RF device with tamper detection

• US 20110043339A1
• Filed: 08/19/2010
• Published: 02/24/2011
• Est. Priority Date: 08/19/2009
• Status: Active Grant

• Current Assignee: Zest Labs, Inc.
• Original Assignee: Intelleflex Corporation
• Inventors: McGregor, Michael
• Granted Patent: US 9,082,057 B2
• Time in Patent Office: Days
• US Class Current: 340/10.4
• CPC Class Codes: G06K 19/07372 by detecting tampering with the circuit
• CPC Class Codes: H04Q 2213/13095 PIN / Access code, authentication

Abstract

A Radio Frequency Identification (RFID) system according to one embodiment includes communication circuitry for enabling wireless communication with an RF reader; energy harvesting circuitry for generating an electric current from RF energy; a sensor loop coupled to the energy harvesting circuitry; and a status register coupled to the sensor loop for indicating a broken or unbroken status of the sensor loop. A method according to one embodiment includes generating an electric current in a Radio Frequency Identification (RFID) device, the current energizing a sensor loop; detecting a status of whether the sensor loop is broken or unbroken; storing the status in at least one of a status register and a nonvolatile memory; receiving a query from an RFID reader for the status; and sending the status to the RFID reader.

Claims

1. A Radio Frequency Identification (RFID) system, comprising:

communication circuitry for enabling wireless communication with an RF reader;

energy harvesting circuitry for generating an electric current from RF energy;

a sensor loop coupled to the energy harvesting circuitry; and

a status register coupled to the sensor loop for indicating a broken or unbroken status of the sensor loop.

2. The system of claim 1, wherein the RFID system is passive.

3. The system of claim 1, wherein the sensor loop is external to a housing coupled to the communication circuitry and energy harvesting circuitry.

4. The system of claim 1, wherein the sensor loop is coupled to a sensor node and also to ground.

5. The system of claim 4, further comprising a first resistor between the energy harvesting circuitry and the sensor node.

6. The system of claim 5, further comprising a second resistor between the ground and the sensor node.

7. The system of claim 4, further comprising a second resistor between the ground and the sensor node.

8. The system of claim 1, further comprising a memory for storing a status of the sensor loop.

9. The system of claim 1, wherein the system is not disabled if the sensor loop is broken.

10. A Radio Frequency Identification (RFID) system, comprising:

communication circuitry for enabling wireless communication with an RF reader;

energy harvesting circuitry for generating an electric current from RF energy;

a sensor loop coupled to the energy harvesting circuitry;

a status register coupled to the sensor loop for indicating a broken or unbroken status of the sensor loop,

wherein the RFID system is passive,

wherein the sensor loop is external to a housing coupled to the communication circuitry and energy harvesting circuitry,

wherein the sensor loop is coupled to a sensor node and also to ground,

a first resistor between the energy harvesting circuitry and the sensor node; and

a second resistor between the ground and the sensor node.

11. The system of claim 10, further comprising a memory for storing a status of the sensor loop.

12. The system of claim 10, wherein the system is not disabled if the sensor loop is broken.

13. A Radio Frequency Identification (RFID) system, comprising:

communication circuitry for enabling wireless communication with an RF reader;

energy harvesting circuitry for generating an electric current from RF energy;

a sensor loop coupled to the energy harvesting circuitry; and

a status register coupled to the sensor loop for indicating a broken or unbroken status of the sensor loop,

wherein the system is not disabled if the sensor loop is broken.

14. The system of claim 13, wherein the RFID system is passive.

15. The system of claim 13, wherein the sensor loop is external to a housing coupled to the communication circuitry and energy harvesting circuitry.

16. The system of claim 13, wherein the sensor loop is coupled to a sensor node and also to ground.

17. The system of claim 16, further comprising a first resistor between the energy harvesting circuitry and the sensor node.

18. The system of claim 17, further comprising a second resistor between the ground and the sensor node.

19. The system of claim 16, further comprising a second resistor between the ground and the sensor node.

20. The system of claim 13, further comprising a memory for storing a status of the sensor loop.

21. A method, comprising:

generating an electric current in a Radio Frequency Identification (RFID) device, the current energizing a sensor loop;

detecting a status of whether the sensor loop is broken or unbroken;

storing the status in at least one of a status register and a nonvolatile memory;

receiving a query from an RFID reader for the status; and

sending the status to the RFID reader.

22. The method of claim 21, wherein the sensor loop is external to a housing coupled to the communication circuitry and energy harvesting circuitry.

23. The method of claim 21, wherein the sensor loop is coupled to a sensor node and also to ground.

24. The method of claim 21, wherein the RFID device is not disabled if the sensor loop is broken.