RFID tags calibrating backscattering period also for non-integer divide ratios
US7246751B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 2005 |
| Grant date | Jul 24, 2007 |
| Priority date | — |
| Expiry date | Dec 27, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/0723
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An RFID tag that receives a calibration instruction from a reader can determine the basic backscatter period of the symbols to be backscattered. According to some embodiments, when the instruction includes a calibration feature that is to be divided by a divide ratio, the tag measures the duration of the feature in terms of numbers of internal pulses, resulting in a binary L-number. Then at least two versions of the L-number (PR1-number, PR2-number) are combined, so as to yield the effective result of the division alternately, even when the divide ratio is a non-integer. The backscatter period can then be determined from the BP-number and the period of the internal pulses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.