Compact antenna for circular polarization
US5786793A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1997 |
| Grant date | Jul 28, 1998 |
| Priority date | — |
| Expiry date | Aug 8, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q21/24
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A compact antenna for circular polarization comprises a substrate of a dielectric material which is formed on its bottom surface with a ground plane and on its top surface with four planar rectangular patches of an electrically conductive material. The four patches are mounted in a coplanar relation on the top surface of the substrate, and arranged along four sides of a square pattern with the length of each patch angled at 90.degree. with respect to the length of the two adjacent patches. Each of the four patches is short-circuited to the ground plane at a shorting point located at a corner of the square pattern. A 90.degree. hybrid circuit is connected to directly feed only the two adjacent patches with a phase difference of 90.degree. to thereby define these two patches as active antenna elements which are fed with 0.degree. and 90.degree. signals, respectively. The other two adjacent patches are not fed from the hybrid circuit to define parasitic antenna elements each coupled with the adjacent active antenna element to provide a signal which is 90.degree. out of phase with a signal on the adjacent active antenna element. Thus, the active and parasitic antenna elements arranged …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.