Analysis and Simulation of Phase Noise in Distributed Oscillators

In this paper, the phase noise of a CMOS distributed oscillators is formulated and simulated. A frequency-domain analytical method is employed for the phase noise formulation with the aid of a linear model. The thermal noise and flicker noise (1/f) are considered as the principal noise source contributors. Closed form formulae obtained for predicting distributed oscillator phase noise reveal circuit design issues with regard to phase noise. Harmonic balance (HB) simulation in Agilent advanced design system (ADS) is used to validate the developed formulae. Phase noise plots based on analytical formulae and simulation show a good agreement.