Radio frequency antenna for a tire and method for same

• US 20040252072A1
• Filed: 03/24/2004
• Published: 12/16/2004
• Est. Priority Date: 06/11/2002
• Status: Active Grant

• Current Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Original Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Adamson, John David, Smith, Cameron Earl, Kelly, Charles Edward, Moreland, Cal
• Granted Patent: US 7,009,576 B2
• Time in Patent Office: Days
• US Class Current: 343/873
• CPC Class Codes: B29D 2030/0077 Directly attaching monitoring devices to tyres before or after vulcanization, e.g. microchips
• CPC Class Codes: B60C 11/00 Tyre tread bands; Tread patterns; Anti-skid inserts
• CPC Class Codes: B60C 13/00 Tyre sidewalls; Protecting, decorating, marking, or the like, thereof B60C17/08 takes precedence; tyre shoulders B60C11/01; removable tyre sidewall trim rings B60B7/01
• CPC Class Codes: B60C 19/00 Tyre parts or constructions not otherwise provided for
• CPC Class Codes: B60C 23/0433 Radio signals
• CPC Class Codes: B60C 23/0493 for attachment on the tyre
• 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 19/07764 the adhering arrangement making the record carrier attachable to a tire tire temperature or pressur control arrangements, see B60C23/00
• CPC Class Codes: H01Q 1/2241 used in or for vehicle tyres
• CPC Class Codes: H01Q 1/32 Adaptation for use in or on road or rail vehicles
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence
• CPC Class Codes: H01Q 9/26 with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength resonant loop antennas H01Q7/00
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00

Abstract

A radio frequency antenna for embedding within a conductive, dielectric material (such as tire rubber) is provided along with a method of embedding a radio frequency antenna in such a material. For very high frequency transmission, improved communication ranges are provided along with improvements in both antenna processing and tuning.

Claims

1. A radio frequency device for integration with conductive, dielectric materials, said device comprising:

a radio component for transmitting radio signals, receiving radio signals, or both;

an antenna connected to said radio component;

an adhesive coating substantially covering at least said antenna; and

,

an insulating layer attached to said antenna by said adhesive coating, said insulating layer being configured to insulate at least said antenna from the conductive, dielectric materials, said insulating layer having a relative dielectic constant less than the relative dielectric constant of the conductive, dielectric materials.

2. A radio frequency device as set forth in claim 1, wherein said insulating layer has a relative dielectric constant about 6 or less at operating frequency.

3. A radio frequency device as set forth in claim 1, wherein said insulating layer is constructed from a silica reinforced elastomer.

4. A radio frequency device as set forth in claim 1, where said insulating layer has an after-cure thickness of at least 0.3 mm.

5. A radio frequency device as set forth in claim 1, wherein said insulating layer provides a dielectric loss of about 0.6 or less at operating frequency.

6. A radio frequency device as set forth in claim 1, wherein said insulating layer has a dielectric loss of about 0.6 or less at operating frequency, a surface resistivity of at least about 10¹² ohms*cm, and a volume resistivity of at least about 10¹³ ohms.

7. A radio frequency device as set forth in claim 1, wherein the conductive, dielectric materials are present within a tire and said insulating layer is configured for being adhered to the tire.

8. A radio frequency device as set forth in claim 1, wherein the conductive, dielectric materials are present within a tire and said insulating layer is configured for being embedded within the tire.

9. A radio frequency device as set forth in claim 1, wherein said radio component operates at a frequency of at least 130 MHz.

10. A tire having a radio frequency device integrated therein, said radio frequency device comprising:

a radio component for transmitting radio signals, receiving radio signals, or both;

an antenna connected to said radio component;

an adhesive coating substantially covering at least said antenna; and

,

an insulating layer attached to said antenna by said adhesive coating, said insulating layer being configured to insulate at least said antenna from said tire, said insulating layer having a relative dielectic constant less than the relative dielectric constant of at least a portion of said tire proximate to said antenna when used with said tire.

11. A tire as set forth in claim 10, wherein said insulating layer has a relative dielectric constant of about 6 or less at the operating frequency of said radio component.

12. A tire as set forth in claim 11, wherein said insulating layer comprises a silica reinforced elastomer.

13. A tire as set forth in claim 12, wherein said insulating layer has an after-cure thickness of at least 0.3 mm.

14. A tire as set forth in claim 13, wherein said insulating layer provides a dielectric loss of of about 0.6 or less at operating frequency.

15. A tire as set forth in claim 13, wherein said insulating layer provides a dielectric loss of of about 0.6 or less at operating frequency, a surface resistivity of at least about 10¹² ohms*cm, and a volume resistivity of at least about 10¹³ ohms.

16. A tire as set forth in claim 13, wherein said radio component operates at a frequency of at least 130 MHz.

17. A method for assembling a radio frequency device for use with a tire, comprising the steps of:

providing a radio component for transmitting radio signals, receiving radio signals, or both;

providing an antenna connected to said radio component;

coating at least said antenna with an adhesive; and

applying an insulating layer to said antenna for attachment by said adhesive coating, said insulating layer being configured to insulate at least said antenna from the tire, said insulating layer having a relative dielectic constant less than the relative dielectric constant of the tire.

18. A method for assembling a radio frequency device for use with a tire as in claim 17, further comprising the step of integrating said insulating layer, antenna, and radio component with the tire.

19. A method for assembling a radio frequency device for use with a tire as in claim 17, further comprising the step of embedding said insulating layer, antenna, and radio component with the tire.

20. A method for assembling a radio frequency device for use with a tire as in claim 17, further comprising the step of attaching said insulating layer to the tire.

21. A method for assembling a radio frequency device for use with a tire as in claim 17, wherein the tire is constructed from elastomeric materials, and further comprising the step of tuning said antenna for the resonant frequency of said elastomeric materials.

22. A method for assembling a radio frequency device for use with a tire as in claim 17, wherein the tire is constructed from elastomeric materials, and further comprising the step of curing said insulating layer with said elastomeric materials.

23. A method for assembling a radio frequency device for use with a tire as in claim 22, wherein said insulating layer has a thickness of at least 0.3 mm after said curing step.

24. A method for assembling a radio frequency device for use with a tire as in claim 17, wherein said insulating layer has a relative dielectric constant of about 6 or less at operating frequency.

25. A method for assembling a radio frequency device for use with a tire as in claim 24, wherein said insulating later is comprised of a silica reinforced elastomer.