Combined active impedance and filter in line drivers
US6566947B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 26, 2000 |
| Grant date | May 20, 2003 |
| Priority date | — |
| Expiry date | Mar 12, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/30
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A line driver combining active impedance and filter in one stage for connection to a transmission line having a characteristic impedance. The line driver comprises an amplifier, a transformer with a primary to secondary winding ratio of 1:n, a reference impedance, an input impedance and two feedback impedances. The primary winding of the transformer has a first end connected to the output of the amplifier and the secondary winding is connectable to the transmission line. The reference resistor has an end connected to the second end of the first winding at a junction node and the feedback circuit is connected to the input and output of the amplifier and also to the junction node. The reference impedance has a value equal to times the characteristic impedance of the transmission line. The feedback circuit is arranged to produce a voltage at the output of the amplifier substantially equal to (K+1) times the voltage at the junction node, for a predetermined value of K. This results in output impedance equal to n2 times the characteristic impedance of the transmission line. At the same time, the gain or filter function is set by the specifying the ratio of feedback impedance to the inpu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.