Canceling tradeoff between phase noise and phase error in parallel coupled quadrature oscillators

Abstract

This paper presents an analytic approach for the estimation of the phase imbalances duo to mismatch between two LC-tank of oscillators. We derive equations with different coupling factors for the two coupled LC oscillators for more generality. We show that choosing appropriate inversely proportional coupling factors makes it possible to have exactly zero phase error. Choosing so hasn't any impact on phase noise, indeed the tradeoff between phase noise and phase error in coupled quadrature oscillators have been broken here. The theoretical results and proposed quadrature oscillator are evaluated and confirmed through simulations using TSMC 0.18 µm model technology on a 5-GHz quadrature oscillator with 1.8 V supply voltage.