Design and Investigative Aspects of RF-Low Power 0.18-µm based CMOS Differential Ring Oscillator

Abstract

This manuscript presents the designing and investigative aspects of a low power, wide frequency range, and delay cell based 3 and 5-stage ring oscillator for RF-Ultra-WideBand application. The wide range of frequency is achieved by using two variable voltage sources i.e. control voltage source (Vcntrl) and tail current source (Vtail). A tail current improvement is responsible to control the charging and discharging time of oscillator. Moreover, the push-pull configuration is also used to attain high frequency. In addition, the proposed work presents the effect of control voltage and tail current source on the oscillator frequency. This work establishes a relation between oscillator frequency and its power consumption. This work also gives a comparison between 3stage and 5-stage ring oscillator. The circuit is implemented in 180 nm CMOS process provided by TSMC. The designed oscillator is measured to cover a frequency range of 1.3 – 5.7 GHz for 3-stage and 1.99 – 3.12 GHz for 5-stage ring oscillator. The simulated circuit draws 0.510 mW of average power for 3-stage ring oscillator and 0.719 mW average power for 5-stage ring oscillator.