Integrated tunable RF notch filter
US8428203B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 2009 |
| Grant date | Apr 23, 2013 |
| Priority date | — |
| Expiry date | Feb 22, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/10
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Large interfering signals (interferers) with spectra near a desired signal can cause distortion in a wireless receiver due to a non-linear signal path. It is typically a performance advantage to attenuate these interferers earlier in the signal path, rather than later in the signal path, because these interferers can cause saturation of amplifying stages. In certain situations, the frequency offset of an interfering signal, with respect to the desired signal, can be on the order of 10 megahertz (MHz), whereas the center frequencies can be on the order of several gigahertz (GHz). Thus, a filter with “baseband” precision would be needed at radio frequency to notch out the interferer, which is relatively difficult to do. Disclosed is a technique to estimate the relative strength and center frequency of the interferer and to place the center frequency of a notch filter adaptively and precisely at the interferer location.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.