Radio frequency data communications device

• US 7,385,477 B2
• Filed: 11/29/2005
• Issued: 06/10/2008
• Est. Priority Date: 05/13/1996
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Keystone Technology Solutions, LLC
• Inventors: Rotzoll, Robert R., Lowrey, Tyler F., Ovard, David K., Tuttle, John R., Tuttle, Mark E., Higgins, Brian P., Yu, Shu-Sun, O'Toole, James E., Devereaux, Kevin M., Pax, George E.
• Primary Examiner(s): Holloway, III; Edwin C
• Application Number:
  US11/290,238
• Publication Number:
  US 20060082445A1
• Time in Patent Office: 924 Days
• Field of Search: 370/310, 370/311, 340/10.4, 340/10.33, 340/10.1, 340/10.5, 340/10.51, 340/10.34, 340/572.1, 340/825.56, 340/10.2, 340/572.8, 342/42, 342/44, 342/51, 375/130, 455/343.2, 455/343.4
• US Class Current: 340/10.2
• CPC Class Codes: G06K 19/0707 the arrangement being capable of collecting energy from external energy sources, e.g. thermocouples, vibration, electromagnetic radiation G06K19/0702 takes precedence
• CPC Class Codes: G06K 19/0712 the arrangement being capable of triggering distinct operating modes or functions dependent on the strength of an energy or interrogation field in the proximity of the record carrier active means for hindering electromagnetic reading or writing G06K19/07336
• 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 19/0723 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 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• 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 19/07758 arrangements for adhering the record carrier to further objects or living beings, functioning as an identification tag
• 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
• CPC Class Codes: G06K 7/10059 transponder driven
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H03L 7/0995 the oscillator comprising a ring oscillator
• CPC Class Codes: H03L 7/148 said digital means comprising a counter or a divider

Abstract

A radio frequency identification device includes an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Claims

1. A radio frequency identification system comprising:

a host computer including an application program to control an interrogator and to receive data from the interrogator;

a plurality of interrogators, including the interrogator coupled to the host computer and configured to transmit a forward link signal to implement an arbitration scheme to determine an identification code of an RFID tag from among a plurality of RFID tags contained within an RF field of the interrogator, the forward link signal comprising an RF carrier that is modulated using amplitude shift keying to provide a first parameter, a second parameter, a third parameter, a CRC, and return link configuration information;

an item of inventory having affixed thereto a label comprising identifying text; and

the RFID tag disposed on plastic substrate and laminated to a back side of the label to track the item via the host computer, the tag comprising a dipole antenna and no more than one monolithic integrated circuit storing an identification code associated with the item and configured to switch between a plurality of available modulation schemes, the tag configured to receive the signal via the dipole antenna, to store the first parameter, to compare the second parameter to a value stored in the integrated circuit other than the identification code, to generate a random number, to compare the third parameter to the first parameter, and to communicate a reply to the signal via the dipole antenna depending, at least in part, on whether the third parameter matches the first parameter and whether the second parameter matches the value, the reply comprising a return link signal modulated in accordance with a modulation scheme selected by the return link configuration information, wherein in accordance with one of the plurality of modulation schemes each bit of the return link signal is multiplied by a selectable one of at least three subcarrier sequences selected by the return link configuration information.

2. The system of claim 1, wherein the RF carrier operates in a frequency range that includes 915 MHz.

3. The system of claim 1, wherein the forward link signal further provides a preamble comprising at least one data bit-0 and excluding any data bit-1'"'"'s.

4. The system of claim 1, wherein the interrogator and the tag are configured to operate in accordance with frequency hopping spread spectrum.

5. The system of claim 1, wherein the reply comprises a preamble comprising a plurality of data bit-0'"'"'s and a plurality of data bit-1'"'"'s.

6. The system of claim 1, wherein the tag stores the identification code in a first region of memory, and the tag further comprises a second region of memory dedicated to user memory for read/write data storage.

7. The system of claim 6, wherein the tag further stores a tag revision number in a third region of memory.

8. The system of claim 7, wherein the tag further stores a tag identifier to indicate tag manufacture information.

9. The system of claim 1, wherein the tag further comprises a counter configured to prevent the tag from communicating the reply if the counter is greater than zero.

10. The system of claim 1, wherein the forward link signal further comprises a kill command to disable the tag and to prevent the tag from communicating replies.

