Control circuit and method for direct current controlled attenuator
US5656978A · kind A · utility
18Cited by
5References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1995 |
| Grant date | Aug 12, 1997 |
| Priority date | — |
| Expiry date | Dec 11, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/24
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A bridge T attenuator which includes PIN diodes in both the bridge arm and in the shunt arm, and in which the current through the shunt arm is controlled with respect to the current through the bridge arm, so that the product of these two currents equals a constant. This is accomplished by a feedback loop. Thus a relatively simple, inexpensive, and entirely analog solution is provided for a bridge T attenuator to be used with a radio frequency signal, so that a prescribed level of attenuation set by a user may be maintained while the impedance is maintained at a fixed value over the entire attenuation range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.