Roadside beacon system with polarized beams
US4983984A · kind A · utility
11Cited by
4References
2Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 25, 1987 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Nov 25, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08G1/096758
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In a roadside beacon system for transmitting to vehicles moving along roads, signals on position and direction, linearly polarizing antennas mounted to be stationarey either beside or above the roads and other linearly polarizing antennas mounted to be mobile on the vehicles. The downwardly transmitting stationary and the upwardly receiving mobile antennas have matching linear polarizations when the vehicle is traveling on the road adjacent to the antenna but a mobile antenna will have reduced sensitivity when moving on a road at a different angle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.