Partial modification of a nominal impedance using digital impedance synthesis
US6456665B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1999 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | May 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/0002
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A circuit is provided for creating a termination impedance which matches a characteristic impedance. The characteristic impedance of a system or network is matched by placing a nominal impedance across the transmission line. The difference between the nominal impedance and the characteristic impedance is synthesized such that the synthesized or generated impedance is in parallel with the nominal impedance. The parallel combination of the nominal impedance and the generated impedance produces a termination impedance which substantially matches the characteristic impedance. The generated impedance is created by sensing a voltage and scaling that voltage by a factor related to the nominal and characteristic impedances. The scaled voltage controls a current source which produces a current having a value related to the inverse of the impedance. The ration of the sensed voltage and the generated current is the impedance which, when combined with the nominal impedance, produces the desired termination impedance. In this manner, the characteristic impedance of the source is matched by the altered nominal impedance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.