Sampling system for radio frequency receiver
US5841814A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 17, 1995 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Oct 17, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/46
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A radio frequency (rf) receiver adapted to receive a number of different digitally modulated rf input signals such as quadrature amplitude modulated (QAM) and vestigial side band (VSB) rf input signals includes circuitry for down converting the rf input signals to an intermediate frequency (IF) range having a center frequency fc2 and a bandwidth of Bhz and converter circuitry for sampling the IF signals and then producing corresponding baseband signals. In a preferred embodiment, the intermediate frequency signals are applied to a sample and hold circuit which is sampled at a frequency fs and whose output is coupled via a low pass filter to an analog-to-digital converter whose output is then applied to a Hilbert filter for demodulating the sampled signals and producing baseband signals. In-phase (I) and quadrature (Q) signals are produced whose phase and amplitude are not a function of different components and their tolerance of different conduction paths, as in the prior art.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.