Power harvesting in a passive RFID device

• US 10,176,415 B2
• Filed: 10/12/2015
• Issued: 01/08/2019
• Est. Priority Date: 10/10/2014
• Status: Active Grant

• Current Assignee: Zwipe AS
• Original Assignee: Zwipe AS
• Inventors: Wendling, Jean-Hugues
• Primary Examiner(s): Marshall, Christle I
• Application Number:
  US15/515,785
• Publication Number:
  US 20180330216A1
• Time in Patent Office: 1,184 Days
• Field of Search: None
• CPC Class Codes: G06K 19/0708 the source being electromagnetic or magnetic
• CPC Class Codes: G06K 19/0709 the source being an interrogation field
• CPC Class Codes: G06K 19/0718 the sensor being of the biometric kind, e.g. fingerprint sensors fingerprint sensors in general G06V40/13; biometric access-control systems in general, see G07C9/00
• CPC Class Codes: G06K 19/07345 by activating or deactivating at least a part of the circuit on the record carrier, e.g. ON/OFF switches
• CPC Class Codes: G06K 19/07354 by biometrically sensitive means, e.g. fingerprint sensitive fingerprint sensors in general G06V40/12; biometrically activated access control G07C9/25

Abstract

A method of harvesting power in a passive RFID device including a passive biometric authentication engine, including the steps of receiving a command from a powered RFID reader and supplying power extracted from an excitation field of the RFID reader to the biometric authentication engine whilst the RFID reader waits for a response to the command. Responsive to determining that a period that the RFID device has been waiting for a response exceeds a predetermined threshold, and that a process being performed by the biometric authentication engine has not been completed, a request for a wait time extension is sent to the RFID reader to cause it to continue supplying the excitation field.

Claims

1. A method for harvesting power in a passive RFID device comprising a passive biometric authentication engine, the method comprising:

receiving, by the RFID device, a command from a powered RFID reader;

receiving, by the RFID device, a non-pulsing continuous radio-frequency excitation field whilst the RFID reader waits for a response to the command;

harvesting, by the RFID device, power from the excitation field;

supplying the power extracted from the excitation field to the biometric authentication engine;

performing a process in the biometric authentication engine, the process being one not required for responding to the command from the RFID reader;

determining a period that the RFID device has been waiting for a response; and

responsive to determining that the period exceeds a predetermined threshold, if the process has not been completed, sending, by the RFID device, a request for a wait time extension to the RFID reader.

2. A method according to claim 1, wherein the RFID device does not respond to the command whilst the biometric authentication engine is performing the process.

3. A method according to claim 1, further comprising:

after the biometric authentication engine completes the process, responding by the RFID device to the command.

4. A method according to claim 1, wherein the steps of determining a period and sending a request for a wait time extension to the RFID reader are repeated until the process is completed and/or a response to the command has been sent.

5. A method according to claim 1, wherein the period is a time since the command was received or since the last wait time extension request was made.

6. A method according to claim 1, wherein the process performed by the biometric authentication engine is a biometric enrolment process.

7. A method according to claim 1, wherein the process performed by the biometric authentication engine is a biometric matching process.

8. A method according to claim 1, wherein the process requires greater than 5.0 seconds to be completed.

9. A method according to claim 1, wherein the biometric authentication engine includes a biometric scanner and a processing unit.

10. A method according to claim 9, wherein the biometric authentication engine is a fingerprint authentication engine and the biometric scanner is a fingerprint scanner.

11. A method according to claim 1, wherein the RFID device is a proximity integrated circuit card (PICC) and the RFID reader is a proximity coupling device (PCD).

12. A method according to claim 11, wherein the predetermined threshold is less than a first wait time (FWT) of the PCD.

13. A passive RFID device comprising:

an antenna for receiving a radio-frequency excitation field from an RFID reader and for harvesting power from the excitation field;

a passive biometric authentication engine arranged to receive power harvested by the antenna; and

an RFID device controller arranged to perform a method, comprising;

receiving, by the antenna, a command from a powered RFID reader;

receiving, by the antenna, a substantially continuous radio-frequency excitation field whilst the RFID reader waits for a response to the command;

performing a process in the biometric authentication engine, the process being one not required for responding to the command from the RFID reader;

determining a period that the RFID device has been waiting for a response; and

responsive to determining that the period exceeds a predetermined threshold if the process has not been completed, sending by the antenna a request for a wait time extension to the RFID reader.

14. A passive RFID device according to claim 13, wherein the RFID controller is configured not to respond to the command whilst the biometric authentication engine is performing a process.

15. A passive RFID device according to claim 13, wherein the method further comprises:

after the biometric authentication engine completes the process, responding by the RFID device to the command.

16. A passive RFID device according to claim 13, wherein the steps of determining a period and sending a request for a wait time extension to the RFID reader are repeated until the process is completed and/or a response to the command has been sent.

17. A passive RFID device according to claim 13, wherein the period is a time since the command was received or since the last wait time extension request was made.

18. A passive RFID device according to claim 13, wherein the process performed by the biometric authentication engine is a biometric enrolment process.

19. A passive RFID device according to claim 13, wherein the process performed by the biometric authentication engine is a biometric matching process.

20. A passive RFID device according to claim 13, wherein the process requires greater than 5.0 seconds to be completed.

21. A passive RFID device according to claim 13, wherein the biometric authentication engine includes a biometric scanner and a processing unit.

22. A passive RFID device according to claim 21, wherein the biometric authentication engine is a fingerprint authentication engine and the biometric scanner is a fingerprint scanner.

23. A passive RFID device according to claim 13, wherein the passive RFID device is a proximity integrated circuit card (PICC) and the RFID reader is a proximity coupling device (PCD).

24. A passive RFID device according to claim 23, wherein the predetermined threshold is set to be less than a first wait time (FWT) of the PCD.