RFID SENSOR TAG AND SYSTEM FOR SMALL OUTPUT TRANSDUCERS,AND RELATED METHODS

• US 20150083810A1
• Filed: 09/14/2014
• Published: 03/26/2015
• Est. Priority Date: 09/22/2013
• Status: Active Grant

• Current Assignee: Lenlok Holdings, LLC
• Original Assignee: Lenlok Holdings, LLC
• Inventors: Ching, Larry, Lektomiller, Joseph Michael
• Granted Patent: US 9,378,448 B2
• Time in Patent Office: Days
• US Class Current: 235/492
• CPC Class Codes: G06K 19/0715 the arrangement including means to regulate power transfer to the integrated circuit
• CPC Class Codes: G06K 19/0716 at least one of the integrated circuit chips comprising a sensor or an interface to a sensor
• CPC Class Codes: G06K 7/10198 setting parameters for the interrogator, e.g. programming parameters and operating modes

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.

Claims

1. Method of creating a stable voltage input to a transducer associated with an RFID sensor tag, comprising:

amplifying a very small signal from the transducer and filtering RF noise out of the desired signal.

2. The method of claim 1, further comprising:

providing for transducer temperature compensation.

3. The method of claim 1, further comprising:

performing a calibration procedure.

4. The method of claim 1, further comprising:

storing an initial reading and subsequent measurement history in the sensor tag.

5. The RFID sensor tag and related method (and system) of claim 1, further comprising at least one of:

providing a stable voltage input to the transducer;

amplifying a very small signal from the transducer;

filtering RF noise out of the desired signal;

separating the sensing element from the RFID chip;

providing circuitry on the chip to isolate the sensor from RF noise; and

increasing the ability to measure low voltage (micro amps) with a passive circuit

6. An RFID sensor tag comprising an RFID IC with sensor input , and further comprising one or more of:

a precision voltage reference;

an RF filter that blocks the voltages that are created by the RFID reader RF field inducing currents into the circuit traces;

any resistive sensor or transducer;

a very low power consumption amplifier; and

an RF filter that blocks the voltages that are created by the RFID reader RF field inducing currents into the circuit traces.

7. The RFID sensor tag of claim 6, further comprising at least one of:

means for providing a stable voltage input to the transducer;

means for amplifying a very small signal from the transducer;

means for filtering RF noise out of the desired signal;

means for separating the sensing element from the RFID chip;

means for providing circuitry on the chip to isolate the sensor from RF noise; and

means for increasing the ability to measure low voltage (micro amps) with a passive circuit