Self-calibration method for a frequency synthesizer using two point FSK modulation
US7982510B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 5, 2009 |
| Grant date | Jul 19, 2011 |
| Priority date | — |
| Expiry date | Oct 5, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03C3/0991
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The frequency synthesizer for implementing a self-calibration method includes (i) a first phase lock loop comprising: a reference oscillator, a phase comparator, a first charge pump, a first loop filter, a voltage controlled oscillator, and a multimode divider counter controlled by a modulator and connected to the phase comparator; (ii) a high frequency access comprising a digital-analogue converter connected to an input of the voltage-controlled oscillator; (iii) a second charge pump connected to the phase comparator; and (iv) a second loop filter in the high frequency access. The second charge pump forms, when switched on, a second phase lock loop with the second loop filter. To calibrate gains of the converter, a voltage comparator compares an output voltage of the converter with a voltage stored in the second loop filter, after disconnecting the second charge pump from the second phase lock loop, previously locked onto a determined output frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.