Multi-transducer/antenna surface acoustic wave device sensor and tag
AssigneeUniversity of Central Florida Research Foundation, Inc.
InventorDonald C. Malocha
Life of this patent
Estimating the term…
Abstract
A surface acoustic wave sensor or tag having multiple transducer/antenna pairs each having a different center frequency. The bandwidth of each transducer/antenna pair is inversely proportional to the number of transducer/antennas pairs used and the bandwidth is the sum of the bandwidth of the transducer/antenna pairs. Implementing a SAW sensor or tag with multiple transducer/antenna pairs significantly reduces device losses and improves the performance of the device since the individual transducer/antenna pair's fractional bandwidth is reduced by the ratio of the system bandwidth to the number of transducer antenna pairs used in the sensor.
Claims20
A surface acoustic wave device comprising:
- a substrate;
- at least two banks of reflectors fabricated on said substrate for producing at least two contiguous stepped frequencies as an orthogonal coded signal, wherein each of said at least two contiguous stepped frequencies have a different center frequency within a bandwidth;
- and
- at least two transducer and antenna pairs each tuned to a corresponding one of the different center frequencies on said substrate, each of said at least two transducer/antenna pairs coupled with one of said at least two banks of reflectors for receiving an orthogonal frequency coded signal generated by a corresponding one of said at least two banks of reflectors, wherein the bandwidth of each transducer/antenna pair is inversely proportional to the number of transducer/antenna pairs used, and wherein the at least two transducer/antenna pairs output the orthogonal coded signal upon interrogation.
A system for identifying a surface acoustic wave device comprising:
- the device having at least two channels, each channel comprising:
- a bank of reflectors fabricated on said tag, so that the at least two channels produce at least two contiguous stepped frequencies as an orthogonal coded signal;
- plural transducer/antenna pairs, each transducer/antenna pair coupled with a different bank of reflectors for receiving an orthogonal interrogation signal, and transmits the orthogonal coded signal generated by said banks of reflectors for identifying said surface acoustic wave device in response to said orthogonal interrogation signal, wherein each of said transducer/antenna pairs and corresponding bank of reflectors having a different center frequency;
- and
- a transceiver in communication with said surface acoustic wave device for transmitting said orthogonal interrogation signal to said surface acoustic wave device and receiving said orthogonal coded signal from said surface acoustic wave device in response, wherein using multiple transducer/antenna pairs each having a different center frequency which increases the device bandwidth, reduces device loss and improves performance.
A method for producing a surface acoustic wave device comprising the steps of:
- applying at least two transceiver/antenna pairs to a substrate;
- fabricating plural reflector gratings on said substrate to form at least two banks of reflector gratings each of said at least two banks of reflector gratings coupled with a different one of said at least two transceiver/antenna pairs for producing at least two contiguous stepped frequencies as an orthogonal frequency coded signal, in response to an interrogation signal, each of said at least two transceiver/antenna pairs and corresponding bank of reflector gratings having a different center frequency.
Dependencies are inferred from the claim text.