Radio frequency data communications device with adjustable receiver sensitivity and method

• US 6,781,508 B2
• Filed: 12/09/2002
• Issued: 08/24/2004
• Est. Priority Date: 07/30/1996
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: John R. Tuttle, TUTTLE, MARK E.
• Inventors: Tuttle, John R., Tuttle, Mark E.
• Primary Examiner(s): ZIMMERMAN, BRIAN A
• Application Number:
  US10/315,427
• Publication Number:
  US 20030080853A1
• Time in Patent Office: 624 Days
• Field of Search: 340/572.7, 340/10.1, 340/573.1, 340/572.1, 340/572.2, 340/10.2, 343/795
• US Class Current: 340/10.1
• CPC Class Codes: G01S 13/767 Responders; Transponders teaching or practice apparatus for gun-aiming or gun-laying using reflecting targets or active targets F41G3/26
• CPC Class Codes: G01S 13/78 discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe G01S13/75, G01S13/79 take precedence
• 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 7/10346 the antenna being of the far field type, e.g. HF types or dipoles
• CPC Class Codes: H01L 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• 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 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

An adjustable radio frequency data communications device has a monolithic semiconductor integrated circuit with integrated circuitry, interrogation receiving circuitry provided on the monolithic integrated circuit forming at least part of the integrated circuitry and configured to receive an interrogation signal from the interrogator unit, an antenna electrically coupled to the interrogation receiving circuitry and configured to communicate with the remote interrogator unit, a power source electrically coupled to the integrated circuitry and configured to generate operating power for the communications device, and at least one of the antenna and the interrogation receiving circuitry having reconfigurable electrical characteristics, the electrical characteristics being reconfigurable to selectively tune the at least one of the antenna and the interrogation receiving circuitry within a range of tuned and detuned states to realize a desired receiver sensitivity of the communications device.

Claims

1. A method of manufacturing a radio frequency data communications device, for use with a remote interrogator unit, the method comprising:

providing an RFID integrated circuit, including a package housing transponder circuitry, and supporting the integrated circuit on a substrate, the integrated circuit being configured to transmit, in response to an interrogation signal from a remote interrogator, a responsive signal which includes identification information;

securing an antenna on the substrate external of the transponder circuitry and electrically coupling the antenna to the integrated circuit, the antenna having a length, and a width transverse to the length;

purposefully reducing the sensitivity of the transponder circuitry of the integrated circuit by trimming the antenna to reduce the width of at least a portion of a section at a location along the length of the antenna, while the antenna is on the substrate; and

supporting a battery from the substrate and coupling the battery to the integrated circuit, wherein reducing the sensitivity of the transponder circuitry comprises setting a range of twenty feet for the transponder circuitry, increasing duration of an interval during which the transponder circuitry is not able to detect a wake-up signal and conserving battery power.

2. A method in accordance with claim 1 and further comprising permanently encapsulating the battery, the RFID integrated circuit and the antenna.

3. A method of manufacturing a radio frequency data communications device, for use with a remote interrogator unit, the method comprising:

providing an RFID integrated circuit, including a package housing transponder circuitry, and supporting the integrated circuit on a substrate, the integrated circuit being configured to transmit, in response to an interrogation signal from a remote interrogator, a responsive signal which includes identification information;

supporting an antenna on the substrate external of the transponder circuitry, and electrically coupling the antenna to the integrated circuit, the antenna having a length, and a width transverse to the length;

purposefully reducing the sensitivity of the transponder circuitry of the integrated circuit by trimming the antenna to reduce the width of at least a portion of a section at a location along the length of the antenna, while the antenna is on the substrate; and

supporting a battery from the substrate and coupling the battery to the integrated circuit.

4. A method in accordance with claim 3 and further comprising permanently encapsulating the battery, the RFID integrated circuit and the antenna.

