Programmable frequency synthesizer having a low sensitivity to phase noise
US5880642A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 1997 |
| Grant date | Mar 9, 1999 |
| Priority date | — |
| Expiry date | Nov 21, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/181
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency synthesizer SYNT intended to supply an output signal Sout having an output frequency which depends on the average frequency, referred to as symbol frequency, of an input signal Sin beset with a strong phase noise. This synthesizer SYNT includes: a phase/frequency detector PHD comparing the symbol frequency with a predetermined fraction of the output frequency, and supplying a control signal; a low-pass filter LPF filtering the control signal; and an oscillator VCO supplying a signal Sout with a frequency which is adjusted by the filtered control signal Cs. Reference pulses having the symbol frequency are generated within the synthesizer SYNT by means of pulses from an internal clock, which pulses are validated by active states of the input signal Sin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.