Transponder location and tracking system and method
US5227803A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1992 |
| Grant date | Jul 13, 1993 |
| Priority date | — |
| Expiry date | Jul 22, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S5/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A transponder location and tracking system having a phased array antenna mounted at a toll collection station includes a plurality of antenna array elements for receiving a signal from a transponder mounted on a vehicle and for providing a plurality of antenna element electrical signals. A plurality of phase detectors are provided for comparing the phase of the electrical signals to provide a plurality of phase difference signals. A plurality of angle-of-arrival calculation processors is provided for converting the phase difference signals to spatial signals to define the angles-of-arrival of the vehicle transponder signal. A position calculation processor is included for providing an output signal representative of the location of the vehicle in response to the defined angles-of-arrival. In a preferred embodiment, the transponder location and tracking system includes a plurality of receiver processing devices for amplifying and filtering the electrical signals from each antenna element. The phase detectors then compare the phase of the electrical signals to a reference element signal. Each phase detector provides a digital representation of the phase difference signals. The spatia…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.