Vibration compensated interferometric noise suppressed oscillator (INSO)

An interferometric noise suppressed oscillator (INSO), comprising:

• an amplifier, a loop phase shifter responsive to a control signal, and a resonator arranged in a loop to oscillate and produce a first signal at a carrier frequency, a second signal produced by reflection of a portion of the first signal by the resonator;
• a carrier suppression circuit responsive to the first and second signals to produce a carrier suppressed signal, a mixer responsive to the carrier suppressed signal and the first signal to produce an error signal corresponding to the phase difference between the first and second signals, wherein the error signal responds linearly to changes in the carrier frequency,
• said carrier suppression circuit including a phase shifter responsive to a tuning voltage to adjust the carrier frequency;
• a control signal generator including a feedback amplifier that amplifies the error signal to provide the control signal to the loop phase shifter to suppress close-in phase noise near the carrier frequency;
• and
• a vibration sense circuit configured to produce a vibration compensation signal indicative of mechanical vibrations, the vibration compensation signal being summed with the error signal that is fed to the control signal generator to reduce the effects of mechanical vibrations on oscillator phase noise independent of the tuning voltage applied to the phase shifter.

A method of suppressing effects on oscillator phase noise in an interferometric noise suppressed oscillator (INSO) due to external vibrations, wherein an interferometric noise suppressed oscillator (INSO), the method comprising:

• sensing one or more accelerations of the INSO;
• producing a vibration compensation signal responsive to the one or more accelerations;
• summing the vibration compensation signal with an error signal at an output of a mixer in the INSO, wherein the error signal responds linearly to changes in a carrier frequency;
• and
• applying the vibration compensation and error signals to a feedback amplifier in the INSO to provide a control signal to a loop phase shifter in the INSO to suppress close-in phase noise near the carrier frequency and to reduce the effects of mechanical vibrations on oscillator phase noise.