Efficient object identification system
US4364043A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 1981 |
| Grant date | Dec 14, 1982 |
| Priority date | — |
| Expiry date | Sep 8, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/70
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A system for the remote identification of objects using near-field electromagnetic coupling between an interrogator a transponder and a receiver in which a reply carrier at a subharmonic of the interrogation frequency is obtained by regulating, with minimum energy loss and synchronously with the interrogator signal, the energy exchange process between the transponder coupling element and a complementary storage element, and further varying, also with minimum energy loss and synchronously with the resultant oscillation waveform, the said energy exchange process so that the reply carrier becomes modulated with an information bearing code, the modulation rate being not constrained by the transponder tuned circuit bandwidth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.