Fixed and varactor-tuned bandstop filters with spurious suppression
US8912868B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 20, 2012 |
| Grant date | Dec 16, 2014 |
| Priority date | — |
| Expiry date | Mar 18, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01P7/088
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A bandstop filter configured to suppress a spurious resonance frequency includes a resonator and a transmission line that is coupled to the resonator at a first junction and at a second junction with a length θ of transmission line running between the two couplings. The configuration provides two signal paths so that constructive interference occurs at the spurious resonance, and destructive interference occurs at a fundamental bandstop frequency. This provides spurious suppression by effectively cancelling out resonator couplings via the constructive interference, extending the upper passband of the bandstop filter to any degree required by the application.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.