Digital channel selection and fine tuning system
US4298988A · kind A · utility
12Cited by
5References
7Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 10, 1979 |
| Grant date | Nov 3, 1981 |
| Priority date | — |
| Expiry date | Aug 10, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J5/0263
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A tuning system for use in a radio frequency multi-signal receiving system, e.g., for CATV converters, utilizes a closed feedback loop digital arrangement for channel selection (local oscillator frequency control) and channel fine tuning. The system may be implemented either via discrete hardware or through the use of microprocessor controlled apparatus. In accordance with one aspect of the present invention, double heterodyne tuning apparatus automatically compensates for frequency drift in the second local oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.