Frequency agile filter using a digital filter and bandstop filtering
US8385871B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 26, 2009 |
| Grant date | Feb 26, 2013 |
| Priority date | — |
| Expiry date | Jan 16, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention is a hybrid RF-digital signal processor-based filter for multiband radio architectures systems capable of spectrum re-farming and software defined radios. It performs low-loss frequency agile multiple notch filtering at RF where a large dynamic range exists at a filter input between signals in a stopband and passband. It is a frequency dependent signal attenuation apparatus having two paths connected together by directional couplers. The first path comprising a component such as a delay component or duplexer. The second path comprising a bandstop filter connected to a down converter, a digital filter, and an up converter. At the output of a power amplifier, the invention can be used to attenuate spurs, or noise within bands with strict emission constraints. At the input of a low noise amplifier, the invention can be used to attenuate blockers and transmitter noise outside of the receiver passband.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.