RFID tag with modifiable and reversible read range

• US 20060145851A1
• Filed: 12/17/2004
• Published: 07/06/2006
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Posamentier, Joshua
• Granted Patent: US 7,327,257 B2
• Time in Patent Office: Days
• US Class Current: 340/572.100
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer

Abstract

According to some embodiments, read range control update information is received in a radio frequency (RF) signal. The information is used to control a read range of an antenna. The read range of the antenna can be increased or deceased, for example, by changing an impedance of the antenna.

Claims

1. A system comprising:

an antenna; and

a read range control circuitry coupled to the antenna;

the read range control circuitry to modify a read range of the antenna between a first read range and a second read range.

2. The system as recited in claim 1, the read range control circuitry to modify the read range of the antenna according to a radio frequency (RF) signal received on the antenna.

3. The system as recited in claim 1, the read range control circuitry comprising an impedance control unit to modify the read range of the antenna between the first read range and the second read range.

4. The system as recited in claim 3, the impedance control unit comprising an impedance mismatch tap.

5. The system as recited in claim 1, the read range control circuitry wherein the first read range is greater than the second read range.

6. The system as recited in claim 1, the read range control circuitry to modify the read range between three or more read range distances.

7. The system as recited in claim 1, further comprising a radio frequency identification (RFID) tag coupled to the antenna.

8. The system as recited in claim 1, further comprising non-volatile memory to store read range information received on the antenna.

9. The system as recited in claim 1, further comprising power harvesting circuitry coupled to the antenna to harvest power from a radio frequency (RF) signal containing read range update information.

10. The system as recited in claim 1, further comprising a modulating switch coupled to the antenna to send a read range update acknowledgement message on the antenna.

11. A method comprising:

receiving a radio frequency (RF) signal containing read range update information; and

updating a read range capability of an antenna according to the read range update information;

wherein the read range update information specifies one of two or more pre-specified read ranges.

12. The method as recited in claim 11, wherein the two or more pre-specified read ranges comprise a short read range and a long read range.

13. The method as recited in claim 11, wherein updating the read range capability comprises modifying an impedance of the antenna.

14. The method as recited in claim 11, further comprising storing the read range update information in non-volatile memory.

15. The method as recited in claim 11, further comprising authenticating the RF signal.

16. The method as recited in claim 11, further comprising decrypting the RF signal.

17. The method as recited in claim 11, further comprising sending a read range update acknowledgement message.

30. The method as recited in claim 11, further comprising receiving a read range update acknowledgement message.

18. An apparatus comprising:

a read range control circuitry to modify a read range of the antenna between a first read range and a second read range.

19. The apparatus as recited in claim 18, the read range control circuitry to modify the read range of the antenna according to a radio frequency (RF) signal received on the antenna.

20. The apparatus as recited in claim 18, the read range control circuitry comprising an impedance control unit to modify the read range of the antenna.

21. The apparatus as recited in claim 20, the impedance control unit comprising an impedance mismatch tap.

22. The apparatus as recited in claim 18, further comprising a radio frequency identification (RFID) tag coupled to the read range control circuitry.

23. The apparatus as recited in claim 18, further comprising non-volatile memory to store read range information received on the antenna.

24. The apparatus as recited in claim 18, further comprising power harvesting circuitry coupled to the antenna to harvest power from a radio frequency (RF) signal containing read range update information.

25. The apparatus as recited in claim 18, further comprising a modulating switch coupled to the read range control circuitry to send a read range update acknowledgement message on the antenna.

26. A method comprising:

sending a radio frequency (RF) signal containing read range update information;

wherein the read range update information specifies one of two or more pre-specified read ranges.

27. The method as recited in claim 26, wherein the two or more pre-specified read ranges comprise a short read range and a long read range.

28. The method as recited in claim 26, wherein the RF signal further contains an authentication.

29. The method as recited in claim 26, wherein the RF signal is encrypted.