Opto-electronic phase-locked loop with microwave mixing for clock recovery
First Claim
1. A dock recovery circuit for synchronizing a clock signal having frequency of approximately f0 with an optical data signal having a frequency of N×
- f0, where N is an arbitrary rational number, comprising;
a local oscillator for generating said clock signal;
a sampler for producing an output signal indicative of a phase difference between said clock signal and said optical data signal;
an optical detector coupled to detect said output signal as an electrical signal; and
a mixer for isolating at least one harmonic of said electrical signal and for downconverting said at least one harmonic to a baseband error signal,wherein said local oscillator is tuned in response to said baseband error signal to synchronize said clock signal with said optical data signal.
6 Assignments
0 Petitions
Accused Products
Abstract
A clock recovery circuit for synchronizing a clock signal having frequency of approximately f0 with an optical data signal having a frequency of N×f0, where N is an arbitrary rational number, includes a local oscillator for generating the clock signal, a sampler for producing an output signal indicative of a phase difference between the clock signal and the optical data signal, an optical detector coupled to detect the output signal as an electrical signal, and a mixer for isolating at least one harmonic of the electrical signal and for downconverting the at least one harmonic to a baseband error signal. The local oscillator is tuned in response to the baseband error signal to synchronize the clock signal with the optical data signal.
13 Citations
24 Claims
-
1. A dock recovery circuit for synchronizing a clock signal having frequency of approximately f0 with an optical data signal having a frequency of N×
- f0, where N is an arbitrary rational number, comprising;
a local oscillator for generating said clock signal; a sampler for producing an output signal indicative of a phase difference between said clock signal and said optical data signal; an optical detector coupled to detect said output signal as an electrical signal; and a mixer for isolating at least one harmonic of said electrical signal and for downconverting said at least one harmonic to a baseband error signal, wherein said local oscillator is tuned in response to said baseband error signal to synchronize said clock signal with said optical data signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- f0, where N is an arbitrary rational number, comprising;
-
10. A method of synchronizing a clock signal having frequency of approximately f0 with an optical data signal having a frequency of N×
- f0, where N is an arbitrary rational number, comprising the steps of;
generating said clock signal with a local oscillator; sampling said optical data signal to produce an output signal indicative of a phase difference between said clock signal and said optical data signal; detecting said output signal as an electrical signal; isolating at least one harmonic of said electrical signal; downconverting said at least one harmonic signal to a baseband error signal, and tuning said local oscillator with said baseband error signal to synchronize said clock signal with said optical data signal. - View Dependent Claims (11, 12, 13, 14, 15, 16)
- f0, where N is an arbitrary rational number, comprising the steps of;
-
17. An optical transmission system adapted to receive a time division multiplexed optical data signal from a light source, said time division multiplexed optical data signal having a frequency of N×
- f0, where N is an arbitrary rational number and f0 is a tributary rate of component signals in said time division multiplexed optical data signal, said system comprising;
at least one node comprising a clock recovery circuit for synchronizing a clock signal having frequency of approximately f0 wit said time division multiplexed optical data signal, said clock recovery circuit comprising; a local oscillator for generating said clock signal; an electroabsorption modulator circuit for producing an output signal indicative of a phase difference between said clock signal and said optical data signal; an optical detector coupled to detect said output signal as an electrical signal; and a mixer for isolating at least one harmonic of said electrical signal end for downconverting said at least one harmonic to a baseband error signal, wherein said local oscillator is tuned in response to said baseband error signal to synchronize said clock signal with said data signal. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
- f0, where N is an arbitrary rational number and f0 is a tributary rate of component signals in said time division multiplexed optical data signal, said system comprising;
Specification