Low noise synthesizer and method employing first tunable source and first and second reference sources
US7005925B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 2002 |
| Grant date | Feb 28, 2006 |
| Priority date | — |
| Expiry date | Dec 13, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/23
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A low noise sinusoidal signal at a desired output frequency is synchronised using a first variable frequency oscillator (1) and providing a feedback control loop around the first oscillator (1) to generate a feedback control signal in successive frequ comparison steps using second and third frequency reference signals (44, 42). Each of the second and third frequency reference signals are derived from a first frequency reference signal, the second frequency reference signal (44) being compared with the output frequency of the first oscillator (1) to generate a frequency difference signal (43), and said frequency difference signal ( being compared in frequency with the third frequency reference signal (42) to generate said feedback control signal for the first oscillator (1), the frequency of the third frequency reference signal (42) being equal to the difference of the frequency of the se frequency reference signal (44) and the desired output frequency. The second and third frequency reference signals (44, 42) are generated by respective second and third frequency reference sources, the second frequency reference source comprising a second variable frequency oscillator (38) the freq…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.