PLL system and method for controlling a gain of a VCO circuit
US8912857B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 2008 |
| Grant date | Dec 16, 2014 |
| Priority date | — |
| Expiry date | Sep 21, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/18
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A phase locked loop system, comprises: a voltage controlled oscillator circuit, comprising a first plurality of switchable varactors for selecting a frequency band of the VCO, that has a gain that changes with frequency band, and a second plurality of switchable varactors for varying the gain in the selected band. The PLL system has a PLL feedback circuit comprising a switching device for switching the feedback circuit to an open loop state wherein a plurality of predefined tuning voltages can be applied to the VCO; a frequency measurement device for measuring the synthesized VCO frequency; and a control unit operable to determine the gain with respect to the synthesized frequency and the tuning voltages.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.