Transponder having microprocessor generated frequency shift signals
US5587712A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1993 |
| Grant date | Dec 24, 1996 |
| Priority date | — |
| Expiry date | Nov 12, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/825
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An improved transponder for use in identifying an controlling vehicles wherein transponders mounted on vehicles respond to signals from a fixed location interrogator providing information relative to the vehicle or other data as required. The transponder disclosed in particular utilizes an improved method of providing frequency shift keyed (FSK) signals in response to a trigger or command signal received from a ground mounted loop or antenna. As disclosed, the transponder of the invention generates FSK signals through programming multiple microprocessor loops of predetermined duration, each loop providing microprocessor highs and lows for transmission to the interrogating station. Utilization of the inherently accurate microprocessor cycle time to generate distinct FSK signals avoids problems with ordinarily used analog frequency generating devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.