Passive hybrid sensing tag with flexible substrate saw device
First Claim
1. A passive wireless sensor, comprising:
- a surface acoustic wave (SAW) filter;
an impedance changing element; and
an antenna matched to a microwave frequency;
wherein the SAW filter, impedance changing element and antenna are electrically interconnected and fixedly integrated onto a surface of a flexible substrate, wherein the SAW filter, impedance changing element and antenna are interconnected using a low melting point solder.
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Accused Products
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.
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Citations
11 Claims
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1. A passive wireless sensor, comprising:
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a surface acoustic wave (SAW) filter; an impedance changing element; and an antenna matched to a microwave frequency; wherein the SAW filter, impedance changing element and antenna are electrically interconnected and fixedly integrated onto a surface of a flexible substrate, wherein the SAW filter, impedance changing element and antenna are interconnected using a low melting point solder. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification