Feedforward notch filter
US6556080B1 · kind B1 · utility
3Cited by
7References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 13, 2001 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | Dec 13, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/3223
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A feedforward amplifier and notch filter (150) according to the present invention uses a direct coupling of an amplifier stage (158) with the amplifier's load (RL). The main amplifier (202) is coupled through a transmission line (210) to the load. This direct coupled amplifier stage (158) is driven by an signal that induces a very low impedance in parallel with the load at the receive frequency, but appears as an open circuit at the desired frequencies so that the desired signal from the main amplifier is virtually unaffected while output components at the receive frequency are cancelled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.