Method for identifying the position of a portable transponder, and an antitheft system
US7034656B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 13, 2002 |
| Grant date | Apr 25, 2006 |
| Priority date | — |
| Expiry date | Jun 28, 2023 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60R25/24
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A method for the recognition of the proximity of a portable transponder (20) to a base station (2), comprises the steps of: the base station transmits a first test signal with a defined power, the transponder determines the field strength with which it received the first test signal, and transmits a response signal to the base station containing said field strength and the base station stores the same. The transponder transmits a second test signal with a defined power, the base station determines the field strength with which it receives the second test signal and determines, from a comparison of the two field strengths, whether the transponder is in the vicinity thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.