Harsh operating environment RFID tag assemblies and methods of manufacturing thereof

• US 8,360,331 B2
• Filed: 05/18/2011
• Issued: 01/29/2013
• Est. Priority Date: 01/29/2010
• Status: Active Grant

• Current Assignee: Innovative Timing Systems LLC
• Original Assignee: Innovative Timing Systems LLC
• Inventors: Hansen, Kurt S.
• Primary Examiner(s): Le, Thien M
• Assistant Examiner(s): JOHNSON, SONJI N
• Application Number:
  US13/110,580
• Publication Number:
  US 20110233283A1
• Time in Patent Office: 622 Days
• Field of Search: 340/572.8, 340/572.7
• US Class Current: 235/492
• CPC Class Codes: G06K 19/07728 the record carrier comprising means for protection against impact or bending, e.g. protective shells or stress-absorbing layers around the integrated circuit
• 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 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: Y10T 29/49018 with other electrical component

Abstract

A radio frequency identification (RFID) tag assembly and method of manufacturing the assembly including an RFID semiconductor chip having an antenna interface mounted on a mounting substrate and having a predetermined operating frequency, a conductor coupled to the antenna interface and formed on the mounting substrate, an antenna electrically coupled to the conductor having a first radiating element lying in a first plane and a second radiating element lying in a second plane that is at an angle relative to the first plane, and an enclosure having a body with a cavity dimensioned for receiving the mounting substrate and RFID semiconductor chip, the conductor, and the first and second radiating elements, the mounting substrate being positioned proximate to the closed end of the cavity and a seal for closing the opening and sealing the cavity.

Claims

1. A radio frequency identification (RFID) tag assembly comprising:

an RFID semiconductor chip having an antenna interface mounted on a mounting surface of a mounting substrate and having a predetermined operating frequency;

a conductor electrically coupled to the antenna interface of the RFID semiconductor chip and formed on the mounting surface of the mounting substrate;

an antenna electrically coupled to the conductor, the antenna including a first radiating element lying in a first plane and a second radiating element lying in a second plane, the second plane being at an angle relative to the first plane; and

an enclosure having a body defining a cavity with a closed end and an opening, the cavity being dimensioned for receiving the mounting substrate with the RFID semiconductor chip, the conductor, and the first and second radiating elements, the mounting substrate being positioned proximate to the closed end of the cavity;

a reflector defining a reflective plane spaced apart from and substantially parallel to the first plane, said reflector being positioned proximate to the opening of the cavity at a spaced apart distance from the first plane with the reflective plane being a distance of about ¼

of a wavelength of the predetermined operating frequency; and

a seal for closing the opening and sealing the cavity.

2. The assembly of claim 1, further comprising a spacer positioned between the first plane and the reflector for maintaining the spaced apart position of the reflector from the first radiating element, wherein the spacer is composed of a material that does not conduct or absorb a substantial amount of energy at the predetermined operating frequency.

3. The assembly of claim 1 wherein the enclosure is configured for mounting to an operating surface with the reflector being positioned between the operating surface and the mounting substrate and the reflective plane being positioned towards the mounting substrate and away from the operating surface.

4. The assembly of claim 1 wherein the reflector is composed of a composite potting compound configured for reflecting energy at the predetermined operating frequency, the potting compound having a dielectric constant responsive to the predetermined operating frequency and providing a capacitive coupling to the antenna, the potting compound further acting as the seal.

5. The assembly of claim 1 wherein the antenna is a bi-planar foil antenna and the first and second radiating elements of the antenna are each foil radiating elements formed on the mounting surface of the mounting substrate, and wherein the mounting substrate includes an angled deformation between the first and second radiating elements defining the angle of the second radiating element relative to the second radiating element.

6. The assembly of claim 1 wherein the first radiating element and the second radiating element are each formed from a common body, the second radiating element extending from an end portion of the first radiating element at a location defined the angle therebetween.

7. The assembly of claim 1 wherein the second radiating element extends from the first plane in a direction towards the reflector and the opening of the cavity.

8. The assembly of claim 1 wherein the antenna is a foil structure defining the first radiating element and the second radiating element.

9. The assembly of claim 6 wherein the antenna has a monolithic body having a first end defining both the first radiating element and the second radiating element.

10. The assembly of claim 1, further comprising a mounting substrate on which the first and second radiating elements are formed, the substrate being deformed at the angle between the first and second radiating elements.

11. The assembly of claim 1 wherein the first radiating element has a length less than about ¼

of a wavelength of the predetermined operating frequency and the second radiating element has a length less than about ¼

of the wavelength of the predetermined operating frequency.

12. The assembly of claim 1 wherein the angle between the second radiating element and an end of the first radiating element is about 90 degrees.

13. The assembly of claim 1 wherein the angle between the second radiating element and an end of the first radiating element is between about 45 degrees and about 135 degrees.

14. The assembly of claim 1 wherein the reflector is the seal.

15. The assembly of claim 1 wherein the antenna is a first antenna component of a bipolar antenna, the bipolar antenna also comprising a second antenna component electrically coupled to the conductor, the second antenna component including a third radiating element lying in the first plane and a fourth radiating element lying in a third plane.

