Voltage controlled oscillators
US6683509B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2002 |
| Grant date | Jan 27, 2004 |
| Priority date | — |
| Expiry date | Aug 20, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/099
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency synthesiser comprises a voltage controlled oscillator, VCO, having means for fine tuning the oscillator frequency and switchable capacitive elements for coarse tuning the oscillator frequency. First comparison means are provided for comparing the frequency and phase of the output of the VCO or a signal derived therefrom with that of a reference frequency signal to provide an error signal, the error signal being provided to said means for fine tuning the oscillator frequency. Second comparison means are provided for comparing the error signal against one or more reference values and a control means receives the result of the comparison from the second comparison means and switches said switchable capacitive elements on and off in dependence upon the result so as to coarse tune the oscillator frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.