence of two widely employed VCO designs: the inductor-capacitor (LC) VCO and the ring VCO. This review article focuses on the single-ended ring oscillator (SERO), which is classified into different categories based on topology and performance. Along with basic architectures, state-of-the-art designs that have been proposed over the years are discussed in details highlighting their relative merits. Their performances are compared and presented in a tabular form in terms of key design figures which demonstrates that modifying existing SEROs typically requires trade-offs among oscillating frequency, power dissipation, tuning range and phase noise. The analysis also suggests the application specific use of the different architectures with respect to these properties. The comprehensive review will be a suitable literature for future work.