PASSIVE RFID SENSOR TAG

• US 20160063286A1
• Filed: 08/31/2015
• Published: 03/03/2016
• Est. Priority Date: 09/03/2014
• Status: Active Grant

• Current Assignee: Metso Outotec Finland OY (Metso Outotec Oyj)
• Original Assignee: Metso Flow Control Oy (Neles Oyj)
• Inventors: NIKUNEN, Joona, VIIKARI, Ville
• Granted Patent: US 9,613,237 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 19/0717 the sensor being capable of sensing environmental conditions such as temperature history or pressure
• CPC Class Codes: G06K 7/10158 methods and means used by the interrogation device for reliably powering the wireless record carriers using an electromagnetic interrogation field

Abstract

An integrated passive radio frequency identification transponder chip includes a backscatter modulator for communication with a backscattering principle, a tag oscillator generating a backscattering modulation frequency, and a reference load, preferably a reference resonator. Either the reference load or at least one pair of an internal or external resonator and an external sensor element can be selectively connected to load the tag oscillator. Each external sensing element is arranged to sense a predetermined variable. The tag oscillator is capable of generating any one of nominal backscattering modulation frequencies defined for a respective RFID system, when the reference load is connected to load the tag oscillator. The tag oscillator is arranged to generate a predetermined one of nominal backscattering modulation frequencies, when the at least one pair of the internal or external resonator and the external sensor element is connected to load the tag oscillator.

Claims

1. An integrated passive radio frequency identification (RFID) transponder chip comprising

a rectifier generating an electric power for the chip from a received radio frequency (RF) signal,

a backscatter modulator for communication with a backscattering principle,

a tag oscillator for generating a backscattering modulation frequency,

a reference load,

selection means for selectively connecting either the reference load or at least one pair of an internal or external resonator and an external sensing element to load the tag oscillator, each external sensing element sensing a predetermined variable, and wherein

the tag oscillator is capable of generating any one of nominal backscattering modulation frequencies defined for a respective RFID system, when the reference load is connected to load the tag oscillator, and

the tag oscillator is arranged to generate a predetermined one of the nominal backscattering modulation frequencies, when the at least one pair of the internal or external resonator and the external sensor element is connected to load the tag oscillator.

3. A transponder chip as claimed in claim 1, wherein the backscattering modulation frequency of the tag oscillator is arranged vary dependent on a sensed value of the predetermined variable within an allowed frequency tolerance of said predetermined one of the nominal backscattering modulation frequencies.

4. A transponder chip as claimed in claim 1, comprising contact terminals to which at least one external sensing element and/or at least one pair of external sensing element and an external resonator can be connected.

5. A transponder chip as claimed in claim 1, comprising contact terminals to which at least one pair of external sensing element and an external LC resonator can be connected.

6. A transponder chip as claimed in claim 1, wherein the tag oscillator in combination with a pair of an external resonator and an external sensor element is an LC oscillator.

7. A transponder chip as claimed in claim 1, comprising an internal resonator and contact terminals to which an external sensing element can be connected to form a pair of the internal resonator and the external sensing element.

8. A transponder chip as claimed in claim 1, comprising an internal resonator and contact terminals to which an external capacitive sensing element can be connected to form a pair of the internal resonator and the external sensing element.

9. A transponder chip as claimed in claim 1, wherein the tag oscillator in combination with a pair of an internal resonator and an external sensor element is an RC oscillator.

10. A transponder chip as claimed in claim 1, wherein the tag oscillator in combination with the reference load is an RC oscillator.

11. A transponder chip as claimed in claim 1, wherein the backscattering modulation frequency of the tag oscillator in combination with the reference load is configured to have a predetermined temperature-frequency correlation.

12. A transponder chip as claimed in claim 1, wherein the reference load is a resonator or a temperature sensor or a combination thereof.

14. A transponder chip as claimed in claim 1, comprising additional energy storage, for harvesting and storing a larger amount of energy from the received RF signal over a longer period of time.

15. A transponder chip as claimed in claim 1, comprising an internal antenna and/or contact terminals which an external antenna can be connected to.

16. A transponder chip as claimed in claim 1, wherein the nominal backscattering modulation frequencies include one or more of 640 kHz, 320 kHz, 256 kHz, and 40 kHz.

2. An integrated passive radio frequency identification (RFID) transponder chip comprising

a rectifier generating an electric power for the chip from a received radio frequency (RF) signal,

a backscatter modulator for communication with a backscattering principle,

a tag oscillator arranged to generate a predetermined one of nominal backscattering modulation frequencies defined for a respective RFID system, when at least one external sensing element or at least one pair of an internal or external resonator and an external sensor element is connected to load the tag oscillator,

a reference oscillator capable of generating any one of the nominal backscattering modulation frequencies defined for a respective RFID system,

selection means for selecting either the reference oscillator or the tag oscillator to provide the backscattering modulation frequency to the backscattering modulator.

13. A transponder chip as claimed in claim 2, wherein the backscattering modulation frequency of the reference oscillator is configured to have a predetermined temperature-frequency correlation.

17. A passive radio frequency identification (RFID) sensor tag, comprising a carrier element, integrated passive RFID transponder chip attached on the carrier element, and at least one external sensing element and/or at least one external resonator attached on the carrier element and electrically connected to the contact terminals of the transponder chip, the integrated passive RFID transponder chip further comprising

a rectifier generating an electric power for the chip from a received radio frequency (RF) signal,

a backscatter modulator for communication with a backscattering principle,

a tag oscillator for generating a backscattering modulation frequency,

a reference load,

selection means for selectively connecting either the reference load or at least one pair of an internal or external resonator and an external sensing element to load the tag oscillator, each external sensing element sensing a predetermined variable, and wherein the tag oscillator is capable of generating any one of nominal backscattering modulation frequencies defined for a respective RFID system, when the reference load is connected to load the tag oscillator, and

the tag oscillator is arranged to generate a predetermined one of the nominal backscattering modulation frequencies, when the at least one pair of the internal or external resonator and the external sensor element is connected to load the tag oscillator.

18. A passive RFID sensor tag as claimed in claim 17, further comprising an external antenna attached the carrier element and electrically connected to the transponder chip.

19. A passive RFID sensor tag as claimed in claim 17, wherein the at least one external resonator comprises one or more of LC resonator, MEMS (microelectro-mechanical systems) resonator, SAW (surface acoustic wave) resonator, BAW (bulk acoustic wave) resonator.

20. A passive RFID sensor tag as claimed in claim 17, wherein the at least one external sensing element comprises one of more of a lightning sensor, a strain sensor, a wear sensor, a moist sensor, a pH sensor, a pressure sensor, a humidity sensor, a pressure sensor, a gas sensor, a quality sensor, a position sensor, a vibration sensor.

21. A passive radio frequency identification (RFID) sensor tag, comprising a carrier element, integrated passive RFID transponder chip attached on the carrier element, and at least one external sensing element and/or at least one external resonator attached on the carrier element and electrically connected to the contact terminals of the transponder chip, the integrated passive RFID transponder chip further comprising

a rectifier generating an electric power for the chip from a received radio frequency (RF) signal,

a backscatter modulator for communication with a backscattering principle,

a tag oscillator arranged to generate a predetermined one of nominal backscattering modulation frequencies defined for a respective RFID system, when at least one external sensing element or at least one pair of an internal or external resonator and an external sensor element is connected to load the tag oscillator,

a reference oscillator capable of generating any one of the nominal backscattering modulation frequencies defined for a respective RFID system,

selection means for selecting either the reference oscillator or the tag oscillator to provide the backscattering modulation frequency to the backscattering modulator.