Antenna apparatus
US5784034A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1997 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Jan 27, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q21/29
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Herein is revealed a helical antenna apparatus wherein the direction of beam radiation hardly changes even if the frequency in use changes. Two helical antennas which are wound with two conductive wires spirally, respectively, at equal intervals with a specified pitch .alpha. in the form of a cylinder are disposed along the length of the helical antennas so that the axes thereof substantially coincide with each other. By determining the lengths of the feeders of the respective helical antennas appropriately in order to set the phase of supplied power, it is possible to form the beam of signals radiated into space in the shape of conical beam having a directivity oriented obliquely upward. Additionally, it is possible to obtain the conical beam in which the direction of beam radiation does not change even if the frequency in use is changed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.