Dual frequency launcher for circularly polarized antenna
US4872211A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 10, 1988 |
| Grant date | Oct 3, 1989 |
| Priority date | — |
| Expiry date | Aug 10, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q5/45
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A dual frequency antenna feed is formed from a central, circular waveguide onnected to the flat boundry of circular, disk-shaped resonant cavity. A second circular waveguide is connected one end of a disk-shaped resonant cavity. Energy of one frequency enters and exits the cavity along the common axis of the waveguides. Energy of the second frequency is introduced to the same resonant cavity by way of a plurality of bandpass filters, also connected to the cavity. This energy enters by way of slots in the cylindrical walls of the cavity. The central circular waveguide is propagating at one frequency but cut off at the second frequency. These bandpass filters are at this pass band for the second frequency, but at the rejection band for the first frequency. Therefore, the isolation between these two input ports are obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.