Oscillator with phase-noise cancellation
AssigneeAnritsu Corporation
InventorOleksandr Chenakin
Life of this patent
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Abstract
Circuits, methods, and apparatus that can provide oscillator circuits that have reduced phase noise. An example can provide a yttrium-iron-garnet oscillator in a loop with a loop amplifier and a phase-shift circuit. The yttrium-iron-garnet oscillator can act as a resonator. Quadrature outputs of the yttrium-iron-garnet oscillator can drive a phase detector that can provide a control signal to the phase-shift circuit. The phase-shift circuit can then reduce or cancel phase noise in the loop, thereby enabling the loop to provide a reference signal having reduced phase noise.
Claims18
An oscillator circuit comprising:
- a resonator circuit having an input, an in-phase output, and a quadrature output, wherein the resonator circuit comprises a yttrium-iron-garnet oscillator having a first coupling coil coupled between the input and the in-phase output, a second coupling coil coupled between ground and the quadrature output, and a yttrium-iron-garnet sphere between the first coupling coil and the second coupling coil;
- a phase detector having a first input coupled to the in-phase output of the resonator circuit and a second input coupled to the quadrature output of the resonator circuit;
- a phase-shift circuit having a control input coupled to an output of the phase detector;
- and
- a loop amplifier coupled to the resonator circuit and the phase-shift circuit.
An oscillator circuit comprising:
- a yttrium-iron-garnet oscillator comprising a first coupling coil coupled between an input and a first output, a second coupling coil coupled between ground and a second output, and a yttrium-iron-garnet sphere between the first coupling coil and the second coupling coil, wherein the first output and the second output of the yttrium-iron-garnet oscillator provide quadrature signals;
- a loop circuit coupled around the yttrium-iron-garnet oscillator, the loop circuit comprising:
- a loop amplifier;
- and
- a phase-shift circuit, the loop amplifier and phase-shift circuit coupled in series and coupled to the input of the yttrium-iron-garnet oscillator;
- and
- a feedback loop comprising:
- a phase detector having a first input coupled to the first output of the yttrium-iron-garnet oscillator, a second input coupled to the second output of the yttrium-iron-garnet oscillator, and an output coupled to a control input of the phase-shift circuit.
A phase-locked loop comprising:
- an oscillator circuit;
- a first phase detector having a first input coupled to an output of the oscillator circuit;
- a low-pass filter having an input coupled to an output of the first phase detector;
- an amplifier having an input coupled an output of the low-pass filter;
- a voltage controlled oscillator having an input coupled to an output of the amplifier;
- and
- a divider having an input coupled to an output of the voltage controlled oscillator and an output coupled to a second input of the first phase detector, wherein the oscillator circuit comprises:
- a yttrium-iron-garnet oscillator;
- a loop circuit comprising a loop amplifier and a phase-shift circuit coupled between a first output of the yttrium-iron-garnet oscillator and an input of the yttrium-iron-garnet oscillator;
- and
- a feedback loop comprising a second phase detector having a first input coupled to the first output of the yttrium-iron-garnet oscillator, a second input coupled to a second output of the yttrium-iron-garnet oscillator, and an output coupled to a control input of the phase-shift circuit.
Dependencies are inferred from the claim text.