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US 7,460,746 B2Granted
Tunable multi-loop opto-electronic oscillator with tunable RF or microwave filter based on optical filtering
AssigneeOEwaves, Inc.
InventorsLutfollah Maleki, Danny Eliyahu, Vladimir Ilchenko
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Abstract
Multi-loop opto-electronic oscillators using tunable RF or microwave filters that achieve signal filtering in RF or microwave frequencies by optical filtering and signal tuning by optical tuning.
Claims20
A device, comprising:
- a light source to produce an optical beam at an optical carrier frequency;
- an optical modulator to modulate the optical beam in response to a control signal to produce a modulated optical beam that carries the control signal;
- a plurality of signal loops to respectively receive loop signals derived from portions of the modulated optical beam;
- a plurality of adjustable phase shifters coupled in the signal loops, respectively, to control respective phase shifts of the loop signals;
- a mechanism to combine the loop signals from the signal loops and to produce a feedback signal in the electrical domain;
- and
- a tunable photonic electrical filter to filter the feedback signal to produce a filtered feedback signal as the control signal received by the optical modulator, wherein the tunable photonic electrical filter comprises a second optical modulator which converts the feedback signal into an optical signal, and wherein the tunable photonic electrical filter optically filters the optical signal and tune a frequency of the filtered optical signal to tune a frequency of the control signal.
4 more elements
A device, comprising:
- a laser to produce a laser beam at a laser carrier frequency;
- an optical modulator to modulate the laser beam in response to an input signal, which is electrical, to produce a modulated laser beam that carries the input signal;
- a plurality of optical delay lines to respectively receive portions of the modulated laser beam from the optical modulator;
- a plurality of optical detectors coupled to receive light beams from the optical delay lines, respectively, and to produce detector outputs;
- a plurality of voltage controlled phase shifters coupled to receive the detector outputs, respectively, to control phase shifts of the detector outputs;
- a signal combiner to combine the detector outputs from the voltage controlled phase shifters into a combined signal;
- and
- a tunable photonic RF or microwave filter to filter the combined signal to produce a filtered signal as the control signal to the optical modulator, wherein the tunable photonic RF or microwave filter comprises a second optical modulator which converts the combined signal into an optical signal, and wherein the tunable photonic RF or microwave filter optically filters the optical signal to tune a frequency of the filtered signal.
5 more elements
Dependencies are inferred from the claim text.