Radio receiving apparatus for receiving communication signals of different bandwidths
US6104764A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 1999 |
| Grant date | Aug 15, 2000 |
| Priority date | — |
| Expiry date | Dec 8, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D3/007
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A received signal obtained from an antenna is subjected to high-frequency amplification. The amplified signal is supplied to a first bandpass filter, which extracts only signals of all the channels of a communications system concerned while filtering out other radio signals. The extracted signals are frequency-converted by using a local oscillation frequency, and only a desired wave is passed by a second bandpass filter. The desired wave is supplied to a sample-and-hold circuit, which performs sampling according to the bandwidth-limiting sampling theorem. A resulting discrete signal is supplied to an I-axis-component and Q-axis-component separating circuits, where the polarity of sample values is inverted for every other clock pulse with respect to each of the I and Q axes to thereby effect Hilbert transform. Resulting two orthogonal components on a phase plane are supplied to a complex coefficient filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.