Frequency synthesizer and method of operating the same
US10666271B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 2019 |
| Grant date | May 26, 2020 |
| Priority date | — |
| Expiry date | Jul 10, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/1976
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency synthesizer, comprises a phase frequency detector to receive a frequency signal and a reference clock, and to output a phase difference according to a phase difference and a frequency difference between the frequency signal and the reference clock; a charge pump to generate a current according to the phase difference; a loop filter to generate a first voltage signal based on the current; a N-path filter each comprising a switch, a path filter and to generate N paths of filtered voltages based on the first voltage; a voltage control oscillator to generate a second voltage signal based on a sum of the N paths of filtered voltages; a frequency divider to generate the frequency signal based on the second voltage signal and a variable frequency dividing ratio; and a Sigma-Delta Modulator to generate the variable frequency dividing ratio based on a digital representation of a frequency fractional value and the reference clock.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.