Device for measuring echo return loss in a two-two wire line system
US5943392A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 24, 1997 |
| Grant date | Aug 24, 1999 |
| Priority date | — |
| Expiry date | Jan 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/493
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention is directed to an adaptor for measuring an echo return loss in a communication system. The adaptor includes two transformers, each having a primary winding and two secondary windings. The secondary windings are cross-connected to form first and second out of phase circuits. The first circuit includes impedance elements which match an impedance of an external device. When the external device is attached to the second circuit, the first and second circuits are schematically equivalent, albeit out of phase. When an oscillation signal is input to one transformer, the matched impedance and out-of-phase connection of the secondary windings cancel the signal such that only an echo signal is output by the other transformer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.