Directional receiver coupling arrangement with frequency selectivity and gain control for DSL
US7123897B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 2004 |
| Grant date | Oct 17, 2006 |
| Priority date | — |
| Expiry date | Apr 2, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/0002
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A directional coupler for a modem has a high common mode noise rejection characteristic with low transmit signal leakage, and reduced distortion of components mixed with a received signal. A primary filter network is connected to a communications circuit. The primary filter network has an output connected to an input of an amplifier. A feedback network is connected between the input and output of the amplifier. The primary filter network, the amplifier and the feedback network are arranged to provide a virtual ground at the input of the amplifier, and a filter characteristic which attenuates frequencies in the transmit signal band. The advantage is reduced component count while providing excellent transmit signal rejection and reducing received signal distortion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.