Systems and methods for correcting phase locked loop tracking error using feed-forward phase modulation
US6831491B2 · kind B2 · utility
71Cited by
13References
22Claims
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Key dates
| Filing date | Dec 23, 2002 |
| Grant date | Dec 14, 2004 |
| Priority date | — |
| Expiry date | Dec 23, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/087
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Tracking error in phase locked loop (PLL) devices is addressed utilizing feed-forward phase modulation. Specifically, the phase difference of the reference signal and said oscillator signal of a PLL may be determined utilizing a phase detector. The output of the phase detector may be provided to a loop filter to provide feedback to the VCO of the PLL. Additionally, the filtered phase difference may be provided to a suitably calibrated phase modulator to add an amount of phase modulation to the oscillator signal that is approximately equal and opposite to said phase difference to generate a corrected phase output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.