System and method for voltage controlled oscillator automatic band selection
US5648744A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1995 |
| Grant date | Jul 15, 1997 |
| Priority date | — |
| Expiry date | Dec 22, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0891
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A system and method for establishing the frequency of a voltage controlled oscillator ("VCO") within narrowly defined frequency bands. The resonant circuit of the VCO uses selectable elements, such as varactor diodes, to establish the operating frequency band. The control voltage of the VCO is varied within a voltage range to adjust the VCO output frequency. A phase detector compares the VCO output to a reference signal. If the phase detector determines that there is an imbalance between the VCO output and the reference signal, then it produces a signal which indicates whether the VCO frequency should be increased or decreased to match the reference signal frequency. If the control voltage is outside of the voltage range, then the system allows the operating frequency band to be changed by varying the number of selectable elements in response to the phase detector signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.