THREE DIMENSIONAL RF SIGNATURES

• US 20130088355A1
• Filed: 11/13/2012
• Published: 04/11/2013
• Est. Priority Date: 09/22/2006
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Ashwood-Smith, Peter, Montuno, Delfin Y., Dasylva, Abel
• Granted Patent: US 9,013,308 B2
• Time in Patent Office: Days
• US Class Current: 340/572.1
• CPC Class Codes: G01S 13/758 using a signal generator powered by the interrogation signal
• CPC Class Codes: G01S 5/0247 Determining attitude
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/07767 the first and second communication means being two different antennas types, e.g. dipole and coil type, or two antennas of the same kind but operating at different frequencies
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G08B 13/2428 Tag details

Abstract

Method and systems to detect tampering in a physical article are described herein. A method includes receiving, at a first point in time, at least two response signals from at least one RF tag in a set of RF tags associated with the physical article; forming a first response signature for the physical article based on the received response signals; receiving a second response signal from at least one other RF tag in the set of RF tags associated with the physical article at a second point in time; assessing a relative spacing between the RF tags associated with the physical article has changed from the first point in time to the second point in time; and determining tampering of the physical article as a result of the spacing assessment.

Claims

1-22. -22. (canceled)

23. A method of detecting tampering of a physical article, the method comprising:

receiving, at a first point in time, at least two response signals from at least one RF tag in a set of RF tags associated with the physical article

forming a first response signature for the physical article based on the received response signals;

receiving a second response signal from at least one other RF tag in the set of RF tags associated with the physical article at a second point in time;

assessing a relative spacing between the RF tags associated with the physical article has changed from the first point in time to the second point in time; and

determining tampering of the physical article as a result of the spacing assessment.

24. The method of claim 23, wherein at least one RF tag comprises:

at least two non-coplanar power coils; and

a circuit connected to the non-coplanar power coils, the circuit configured to detect at least one electrical characteristic from at least two of the non-coplanar power coils, and to transmit a RF tag code and an indication of the detected electrical characteristics to a RF tag reader.

25. The method of claim 24, wherein the electrical characteristic is at least one of power, current, and voltage.

26. The method of claim 24, wherein the electrical characteristic is the same for each of the at least two non-coplanar power coils.

27. The method of claim 24, wherein the at least two non-coplanar power coils comprise at least three non-coplanar power coils, at least three of which are formed on orthogonal planes.

28. The method of claim 24, wherein power from each of the non-coplanar power coils is used to provide power to the circuit.

29. The method of claim 24, wherein at least one of the RF tags is a passive RF tag.

30. The method of claim 23, wherein the first response signature comprises a three dimensional RF signature, and wherein the method comprises determining an orientation of the physical article based on the three dimensional RF signature.

31. The method of claim 23, further comprising directing electromagnetic radiation toward the physical article.

32. The method of claim 23, wherein the first response signature depends on the orientation of the RF tags relative to a directed electromagnetic radiation.

33. The method of claim 23, wherein the first response signature depends on the placement of the RF tags on the article.

34. The method of claim 23, wherein the first response signature depends on the path of motion of the article.

35. A RF tag system, comprising:

at least two RF tags, at least one of the RF tags comprising at least two non-coplanar power coils; and

a circuit connected to the non-coplanar power coils, the circuit configured to detect at least one electrical characteristic from at least two of the non-coplanar power coils;

a RF tag reader configured to;

receive a RF tag code and an indication of the detected electrical characteristics from the circuit; and

determine tampering of the physical article based on the received RF tag code and at least one detected electrical characteristic.

36. The system of claim 35, wherein the electrical characteristic is at least one of power, current, and voltage.

37. The system of claim 35, wherein the electrical characteristic is the same for at least two non-coplanar power coils.

38. The system of claim 35, wherein the at least two non-coplanar power coils comprise at least three non-coplanar power coils, at least three of which are formed on orthogonal planes.

39. The system of claim 35, wherein power from at least one of the non-coplanar power coils is used to provide power to the circuit.

40. The system of claim 35, wherein at least one of the RF tags is a passive RF tag.

41. The system of claim 35, wherein all of the RF tags are passive RF tags.

42. The system of claim 35, wherein the RF reader is configured to determine a three-dimensional response signature for the physical article based on at least two response signals from at least one of the RF tags.