Passive hybrid sensing tag with flexible substrate saw device
US8339219B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 2010 |
| Grant date | Dec 25, 2012 |
| Priority date | — |
| Expiry date | Apr 22, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K11/265
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The integration of surface acoustic wave (SAW) filters, microfabricated transmission lines, and sensors onto polymer substrates in order to enable a passive wireless sensor platform is described herein. Incident microwave pulses on an integrated antenna are converted to an acoustic wave via a SAW filter and transmitted to an impedance based sensor, which for this work is a photodiode. Changes in the sensor state induce a corresponding change in the impedance of the sensor resulting in a reflectance profile. Data collected at a calibrated receiver is used to infer the state of the sensor. Based on this principal, light levels were passively and wirelessly demonstrated to be sensed at distances of up to about 12 feet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.