Phase noise reduction in quadrature LC oscillators using inverter-based Tail noise shaping

Abstract

A technique to reduce the Phase Noise of a Quadrature Differential Oscillator is described. The technique uses inverters to shape the tail noise of differential oscillators. In this approach an inverter is used to increase the "squareness" of the switching signal from the differential output and thereby improve the switching speed. Simulations are done to obtain the results to verify the new technique. The simulation tool used is Eldo RF in Mentor Graphics and the technology used is UMC 0.18 um process.