Radio frequency identification inlay with improved readability

• US 8,098,161 B2
• Filed: 12/01/2008
• Issued: 01/17/2012
• Est. Priority Date: 12/01/2008
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Lavedas, Thomas G.
• Primary Examiner(s): Lee, Benjamin C
• Assistant Examiner(s): MEHRAVARI, PETER CYRUS
• Application Number:
  US12/325,413
• Publication Number:
  US 20100134291A1
• Time in Patent Office: 1,142 Days
• Field of Search: 340/572.7, 340/572.8, 340/568.7, 340/572.5, 340/10.1, 343/842, 343/843, 343/844, 343/846, 343/893
• US Class Current: 340/572.7
• 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: 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: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 19/30 the primary active element being centre-fed and substantially straight, e.g. Yagi antenna
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

A radio-frequency identification (RFID) inlay is provided that is substantially isolated from the environment in proximity to one side of the device. A radio-frequency identification (RFID) inlay is provided including a two-port microchip having a first and a second port, a first antenna coupled to the first port of the two-port microchip, a ground-plane, a first high-impedance body disposed substantially parallel to the first antenna and between the first antenna and the ground-plane, the first high-impedance body insulated from the ground-plane. The RFID inlay further includes a second antenna coupled to the second port of the two-port microchip, and a second high-impedance body disposed substantially parallel to the second antenna and between the second antenna and the ground-plane, the second high-impedance body insulated from the ground-plane.

Claims

1. A radio-frequency identification (RFID) inlay comprising:

a microchip;

an antenna coupled to a port of the microchip;

a ground-plane disposed substantially parallel to the antenna;

a high-impedance body disposed substantially parallel to the antenna and between the antenna and the ground-plane; and

a continuous insulating layer disposed between the ground-plane and the high-impedance body to electrically insulate the high-impedance body from the ground-plane.

2. The RFID inlay of claim 1, further comprising a laminate material disposed over an outer surface of the RFID inlay.

3. The RFID inlay of claim 2, wherein the RFID inlay is an RFID card and the laminate material comprises a plastic material.

4. The RFID card of claim 3, wherein the distance between the antenna and the ground-plane is one one-hundredth of the operational wavelength of the RFID inlay.

5. The RFID card of claim 3 having a thickness less than or equal to 0.76 millimeters.

6. The RFID card of claim 3 having a width less than or equal to 86 millimeters and a length less than or equal to 54 millimeters.

7. The RFID card of claim 3 having a rectangular or a circular shape.

8. The RFID inlay of claim 2, wherein the RFID inlay is an RFID tag and the laminate material comprises a paper material.

9. The RFID tag of claim 8, wherein the distance between the antenna and the ground-plane is one one-hundredth of the operational wavelength of the RFID inlay.

10. The RFID tag of claim 8 having a width less than or equal to 86 millimeters and a length less than or equal to 54 millimeters.

11. The RFID tag of claim 8 having a rectangular or a circular shape.

12. The RFID inlay claim 1, wherein the high-impedance body comprises:

a capacitor and an inductor to produce a resonance at the operational frequency of the RFID inlay.

13. The RFID inlay of claim 1, wherein the antenna is one of a C-shaped, or Z-shaped antenna.

29. The RFID inlay of claim 1, wherein the high-impedance body comprises:

a plurality of conductive lands coupled by a plurality of conductive strips, the conductive lands coplanar to the conductive strips.

30. The RFID inlay of claim 29, wherein the conductive lands and the conductive strips are segregated into at least six similarly patterned portions.

33. The RFID inlay of claim 1, wherein the insulating layer is a first insulating layer, further comprising:

a second insulating layer disposed between the antenna and the high-impendence body to electrically insulate the high-impedance body from the antenna, the first and second insulating layers forming an insulating body about the antenna and the high-impedance body and the ground-plane.

34. The RFID inlay of claim 29, wherein the high-impedance body provides a resonance at the operational frequency of the RFID inlay, wherein the resonance is a function of an area of at least one of the conductive lands and a length of at least one of the conductive strips.

14. A radio-frequency identification (RFID) inlay comprising:

a two-port microchip having a first and a second port;

a first antenna coupled to the first port of the two-port microchip;

a ground-plane;

a first high-impedance body disposed substantially parallel to the first antenna and between the first antenna and the ground-plane;

a second antenna coupled to the second port of the two-port microchip;

a second high-impedance body disposed substantially parallel to the second antenna and between the second antenna and the ground-plane, and;

a continuous insulating layer disposed between the ground-plane and the first high-impedance body to electrically insulate the first high-impedance body from the ground-plane.

15. The RFID inlay of claim 14, further comprising a laminate material disposed over an outer surface.

16. The RFID inlay of claim 15, wherein the RFID inlay is an RFID card and the laminate material comprises a plastic material.

17. The RFID card of claim 16, wherein the distance between each of the antennas and the ground-plane is one one-hundredth of the operational wavelength of the RFID inlay.

18. The RFID card of claim 17 having a thickness is less than or equal to 0.76 millimeters.

19. The RFID card of claim 16 having a width less than or equal to 86 millimeters and a length less than or equal to 54 millimeters.

20. The RFID card of claim 16 having a rectangular or a circular shape.

21. The RFID inlay of claim 15, wherein the RFID inlay is a RFID tag and the laminate material comprises a paper material.

22. The RFID tag of claim 21, wherein the distance between each of the antennas and the ground-plane is one one-hundredth of the operational wavelength of the RFID inlay.

23. The RFID tag of claim 21 having a width less than or equal to 86 millimeters and a length less than or equal to 54 millimeters.

24. The RFID tag of claim 21 having a rectangular or a circular shape.

25. The RFID tag of claim 14, wherein each of the high-impedance bodies comprises:

a capacitor and an inductor to produce a resonance at the operational frequency of the RFID inlay.

26. The RFID tag of claim 14, wherein each of the antennas is one of a C-shaped or Z-shaped antenna.

27. The RFID tag of claim 14, wherein the first and second antennas form an X-shape configuration centered about the two-port microchip.

28. The RFID tag of claim 14, wherein the first antenna further comprises:

a first T-shaped element; and

a second T-shaped element coupled to the first T-shaped element at the two-port microchip,

and the second antenna further comprises;

a third T-shaped element; and

a fourth T-shaped element coupled to the third T-shaped element at the two-port microchip,

wherein the second antenna is rotated 90 degrees with respect to the first antenna about the two-port microchip.

31. The RFID inlay of claim 14, wherein at least one of the first high-impedance body or the second high-impedance body comprises:

a plurality of conductive lands coupled by a plurality of conductive strips, the conductive lands coplanar to the conductive strips.

32. The RFID inlay of claim 31, wherein the conductive lands and the conductive strips are segregated into at least six similarly patterned portions.

35. The RFID inlay of claim 31, wherein the plurality of conductive lands and the plurality of conductive strips provide a resonance at the operational frequency of the RFID inlay, wherein the resonance is a function of an area of at least one of the conductive lands and a length of at least one of the conductive strips.

36. The RFID inlay of claim 14, wherein the insulating layer is a first insulating layer, further comprising:

a second insulating layer disposed between the first antenna and the first high-impendence body to electrically insulate the first high-impedance body from the first antenna, the first and second insulating layers forming an insulating body about the first antenna and the first high-impedance body and the ground-plane.