Phase noise of oscillators with unsaturated amplifiers

Area of Science:

• Physics
• Electrical Engineering
• Nonlinear Dynamics

Background:

• Self-sustained oscillators are crucial in various electronic systems.
• Feedback noise can degrade oscillator performance.
• Previous methods focused on quenching feedback magnitude fluctuations.

Purpose of the Study:

• To investigate amplifier saturation's role in eliminating feedback noise in self-sustained oscillators.
• To analyze noise cancellation in both feedback magnitude and phase.
• To develop a generalized model for realistic oscillator configurations.

Main Methods:

• Utilizing a saturated amplifier to quench feedback magnitude fluctuations.
• Tuning the oscillator to an operating point where resonator nonlinearity cancels feedback phase fluctuations.
• Employing a generalized model with an amplitude-dependent amplifier gain function.

Main Results:

• Demonstrated that amplifier saturation effectively eliminates feedback noise.
• Showed that resonator nonlinearity cancels feedback phase fluctuations.
• Determined total oscillator phase noise in realistic configurations.
• Proved that large oscillation amplitudes are not necessary for phase noise elimination.

Conclusions:

• Amplifier saturation is a viable strategy for noise reduction in oscillators.
• Resonator nonlinearity plays a key role in phase noise cancellation.
• The generalized model provides insights into realistic oscillator noise performance.