Adjustable array antenna
US5905473A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 31, 1997 |
| Grant date | May 18, 1999 |
| Priority date | — |
| Expiry date | Mar 31, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q3/2635
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A passive reflective antenna located near an active receiving antennas is used to change the energy at the receiving antenna. The change in energy may be such as to remove a null created by multipath or to provide directionality, or both. The receiving antennas is permanently connected to a single receiver. When the receiver's output signal degrades below an acceptable level of quality, the reflective phase of the passive antenna's load is changed to change the phase of the reflected energy and achieve a desired effect (remove a null, change directionality, etc.) at the receiving antenna. In the simplest embodiment, the termination of the passive antenna is switched from an open circuit to a short circuit, or vice versa, to invert the phase of the reflected energy. The use of reflective elements in antenna designs, usually to achieve directionality, is well known (see the common Yagi or corner reflector antenna designs, for example), but these use passive reflector elements. The present invention, in contrast, employs active control of the reflective element. The term "reflective element" is used to mean an element that re-radiates RF energy. The position of a reflective element re…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.