A simple, unified phase noise model for injection-locked oscillators

Abstract

This paper presents a simple, unified phase noise model for injection-locked oscillators (ILO). We show that an ILO is identical to a type-I first-order PLL in its noise behavior within the lock range. The model predicts the phase noise of injection-locked oscillators (ILO), injection-locked frequency dividers (ILFD), and injection-locked frequency multipliers (ILFM) as a function of the injection source phase noise and the oscillator phase noise. Measurement results from a discrete 57MHz Colpitts ILO, an integrated 6.5GHz ILFD, and an integrated 24GHz ILFM are presented to validate the theoretical predictions.