Compensation for oscillator tuning gain variations in frequency synthesizers
US6724265B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 14, 2002 |
| Grant date | Apr 20, 2004 |
| Priority date | — |
| Expiry date | Jun 14, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0898
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A system is provided for compensating for tuning gain variations in a phase lock loop. Compensation is performed by a calibration system that estimates the tuning gain of the oscillator and then adjusts the charge pump current value by a ratio of the nominal tuning gain to the measured tun gain. The tuning gain measurement is performed by measuring the change in the voltage controlled oscillator's tuning control voltage when the phase lock loop is locked to two different frequencies, which are separated by a fixed, predetermined amount. The two frequencies may be above or below the final output frequency of the VCO, or the second frequency may be the final frequency in order to reduce calibration time and settling time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.