Method and apparatus for effecting a wireless exchange of data between a stationary station and moving objects
US5757285A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1996 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Dec 11, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08G1/017
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A method for effecting a wireless exchange of data between a stationary station and transmitter/receivers on board objects, particularly vehicles moving relative to the stationary station. The reception profiles of an antenna array having a plurality of receiving antennas is directed electronically onto an object. The transmitter/receivers on the object transmit, in response to the received signal, an answer signal having the same carrier frequency as the signal received and having a level which is proportional to the level of the signal received. In the antenna array, a transmitting antenna is associated with each receiving antenna, and the transmitting antenna sends out signals having a transmission profile which corresponds to the reception profile of the receiving antenna. The damping factors of transmission profile and reception profile are thereby multiplied by each so that two relatively simple circuits are necessary in order to achieve a desired high side-lobe damping.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.