Methods of tagging an object having a conductive surface

• US 6,278,369 B2
• Filed: 12/18/2000
• Issued: 08/21/2001
• Est. Priority Date: 09/02/1999
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Khatri, Dirgha, Smith, Freddie W.
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US09/740,612
• Publication Number:
  US 20010000430A1
• Time in Patent Office: 246 Days
• Field of Search: 340/572.7, 340/10.42, 343/700.MS, 298/46, 342/51
• US Class Current: 340/572.7
• CPC Class Codes: G01S 13/751 wherein the responder or reflector radiates a coded signal
• 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 19/07749 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 19/07786 the antenna being of the HF type, such as a dipole
• 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: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: G08B 13/2431 Tag circuit details
• CPC Class Codes: G08B 13/2485 Simultaneous detection of multiple EAS tags
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• 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 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence

Abstract

A transponder module includes a circuit board having top and bottom surfaces and an inverted-F receive antenna formed on the circuit board. The receive antenna includes a ground plane formed on one of the surfaces and an active element formed above the ground plane. The module also includes a RF engine having an input coupled to the receive antenna, an output and a power supply input. The module additionally includes a RF decoupling network having first and second ports. The first port is coupled to the output of the RF engine. The module further includes an inverted-F backscatter antenna coupled to the second port of the RF decoupling network. The backscatter antenna includes a second ground plane formed on one of the surfaces and a second active element formed above the second ground plane. A method of tagging an object having a conductive surface includes coupling a transponder module including a low profile antenna to the conductive surface such that a ground plane contained in the transponder module is adjacent the conductive surface of the object and transmitting a signal from the low profile antenna to an interrogator, the signal including information relevant to the object.

Claims

1. A method of tagging an object having a conductive surface comprising:

coupling a transponder module including a low profile antenna to the conductive surface such that a ground plane contained in the transponder module is adjacent the conductive surface of the object; and

transmitting a signal from the low profile antenna to an interrogator, the signal including information relevant to the object, wherein transmitting a signal comprises transmitting a signal from an inverted-F antenna in response to receipt of an interrogation signal from the interrogator.

2. A method of tagging an object having a conductive surface comprising:

coupling a transponder module including a low profile antenna to the conductive surface such that a ground plane contained in the transponder module is adjacent the conductive surface of the object;

transmitting a signal from the low profile antenna to an interrogator, the signal including information relevant to the object;

receiving an interrogation signal by a low profile antenna contained in the transponder module; and

wherein transmitting a signal comprises transmitting a signal including information relevant to the object from a low-profile backscatter antenna contained in the module.

3. A method of tagging an object having a conductive surface comprising:

coupling a transponder module to the conductive surface such that a ground plane contained in the transponder module is adjacent the conductive surface of the object;

receiving an interrogation signal in a low profile receive antenna contained in the module; and

transmitting a backscatter signal from a low profile backscatter antenna to an interrogator in response to the interrogation signal, the backscatter signal including information relevant to the object.

4. The method of claim 3, wherein receiving an interrogation signal comprises receiving an interrogation signal by an inverted-F receive antenna.

5. The method of claim 3, wherein transmitting a backscatter signal comprises transmitting a backscatter signal from an inverted-F backscatter antenna.

6. The method of claim 3, wherein coupling the transponder module includes coupling a transponder module including:

a circuit board having first and second surfaces;

a ground plane formed on the first surface;

a low profile receive antenna formed on the circuit board over the ground plane;

a RF engine having an input coupled to the receive antenna, an output and a power supply input;

a RF decoupling network having first and second ports, the first port coupled to the output of the RF engine;

a second ground plane formed on the first surface; and

a low profile backscatter antenna coupled to the second port of the RF decoupling network, the backscatter antenna formed over the second ground plane, and wherein the ground plane contained in the transponder module adjacent the conductive surface includes the second ground plane.

7. The method of claim 6, further comprising coupling a button-type battery to the transponder module, the button-type battery having a first electrode coupled to the ground plane and a second electrode coupled to the power supply input to the RF engine.

