TVRO receiver system with low-cost video-noise reduction filter
US4876739A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1987 |
| Grant date | Oct 24, 1989 |
| Priority date | — |
| Expiry date | Dec 31, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/52
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A TVRO receiver for receiving frequency-modulated video signals, the receiver comprising a tuner including a superheterodyne circuit having a voltage-controlled oscillator (VCO), means for supplying a controlling input voltage to the VCO, and a mixer for combining incoming 1st IF signals with the output of the VCO to reduce the frequency of the 1st IF signals to a 2nd IF frequency which is sufficiently high to permit the output frequency of the VCO to be above the frequency range of the 1st IF signals, and a linear phase passband filter for passing a single video channel in the 2nd IF output from the mixer, the filter producing an output which is at least about 10 dB down from its peak at both +10 MHz and -10 MHz from the center of the passband of the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.