Frequency changer and digital tuner
US6895063B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 2000 |
| Grant date | May 17, 2005 |
| Priority date | — |
| Expiry date | Jun 10, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/28
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A zero or near zero IF frequency changer for use in a digital tuner comprises multipliers which receive the RF input signal from an input. The multipliers receive quadrature local oscillator signals from a first oscillator of an arrangement which comprises first and second phase-locked loops. The first phase-locked loop comprises a programmable divider, a comparator and a control loop so that the first oscillator is phase-locked to a second oscillator. A second phase-locked loop comprises the second oscillator and a synthesizer containing a reference oscillator to which the second oscillator is phase-locked. The output frequency of the second oscillator is in a frequency band which is outside the RF input frequency band of the frequency changer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.