8. The method of claim 6, wherein the RF engine comprises a small outline integrated circuit.

9. The method of claim 3, further comprising

receiving an interrogation signal by an inverted-F receive antenna contained in the transponder module;

and

wherein transmitting a signal comprises transmitting a signal including information relevant to the object from an inverted-F backscatter antenna contained in the module.

10. The method of claim 3, further comprising receiving an interrogation signal by a receive antenna including an active element that is one-fourth of a wavelength in length.

11. The method of claim 3, wherein transmitting a signal comprises transmitting a signal including information relevant to the object from a backscatter antenna including an active element that is less than one-fourth of a wavelength in length.

12. The method of claim 3, further comprising receiving an interrogation signal by a receive antenna including an active element that is one-fourth of a wavelength in length;

and wherein transmitting a signal comprises transmitting a signal including information relevant to the object from a backscatter antenna including an active element that is less than one-fourth of a wavelength in length.

13. A method of tagging an object having a conductive surface comprising:

coupling a transponder module including a low profile antenna to the conductive surface such that a ground plane contained in the transponder module is adjacent the conductive surface of the object; and

transmitting a signal from the low profile antenna to an interrogator, the signal including information relevant to the object, wherein coupling the transponder module includes coupling a transponder module including;

a circuit board having first and second surfaces;

a ground plane formed on the first surface;

a low profile receive antenna formed on the circuit board over the ground plane;

a RF engine having an input coupled to the receive antenna, an output and a power supply input;

a RF decoupling network having first and second ports, the first port coupled to the output of the RF engine;

a second ground plane formed on the first surface; and

a low profile backscatter antenna coupled to the second port of the RF decoupling network, the backscatter antenna formed over the second ground plane, and wherein the ground plane contained in the transponder module adjacent the conductive surface includes the second ground plane.

14. The method of claim 13, further comprising coupling a button-type battery to the transponder module, the button-type battery having a first electrode coupled to the ground plane and a second electrode coupled to the power supply input to the RF engine.

15. The method of claim 13, wherein the RF engine comprises a small outline integrated circuit.

16. A method of tagging an object having a conductive surface comprising:

coupling a transponder module including a low profile antenna to the conductive surface such that a ground plane contained in the transponder module is adjacent the conductive surface of the object;

transmitting a signal from the low profile antenna to an interrogator, the signal including information relevant to the object;

receiving an interrogation signal by an inverted-F receive antenna contained in the transponder module; and

wherein transmitting a signal comprises transmitting a signal including information relevant to the object from an inverted-F backscatter antenna contained in the module.

17. A method of tagging an object having a conductive surface comprising:

coupling a transponder module including a low profile antenna to the conductive surface such that a ground plane contained in the transponder module is adjacent the conductive surface of the object;

transmitting a signal from the low profile antenna to an interrogator, the signal including information relevant to the object; and

receiving an interrogation signal by a receive antenna including an active element that is one-fourth of a wavelength in length.

18. A method of tagging an object having a conductive surface comprising:

coupling a transponder module including a low profile antenna to the conductive surface such that a ground plane contained in the transponder module is adjacent the conductive surface of the object; and

transmitting a signal from the low profile antenna to an interrogator, the signal including information relevant to the object, wherein transmitting a signal comprises transmitting a signal including information relevant to the object from a backscatter antenna including an active element that is less than one-fourth of a wavelength in length.

19. A method of tagging an object having a conductive surface comprising:

coupling a transponder module including a low profile antenna to the conductive surface such that a ground plane contained in the transponder module is adjacent the conductive surface of the object;

transmitting a signal from the low profile antenna to an interrogator, the signal including information relevant to the object; and

receiving an interrogation signal by a receive antenna including an active element that is one-fourth of a wavelength in length; and

wherein transmitting a signal comprises transmitting a signal including information relevant to the object from a backscatter antenna including an active element that is less than one-fourth of a wavelength in length.