11. The system of claim 1, wherein the reply includes at least a portion of the identification code.

12. The system of claim 11, wherein the reply further includes a parameter that describes how many bytes are included in at least a portion of the reply.

13. The system of claim 1, wherein the reply includes the random number.

14. The system of claim 13, wherein the value is the random number.

15. The system of claim 1, wherein the forward link signal further provides a parameter that describes a length of at least a portion of the forward link signal.

16. The system of claim 1, wherein the first parameter is equal to the third parameter, and the first and third parameters are configured to distinguish the interrogator from one or more other potential interrogators within communication range of the tag.

17. The system of claim 1, wherein the reply includes a CRC.

18. A system for tracking items, comprising:

an interrogator configured to transmit an interrogation signal to implement a collision arbitration scheme to determine a respective identification code of each respective RFID tag of plurality of RFID tags disposed within an RF field of the interrogator, the interrogation signal comprising a first parameter, a second parameter, a third parameter, and return link configuration information;

an item to be tracked; and

a label affixed to the item, the label comprising visual information on its front side and an RFID tag attached to its back side, the tag comprising an antenna disposed on a plastic sheet and an integrated circuit storing an identification code associated with the item, wherein the tag is configured to receive the interrogation signal via the antenna, to store the first parameter, to compare the second parameter to a value stored in the integrated circuit other than the identification code, to generate a random number identifying the tag, to compare the third parameter to the first parameter, and to communicate a reply signal to the interrogation signal via the antenna it in part, the third parameter matches the first parameter and the second parameter matches the value, wherein the reply signal is configured to be modulated using a selected one of a plurality of modulation types as set by the return link configuration information, and, in accordance with one of the plurality of modulation types, a baseband waveform is configured to be multiplied by a selected one of three different pulse waveforms as set by the retum link configuration information; and

a host computer coupled to the interrogator to receive and process the identification code.

19. The system of claim 18, wherein the interrogator is configured to operate in accordance with frequency hopping spread spectrum in a frequency range that includes 915 MHz.

20. The system of claim 18, wherein the interrogation signal further comprises a preamble comprising at least one data bit-0 and excluding any data bit-1'"'"'s. and wherein the reply signal comprises a preamble comprising a plurality of data bit-0'"'"'s and a plurality of data bit-1'"'"'s.

21. The system of claim 18, wherein the tag stores the identification code in a first region of memory, and the tag further comprises a second region of memory dedicated to user memory for read/write data storage.

22. The system of claim 21, wherein the tag further stores a tag identifier to indicate tag manufacture information.

23. The system of claim 22, wherein the tag further stores a tag revision number in a third region of memory.

24. The system of claim 18, wherein the tag further comprises a counter configured to be decremented and to prevent the tag from communicating the reply signal if the counter is greater than zero.

25. The system of claim 18, wherein the interrogation signal further comprises a kill command to disable a transmitter of the tag while leaving the receiver functional.

26. The system of claim 18, wherein the reply signal includes a parameter to indicate how many bytes are included in at least a portion of the reply signal.

27. The system of claim 26, wherein the reply signal includes at least a portion of the identification code.

28. The system of claim 18, wherein the reply signal includes the random number.

29. The system of claim 28, wherein the value is the random number.

30. The system of claim 18, wherein the first and third parameters are configured to distinguish the interrogator from another interrogator within communication range of the tag.

31. The system of claim 18, wherein the visual information includes text.

32. An RFID system, comprising:

a first interrogator configured to transmit a first interrogation signal to perform collision arbitration, the first interrogation signal comprising a first parameter, a second parameter, a third parameter that is equal to the first parameter, and return link configuration information;

a second interrogator configured to transmit a second interrogation signal to perform collision arbitration;

a plurality of items to be managed, each respective item of the plurality of items having affixed thereto a respective label, each respective label having a respective front side and a respective back side; and

a plurality of RFID tags, each respective RFID tag of the plurality of RFID tags affixed to the back side of a respective label, each respective RFID tag comprising a respective antenna disposed on a respective plastic substrate and a respective integrated circuit storing a respective identification code associated with a respective item, wherein each respective tag is configured to receive the interrogation signal, to compare the second parameter to a value stored in the respective integrated circuit other man the respective identification code, to independently generate a respective random number identifying the respective tag, to compare the third parameter to the first parameter to distinguish the first interrogator from the second interrogator, and to communicate a respective reply signal to the first interrogator if, at least in part, the third parameter matches the first parameter and the second parameter matches the respective value, wherein the respective reply signal is configured to be modulated using one of a plurality of modulation types selected by the first interrogator, and wherein in accordance with the one of the plurality of modulation types, a bit is configured to be represented by a selected one of three different waveform sequence lengths selected by the first interrogator.

