Wide-band receiving apparatus with local oscillating circuit
US5630214A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1995 |
| Grant date | May 13, 1997 |
| Priority date | — |
| Expiry date | Mar 2, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/22
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A wide-band receiving apparatus used in an FM-FDM type optical image distributing system for transmitting multi-wave and multiple TV signals comprises a circuit for receiving a wide-band input signal containing modified RF signals of two or more different frequency bands and separating the RF signals by the bands; respectively, a first circuit for selecting one of the separated RF signals; a local oscillating circuit for generating a first oscillating signal of a fundamental frequency which is determined based on the frequency range of the selected RF signal; a circuit for producing at least one oscillating signal of a frequency having a predetermined ratio to the fundamental frequency; a second selecting circuit for selecting one of the first oscillating signal and at least one second oscillating signal; a circuit for mixing the selected RF signal with the selected oscillating signal thereby producing an intermediate-frequency signal; and a circuit for demodulating the intermediate-frequency signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.