Multiband phase locked loop using a switched voltage controlled oscillator
US5909149A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 1997 |
| Grant date | Jun 1, 1999 |
| Priority date | — |
| Expiry date | Aug 29, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/099
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A multi-band phase locked loop employing multiple, switchable voltage controlled oscillators. A single PLL is provided having a different voltage controlled oscillator for each desired frequency band of operation. The transfer function of the phase detector in the phase locked loop is switched responsive to the particular band selected so as to maintain the loop natural frequency at the same point regardless of other changes in the loop transfer function that are associated with operating at alternate frequencies, such as, but not limited to, changes in the frequency slope of the voltage controlled oscillators and changes in the division ratio of the loop divider circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.