33. The system of claim 32, wherein the first and second interrogators are configured to operate in accordance with frequency hopping spread spectrum in a frequency range that includes 915 MHz.

34. The system of claim 33, wherein the first and second interrogation signals further comprise a preamble comprising at least one data bit-0 and excluding any data bit-1'"'"'s, and wherein each respective reply signal comprises a preamble comprising a plurality of data bit-0'"'"'s and a plurality of data bit-1'"'"'s.

35. The system of claim 32, wherein each respective RFID tag stores the respective identification code in a respective first region of memory, stores respective tag revision information in a respective second region of memory, stores a respective tag identifier to indicate tag manufacture information, and comprises a respective region of dedicated user memory for read/write data storage.

36. The system of claim 32, wherein each respective tag further comprises a respective counter configured to be decremented and to prevent the respective tag from communicating the respective reply signal while the respective counter is greater than zero.

37. The system of claim 32, wherein the first interrogation signal further comprises a kill command to disable a tag.

38. The system of claim 32, wherein the respective reply signal includes the respective random number.

39. The system of claim 32, wherein the respective value is the respective random number.

40. The system of claim 32, wherein the respective front side of each respective label comprises visual information including text.

41. A system, comprising:

a first interrogator configured to transmit a first interrogation signal to implement collision arbitration;

a second interrogator configured to transmit a second interrogation signal to implement collision arbitration, the second interrogation signal comprising a first parameter, a second parameter, a third parameter equal to the first parameter for use in distinguishing the second interrogation signal from the first interrogation signal, and return link configuration information;

a host computer coupled to the first and second interrogators,

a plurality of items to be monitored via the host computer;

a plurality of labels, each respective label affixed to a respective item and comprising visual information including text formed a respective front side; and

an RFID tag attached to a back side of at least one of the labels attached to an item, the tag comprising an antenna disposed on a plastic substrate and an integrated circuit storing an identification code associated with the item, wherein the tag is configured to store a value other than the identification code, to generate a random number identifying the tag, and to communicate a reply signal to the second interrogation signal if, at least in part, the tag determines that the second parameter matches the value and the third parameter matches the first parameter, and wherein the tag is further configured to modulate the reply signal using a selectable one of a plurality of modulation types as set by the return link configuration information, and wherein in accordance with one of the plurality of modulation types, a bit is configured to be represented by a selectable one of at least three different waveform sequences, each of different lengths, as set by the return link configuration information.

42. The system of claim 41, wherein the second interrogator is configured to operate in accordance with frequency hopping spread spectrum in a frequency range that includes 915 MHz.

43. The system of claim 41, wherein the second interrogation signal further comprises a preamble comprising at least one data bit-0 and excluding any data bit-1'"'"'s, and wherein the reply signal comprises aprearnble comprising a plurality of data bit-0'"'"'s and a plurality of data bit-1'"'"'s.

44. The system of claim 41, wherein the tag stores the identification code in a first region of memory, a tag revision number in a second region of memory, a tag identifier to indicate tag manufacture information, and the tag further comprises a third region of memory dedicated to user memory for read/write data storage.

45. The system of claim 41, wherein the tag further comprises a counter configured to be decremented and to prevent the tag from communicating the reply signal if the counter is greater than zero.

46. The system of claim 45, wherein the tag is further configured to be disabled in response to a kill command transmitted by the second interrogator.

47. The system of claim 46, wherein the tag is further configured to include a parameter in the reply signal to indicate how many bytes are included in at least a portion of the reply signal.

48. The system of claim 41, wherein the tag is further configured to include at least a portion of the identification code in the reply signal.

49. The system of claim 41, wherein the tag is further configured to include the random number in the reply signal.

50. The system of claim 49, wherein the value is the random number.

51. The system of claim 41, wherein a length of a first of the waveform sequences is at least twice as long as a length of a second of the waveform sequences, and a length of the second of the waveform sequences is at least twice as long as a length of a third of the waveform sequences.