Phase noise reduction by controlling biasing for adjustable oscillators with cross-coupled transistors

Abstract

Certain aspects of the present disclosure provide methods and apparatus for minimizing, or at least reducing, a bias noise contribution to phase noise in an oscillator circuit. One example oscillator circuit generally includes an oscillator configured to generate an oscillating signal, an adjustable bias circuit coupled to a bias input of the oscillator and configured to provide a bias signal to the oscillator, and a control circuit having an input coupled to an output of the oscillator and having an output coupled to a control input of the adjustable bias circuit. The control circuit is configured to control the adjustable bias circuit to adjust the bias signal with a control signal, to determine an impact of the adjusted bias signal on a parameter of the oscillating signal, and to determine a setting for the control signal based on the impact on the parameter of the oscillating signal.