Tuner
US6968173B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 15, 2002 |
| Grant date | Nov 22, 2005 |
| Priority date | — |
| Expiry date | Oct 29, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/099
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A tuner comprises a frequency changer which converts an input signal to a predetermined fixed intermediate frequency. The frequency changer is followed by an IF filter having a filter parameter, such as center frequency, which is electronically adjustable. A controller adjusts the adjustable filter characteristic so as to achieve a predetermined desired filtering performance, such as ensuring that the filter center frequency corresponds to the desired intermediate frequency. The controller comprises a local oscillator having the same type of tuned circuit as the IF filter. A phase locked loop compares the local oscillator frequency with a reference frequency and controls the tuned circuits of the IF filter and the local oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.