16. A radio frequency identification (RFID) tag assembly comprising:

means for processing received radio frequency identification requests and generating responses to such requests;

means for receiving and transmitting radio frequency energy in a first plane at a predetermined operating frequency between the means for processing and a remote transceiver;

means for receiving and transmitting radio frequency energy in a second plane at a predetermined operating frequency between the means for processing and a remote transceiver, the second plane being at an angle relative to the first plane;

an enclosure having a body defining a cavity with a closed end and an opening, the cavity being dimensioned to receive and enclose the means for processing and means for receiving and transmitting in a first plane and means for receiving and transmitting in a second plane;

means for closing and sealing the cavity of the enclosure including the means for processing and means for receiving and transmitting in a first plane and means for receiving and transmitting in a second plane; and

means for reflecting a portion of the radio frequency energy at the predetermined operating frequency between the remote transceiver and both the means for receiving and transmitting in a first plane and the means for receiving and transmitting in a second plane, said means for reflecting including a reflector defining a reflective plane spaced apart from and substantially parallel to the first plane of the means for receiving and transmitting, said reflector being positioned proximate to the opening of the cavity at a spaced apart distance from the first plane of the means for receiving and transmitting with the reflective plane being a distance of about ¼

of a wavelength of the predetermined operating frequency.

17. A method of manufacturing an RFID tag assembly for use in a harsh operating environment comprising:

structuring an antenna electrically coupled to an RFID semiconductor chip having an antenna interface with a conductor, the RFID semiconductor chip operating at a predetermined operating frequency, said structuring forming the antenna to have a first radiating element lying in a first plane and a second radiating element lying in a second plane at an angle relative to the first plane;

forming an enclosure having a body defining a cavity with a closed end and an opening, the body being formed from a material that does not conduct or absorb a substantial amount of energy at the predetermined operating frequency, the cavity dimensioned for receiving and enclosing the RFID semiconductor chip, conductor and structured antenna positioned proximate to the closed end of the cavity;

mounting the RFID semiconductor chip, conductor and first and second radiating elements of the antenna within the cavity proximate to the closed end of the cavity;

placing a reflector having a substantially planar reflecting plane spaced apart from and substantially parallel to the first plane, the reflector having a body composed of reflecting material configured for reflecting the predetermined operating frequency, the reflector being mounted proximate to the opening to the cavity;

the reflector defining a reflective plane spaced apart from and substantially parallel to the first plane containing the first radiating element, said reflector being positioned proximate to the opening of the cavity at a spaced apart distance from the first plane containing the first radiating element with the reflective plane being a distance of about ¼

of a wavelength of the predetermined operating frequency; and

closing the opening of the cavity containing the RFID semiconductor chip, conductor, reflector and antenna, said closing including sealing the opening.

18. The method of claim 17 wherein the first radiating element is formed to have a length less than about ¼

of a wavelength of the predetermined operating frequency and the second radiating element is formed to have a length less than about ¼

of the wavelength of the predetermined operating frequency.

19. The method of claim 17 wherein the second radiating element is formed to have the angle relative to the first plane of about 90 degrees.

20. The method of claim 17 wherein the second radiating element is formed to have the angle relative to the first plane of between about 45 degrees and about 135 degrees.

21. The method of claim 17 wherein the second radiating element is formed to extend from the first plane in the direction of the opening of the cavity.

22. The method of claim 17 wherein the second radiating element is formed to extend from the first plane in the direction of the opening of the cavity and the reflector.

23. The method of claim 17 wherein the body of the reflector is composed of a composite material and wherein placing the reflector includes closing the opening of the cavity.

24. The method of claim 17, further comprising inserting a spacer between the first plane and the reflector for maintaining the spaced apart position of the reflector from the first radiating element.

25. The method of claim 24 wherein the spacer is composed of a material that does not conduct or absorb a substantial amount of energy at the predetermined operating frequency.

26. The method of claim 17 wherein placing the reflector includes forming the body of the reflector to define the reflective plane from a composite material having a dielectric constant responsive to the predetermined operating frequency.

27. The method of claim 26 wherein forming the body of the reflector includes mixing in a predetermined amount of a reflective substance into the composite material.

28. The method of claim 17 wherein structuring the antenna includes structuring the first and second radiating elements as foil structures.

29. The method of claim 17 wherein structuring the antenna includes modifying an RFID tag assembly formed on a mounting substrate having the RFID semiconductor chip, conductor and a preformed planar foil antenna formed thereon, the preformed antenna lying in the first plane and having a length equal to or greater than about ½

of a wavelength of the predetermined operating frequency, wherein structuring the antenna includes cutting an end portion of the mounting surface and the preformed antenna formed thereon to form a reduced length antenna having a length of the antenna to less than about ½

of the wavelength of the predetermined operating frequency and deforming an end of the reduced length antenna at the angle to form an angled deformation between the second radiating element defined at the end of the antenna and the first radiating element being a portion of the reduced length antenna that is not deformed, the first and second radiating elements each having a length of less than about ¼

of the wavelength of the predetermined operating frequency.

30. The method of claim 29 wherein the angle of the deformation is about 90 degrees.

31. The method of claim 29 wherein the angle of the deformation is between about 45 degrees and about 135 degrees.

32. The method of claim 17 wherein the RFID tag assembly has a bipolar antenna having a first component and an opposing second component,

wherein structuring the antenna includes modifying an RFID tag assembly formed on a mounting substrate having the RFID semiconductor chip, conductor and a preformed planar foil bipolar antenna formed at opposing ends of the mounting substrate, the two components of the preformed bipolar antenna lying in the first plane and each component having a length equal to or greater than about ½

of a wavelength of the predetermined operating frequency, wherein structuring the antenna includes cutting a portion of each of the opposing ends of the mounting substrate to form cut ends of two reduced length antenna components each having a length less than about ½

of the wavelength of the predetermined operating frequency, and deforming each cut end of each reduced length antenna components at the angle to form two angled deformations defining the angle between each second radiating element component defined at each cut end of the reduced length antenna component and each first radiating element as formed as a portion of the reduced length antenna that is not deformed, each of the first and second radiating elements having a length of less than about ¼

of the wavelength of the predetermined operating frequency.