A low phase noise ring oscillator phase-locked loop for wireless applications

Abstract

This thesis describes the circuit level design of a 900MHz [Sigma][Detta] ring oscillator based phase-locked loop using 0.35[mu]m technology. Multiple phase noise theories are considered giving insight into low phase-noise voltage controlled oscillator design. The circuit utilizes a fully symmetric differential voltage controlled oscillator with cascode current starved inverters to reduces current noise. A compact multi-modulus prescaler is presented, based on modified true single-phase clock flip-flops with integrated logic. A fully differential charge pump with switched-capacitor common mode feedback is utilized in conjunction with a nonlinear phase-frequency detector for accelerated acquisition time.