Method and apparatus for waveform generation
AssigneeHRL Laboratories, LLC
InventorsDaniel Yap, Keyvan Sayyah
Life of this patent
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Abstract
A spread spectrum waveform generator has a photonic oscillator and an optical heterodyne synthesizer. The photonic oscillator is a multi-tone optical comb generator for generating a series of RF comb lines on an optical carrier. The optical heterodyne synthesizer includes first and second phase-locked lasers, where the first laser feeds the multi-tone optical comb generator and the second laser is a single tone laser whose output light provides a frequency translation reference. At least one photodetector is provided for heterodyning the frequency translation reference with the optical output of the photonic oscillator to generate a spread spectrum waveform. A receiver pre-processor may be provided to operate on the spread spectrum waveform.
Claims10
A frequency-modulated spread spectrum waveform generator comprising:
- (a) a generator for generating a frequency modulated optical waveform;
- (b) a comb generator for generating an optical comb;
- (c) an optical coupler combining frequency modulated optical waveform and the optical comb;
- and
- (d) at least one photodetector for heterodyning the output of the optical coupler wherein the comb generator comprises multiple loops including:
- (i) a first optical delay line in a first loop for spacing a comb generated by the multi-tone optical comb generator;
- (ii) a second optical delay in a second loop line for noise reduction, the second delay line being longer than the first optical delay line;
- (iii) at least one photo detector connected to the first and second delay lines;
- and
- (iv) an optical intensity modulator in a loop portion common to the first and second loops for driving the first and second optical delay lines.
A frequency-modulated spread spectrum waveform generator comprising:
- (a) a generator for generating a frequency modulated optical waveform;
- (b) a comb generator for generating an optical comb;
- (c) an optical coupler combining frequency modulated optical waveform and the optical comb;
- and
- (d) at least one photodetector for heterodyning the output of the optical coupler,
- wherein the generator for generating a frequency modulated optical waveform comprises two slave lasers and an amplitude or intensity modulated master laser for optically injection locking the two slave lasers to the master laser, the master laser being driven by a frequency-modulated signal.
Dependencies are inferred from the claim text.