Phase-locked loop capable of generating a plurality of stable frequency signals
AssigneeNorth American Philips Corporation
InventorsDouglas J. Hatch, Jeffrey L. Cox
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Abstract
A phase-locked loop capable of generating a plurality of stable frequncy signals. This loop includes a plurality of voltage controlled oscillators which are sequentially coupled to the output of a phase sensitive detector by a multiplexer. RF switches then sequentially couple, in synchronism with the multiplexer, the oscillator outputs to a programmable divider which, in turn, is coupled to an input of the phase sensitive detector, the other input thereto being coupled to a reference oscillator. The dividing factors for the programmable divider are inputted thereto, in synchronism with the multiplexer, from a memory.
Claims8
A phase-locked loop having a phase sensitive detector, a fixed frequency oscillator coupled to a first input of said phase sensitive detector, and variable oscillator means coupled to an output of said phase sensitive detector, said variable oscillator means having at least one output at which a stable frequency signal may be obtained, which output is coupled to a second input of said phase sensitive detector;
- characterized in that said variable oscillator means comprises N variable oscillators having N respective outputs, where N is an integer greater than 1;
- said phase-locked loop further comprising first means for alternatively coupling the output of said phase sensitive detector to said N variable oscillators, means coupled to the second input of said phase sensitive detector for determining, respectively, the frequency of the signal at each of said N variable oscillator outputs, and second means for alternatively coupling said N variable oscillator outputs to said frequency determining means in synchronism with said first coupling means.
Dependencies are inferred from the claim text.