Satellite receiver
US5134707A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1990 |
| Grant date | Jul 28, 1992 |
| Priority date | — |
| Expiry date | Oct 23, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/1638
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Radio waves used in broadcasting and communications making use of broadcasting satellite and communication satellite are FM signals, and the frequency shift and exclusive bandwidth vary depending on the modulation signal. The satellite broadcasting receiver is designed to control the frequency shift so that the amplitude of the demodulation signal is constant, thereby making the bandwidth of the intermediate frequency filter, so as to be capable of receiving using just one filter. At this time, the frequency shift can be controlled continuously, from large to small one, in a predetermined exclusive bandwidth. When further expanding the frequency shift, since the exclusive bandwidth is extended, the noise electric power is increased and the receiving sensitivity is lowered as compared with the exclusive machine. Accordingly, when expanding the frequency shift, the noise bandwidth is narrowed in the PLL demodulator, thereby enhancing the receiving sensitivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.