RFID temperature logger incorporating a frequency ratio digitizing temperature sensor
US7474230B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2006 |
| Grant date | Jan 6, 2009 |
| Priority date | — |
| Expiry date | Dec 8, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K7/01
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A semi-passive radio frequency identification (RFID) tag being coupled to a battery providing a battery voltage for powering a part of the circuitry of the RFID tag includes an RF communication block receiving and transmitting RF signals, a sensor block including a frequency ratio digitizing temperature sensor for alternately measuring the ambient temperature and the battery voltage, and a control logic block in communication with the RF communication block and the sensor block. The control logic controls the operation of the RF communication block and the sensor block and stores temperature and voltage measurement data generated by the sensor block. In one embodiment, the control logic block of the RFID tag operates based on a system clock and the sensor block provides a reference clock to the control logic block for use in calibrating the system clock of the control logic block.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.