Frequency conversion circuit for a color television channel
US4974086A · kind A · utility
5Cited by
10References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 31, 1989 |
| Grant date | Nov 27, 1990 |
| Priority date | — |
| Expiry date | May 31, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/64
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A color television channel that includes a video channel and at least one sound channel is converted by means of a low-IF converter from the RF band directly to the baseband by analog quadrature conversion. The quadrature output signals are digitized. A correcting stage eliminates the quadrature errors and forms a corrected quadrature pair which drives a video stage and a sound conversion stage. The sound conversion stage includes at least one sound channel converter which converts the low-IF sound channel to its baseband by another (digital) quadrature conversion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.