Battery assisted RFID tag with square-law receiver and optional part time active behavior
US9367711B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 2008 |
| Grant date | Jun 14, 2016 |
| Priority date | — |
| Expiry date | Dec 29, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/07749
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Embodiments of the present invention provide RFID systems having battery-assisted, Semi-Passive RFID tags that operate with sensitive transistor based square law tag receivers utilizing a plurality of tag receiver dynamic range states. Embodiments of the present invention are also enhanced with receiver training and synchronizing methods suited to the high tag sensitivity and need for dynamic range state switching. These enhancements may employ pseudo-random sequence based receiver training, activation signaling, and frame synchronizing. Further enhancement is achieved via design of system command sets and tag state machine behavior that control system interference and allow maximum usage of high sensitivity. Command set design also allows for convenient expansion to active transmitters and receivers in tags operating within the same system. Additional enhancement attained via power leveling methods that optimize the amount of transmitted power and interference from a reader in relation to the sensitivity of the RFID tags, their ranges from the reader, and the unique physics of the backscatter RFID radio link.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.