RFID-based devices and methods for interfacing with a sensor
View Patent ↗A sensor is provided with an RFID reader, RFID chip, and an antenna electrically coupled to the RFID chip and configured to received signals from and transmit signals to the RFID reader. A sensing material is also electrically connected to the RFID chip and has a variable electrical property. The RFID chip is configured to modulate a signal received by the antenna and drive the sensing material using the modulated signal.
1. A sensor system, comprising:
an RFID reader;
an RFID chip;
an antenna electrically connected to the RFID chip and configured to receive signals from and transmit signals to the RFID reader;
and a resonant sensing circuit comprising a resonant circuit having a resonant frequency electrically connected to the RFID chip and whose resonant frequency is affected by an environmental characteristic of interest to correspondingly generate a variable resonant frequency indicative of said environmental characteristic of interest;
wherein the RFID chip is configured to modulate a signal received by the antenna from said reader by reducing the frequency thereof and drive the resonant sensing circuit using the modulated signal to obtain sensing circuit output from said variable resonant frequency to provide a response back to the RFID reader, and the antenna is configured to have an impedance which remains substantially uniform during use of the sensor system.
2. The sensor of claim 1 , wherein the resonator comprises an inductor and a capacitor.
3. The sensor system of claim 1 , wherein the RFID chip is configured to receive a signal from the resonant sensing circuit, an input impedance of the RFID chip is modulated based at least in part on the signal from the resonant sensing circuit, and the RFID chip backscatters a signal to the RFID reader via the antenna.
4. The sensor system of claim 1 , wherein the RFID chip is configured to directly analyze the condition of the resonant sensing circuit and send a signal to the RFID reader via the antenna.
5. The sensor of claim 1 , wherein the antenna comprises a UHF antenna.
6. The sensor system of claim 1 , wherein the RFID chip is configured to drive the resonant sensing circuit using a modulated signal having a defined voltage and a varying frequency.
7. A method for operating a sensor, comprising:
providing the sensor including an RFID chip, an antenna electrically connected to the RFID chip, and a resonant sensing circuit comprising a resonant circuit having a resonant frequency electrically connected to the RFID chip and whose resonant frequency is affected by an environmental characteristic of interest to correspondingly generate a variable resonant frequency indicative of said environmental characteristic of interest;
wherein the RFID chip is configured to modulate a signal received by the antenna from said reader by increasing the frequency thereof and drive the resonant sensing circuit using the modulated signal to obtain sensing circuit output from said variable resonant frequency to provide a response back to the RFID reader,
the antenna has an impedance which remains substantially uniform during use of the sensor;
sending the signal from the RFID reader to the RFID chip via the antenna;
modulating the signal by the RFID chip to generate the modulated signal by increasing the frequency thereof;
driving the resonant sensing circuit using the modulated signal to obtain a sensing circuit output from said variable resonant frequency to provide a response back to the RFID reader by the RFID chip.
8. The method of claim 7 , wherein said providing a sensor includes providing a sensing material comprising an inductor and a capacitor.
9. The method of claim 7 , further comprising: sending a signal from the resonant sensing circuit to the RFID chip, thereby modulating an input impedance of the RFID chip based at least in part on the signal from the resonant sensing circuit; and
backscattering a signal from the RFID chip via the antenna to provide said response.
10. The method of claim 7 , further comprising:
directly analyzing the condition of the resonant sensing circuit by the RFID chip; and
sending a signal based at least in part on the condition of the resonant sensing circuit via the antenna to provide said response.
11. The method of claim 7 , wherein said providing the sensor includes providing a UHF antenna.
12. The method of claim 7 , wherein said driving the resonant sensing circuit includes driving the resonant sensing circuit using a modulated signal having a defined voltage and a varying frequency.
13. A sensor system, comprising:
an RFID reader;
an RFID chip;
an antenna electrically connected to the RFID chip and configured to receive signals from and transmit signals to the RFID reader;
and a resonant sensing circuit comprising a resonant circuit having a resonant frequency electrically connected to the RFID chip and whose resonant frequency is affected by an environmental characteristic of interest to correspondingly generate a variable resonant frequency indicative of said environmental characteristic of interest;
wherein the RFID chip is configured to modulate a signal received by the antenna from said reader by increasing the frequency thereof and drive the resonant sensing circuit using the modulated signal to obtain sensing circuit output from said variable resonant frequency to provide a response back to the RFID reader, and the antenna is configured to have an impedance which remains substantially uniform during use of the sensor system.
14. A method for operating a sensor, comprising:
providing the sensor including an RFID chip, an antenna electrically connected to the RFID chip, and a resonant sensing circuit comprising a resonant circuit having a resonant frequency electrically connected to the RFID chip and whose resonant frequency is affected by an environmental characteristic of interest to correspondingly generate a variable resonant frequency indicative of said environmental characteristic of interest;
wherein the RFID chip is configured to modulate a signal received by the antenna from said reader by reducing the frequency thereof and drive the resonant sensing circuit using the modulated signal to obtain sensing circuit output from said variable resonant frequency to provide a response back to the RFID reader,
the antenna has an impedance which remains substantially uniform during use of the sensor;
sending the signal from the RFID reader to the RFID chip via the antenna;
modulating the signal by the RFID chip to generate the modulated signal by increasing the frequency thereof;
driving the resonant sensing circuit using the modulated signal to obtain a sensing circuit output from said variable resonant frequency to provide a response back to the RFID reader by the RFID chip.