Phase noise of oscillators with unsaturated amplifiers.
We study the role of amplifier saturation in eliminating feedback noise in self-sustained oscillators. We extend previous works that use a saturated amplifier to quench fluctuations in the feedback magnitude, while simultaneously tuning the oscillator to an operating point at which the resonator nonlinearity cancels fluctuations in the feedback phase. We consider a generalized model which features an amplitude-dependent amplifier gain function. This allows us to determine the total oscillator phase noise in realistic configurations due to noise in both quadratures of the feedback, and to show that it is not necessary to drive the resonator to large oscillation amplitudes in order to eliminate noise in the phase of the feedback.
Department of Physics, California Institute of Technology, Pasadena, California 91125, USA.
Eyal
E
Kenig
Department of Physics, California Institute of Technology, Pasadena, California 91125, USA.
M C
MC
Cross
Department of Mechanical Engineering, University of California, Santa Barbara, California 93106, USA.
Jeff
J
Moehlis
School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Kurt
K
Wiesenfeld