RFID Sensor Tag And System For Small Output Transducers, And Related Methods
First Claim
1. A wireless, temperature calibration method to bulk calibrate a plurality of RFID sensors prior to use of said RFID sensors, or during a re-calibration process of said RFID sensors after a period of use, where each RFID sensor comprises an RFID IC with sensor input from a transducer that outputs a signal indicative of a parameter to which an object associated with the RFID sensor is subjected, the method comprising the steps of:
- placing said plurality of RFID sensors in a test system where a known input can be applied and resulting output can be measured and recorded, the test system further including a RFID reader;
subjecting each of said plurality of RFID sensors to a predetermined parameter;
subjecting each of said plurality of RFID sensors to a predetermined temperature;
transmitting, using the RFID reader, an interrogation signal to each of said plurality of RFID sensors in the test system, the interrogation signal inducing supply voltage in each of said plurality of RFID sensors;
receiving, at the RFID reader, resulting output signals indicative of the parameter and temperature that is experienced by each respective RFID sensor, wherein said output signals are transmitted from the antenna of each respective one of said plurality of RFID sensors;
determining separate calibration constants for each respective one of said plurality of RFID sensors; and
storing said separate calibration constants in a memory of each respective one of said plurality of RFID sensors.
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Accused Products
Abstract
A battery-free wireless sensor system enables high resolution and very accurate measurements of strain or other transducers with small signal outputs. The system may comprise a sensor tag, associated readers and data processing. The sensor tag may be based on passive RFID, or other passive devices that are powered by RF energy and that communicate with the powering source by backscatter, inductive coupling or reflected energy. The system may include a reader that powers the sensor tags with RF energy and that also wirelessly reads data from and writes data to the sensor tag. The reader software or host software may perform operations on the data that enable more accurate and useable information from the sensor tag. The invention may also include methods for data processes that improve the functionality and performance of the sensor system.
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Citations
20 Claims
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1. A wireless, temperature calibration method to bulk calibrate a plurality of RFID sensors prior to use of said RFID sensors, or during a re-calibration process of said RFID sensors after a period of use, where each RFID sensor comprises an RFID IC with sensor input from a transducer that outputs a signal indicative of a parameter to which an object associated with the RFID sensor is subjected, the method comprising the steps of:
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placing said plurality of RFID sensors in a test system where a known input can be applied and resulting output can be measured and recorded, the test system further including a RFID reader; subjecting each of said plurality of RFID sensors to a predetermined parameter; subjecting each of said plurality of RFID sensors to a predetermined temperature; transmitting, using the RFID reader, an interrogation signal to each of said plurality of RFID sensors in the test system, the interrogation signal inducing supply voltage in each of said plurality of RFID sensors; receiving, at the RFID reader, resulting output signals indicative of the parameter and temperature that is experienced by each respective RFID sensor, wherein said output signals are transmitted from the antenna of each respective one of said plurality of RFID sensors; determining separate calibration constants for each respective one of said plurality of RFID sensors; and storing said separate calibration constants in a memory of each respective one of said plurality of RFID sensors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification