Antenna duplexer with divided and grounded transmission line
US6489861B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 2001 |
| Grant date | Dec 3, 2002 |
| Priority date | — |
| Expiry date | Apr 26, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/725
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An antenna duplexer has a first filter and a second filter coupled to respective signal terminals and to a common node. The common node is coupled to an antenna terminal. The first filter has a higher-frequency passband than the second filter. A transmission-line circuit, inserted between the first filter and the common node, increases the impedance of the first filter in its lower stopband. The transmission-line circuit includes an internal node, a first transmission line coupling the internal node to the common node, a second transmission line coupling the internal node to the first filter, and a grounding circuit such as a capacitor coupling the internal node to ground. The grounding circuit further enhances the lower stopband impedance of the first filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.