Digital broadcasting receiver
US5956098A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1996 |
| Grant date | Sep 21, 1999 |
| Priority date | — |
| Expiry date | Aug 12, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N11/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
To make it possible to receive a modulated signal which is obtained by suppressing a carrier signal such as a high definition TV signal which is digitally demodulated such as QAM (quadrature amplitude modulation), a receiver of the double super-heterodyne system having the first and second mixers 9 and 13 is a basic constitution. A band pass filter having a flatness in pass band and a small deviation of group delay which will prevent the demodulation of a high definition TV signal from degradation is used a first intermediate frequency filter 11. An SAW filter is used as a second intermediate frequency filter 16. The third mixer 28 for converting a second intermediate frequency signal to a third intermediate frequency signal in frequency is installed and the frequency of the third intermediate frequency signal to be converted is set to a value lower than the frequency of the second intermediate frequency signal. The demodulator 33 for a high definition TV signal is installed so as to demodulate a high definition TV signal included in the third intermediate frequency signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.