Broad-band antenna structure having frequency-independent, low-loss ground plane
US4608572A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1982 |
| Grant date | Aug 26, 1986 |
| Priority date | — |
| Expiry date | Dec 10, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q9/28
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
To optimize antenna bandwidth and efficiency in broad-band antenna elements of the planar, multiarm spiral and log periodic types, a conically shaped ground plane characterized by progressively sized circumferential chokes, is arranged on a common axis with the axial center of the spiral or log periodic elements so that the electrical spacing between the excited regions of the log periodic of spiral elements and the ground plane maintains a constant one-quarter wavelength relationship. The progressively sized circumferential chokes on the ground plane cut off the flow of excessive radial currents along the ground plane surface to achieve an improved mix of excitation and reexcitation modes. In one embodiment, the circumferential chokes on the conical ground plane are partially shunted by shunting strips that electrically or capacitively bridge the choke walls to reestablish limited radial currents along the ground plane for sustaining certain desirable antenna modes. In another disclosed embodiment, the equivalent one-quarter wavelength relationship between the driven spiral or log elements and the reflecting ground plane is maintained in an antenna structure in which the driven el…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.