5. A method of manufacturing a radio frequency data communications device, for use with a remote interrogator unit, the method comprising:

providing first transponder circuitry on a sheet substrate;

printing an antenna on the sheet substrate, external of the transponder circuitry, and electrically coupling the antenna to the transponder circuitry;

providing a battery on the substrate and electrically coupling the battery to the first transponder circuitry; and

trimming the antenna by a first amount, while the antenna is on the substrate, to effect a first sensitivity; and

providing second transponder circuitry on a second sheet substrate;

printing a second antenna using printed thick film, on the second sheet substrate, external of the second transponder circuitry, and electrically coupling the second antenna to the second transponder circuitry;

providing a second battery on the second sheet substrate and electrically coupling the second battery to the second transponder circuitry; and

trimming the second antenna, while the second antenna is on the second sheet substrate, by an amount different from the first amount to effect a second sensitivity different from the first sensitivity, wherein trimming the antenna by the first amount comprises setting a transmission distance for the first transponder circuitry.

6. A method in accordance with claim 5 wherein providing the first transponder circuitry and providing the second transponder circuitry comprises providing integrated circuits comprising transponder circuitry.

7. A method in accordance with claim 5 wherein trimming the second antenna comprises setting a range of twenty feet for the second transponder circuitry, increasing duration of an interval during which the second transponder circuitry is not able to detect a wake-up signal and conserving battery power.

8. A method in accordance with claim 5 and further comprising sealing together the first transponder circuitry, the antenna and the battery.

9. A method of manufacturing a radio frequency data communications device, for use with a remote interrogator unit, the method comprising:

providing transponder circuitry on a substrate;

forming a first antenna, having a first sensitivity, on the substrate, external of the transponder circuitry, and electrically coupling the antenna to the transponder circuitry;

providing a battery on the substrate and electrically coupling the battery to the transponder circuitry; and

trimming the antenna by a first amount, while the antenna is on the substrate, and setting the transponder circuitry for operation at a predetermined frequency; and

providing second transponder circuitry on a second substrate;

forming a second antenna, having a second sensitivity different than the first sensitivity, on the second substrate, external of the second transponder circuitry, and electrically coupling the second antenna to the second transponder circuitry;

providing a second battery on the second substrate and electrically coupling the second battery to the second transponder circuitry; and

setting the second transponder circuitry for operation at the predetermined frequency, wherein setting the first sensitivity results in limiting the range for the first transponder circuitry.

10. A method in accordance with claim 9 wherein setting the first sensitivity results in increasing duration of an interval during which the first transponder circuitry is not able to detect a wake-up signal.

11. A method in accordance with claim 9 further comprising sealing the transponder circuitry, the antenna and the battery on the substrate.

12. A method of manufacturing a radio frequency data communications device, for use with a remote interrogator unit, the method comprising:

providing an RFID integrated circuit, including a package housing transponder circuitry, the integrated circuit being configured to transmit, in response to an interrogation by a remote interrogator, a responsive signal which includes identification information;

printing a conductive plastic microstrip antenna on the substrate, using conductive epoxy, external of the transponder circuitry and electrically coupling the microstrip antenna to the integrated circuit external of the integrated circuit, the microstrip antenna having a length, and a width transverse to the length;

reducing the sensitivity of the transponder circuitry of the integrated circuit by trimming the microstrip antenna to reduce the width of at least a portion of the section at a location along the length between the opposite ends, while the microstrip antenna is on the substrate; and

supporting a battery from the substrate and coupling the battery to the integrated circuit using conductive epoxy, wherein purposefully reducing the sensitivity of the transponder circuitry results in setting a range for the transponder circuitry.

13. A method in accordance with claim 12 and further comprising permanently sealing the RFID integrated circuit, the microstrip antenna and the battery in the package.

14. A method of manufacturing a radio frequency data communications device, for use with a remote interrogator unit, the method comprising:

providing an RFID integrated circuit, including a package housing transponder circuitry, and adhesively bonding the integrated circuit on a substrate, the integrated circuit being configured to transmit, in response to an interrogation by a remote interrogator, a responsive signal which includes identification information;

printing a generally planar dipole conductive antenna on the substrate, using conductive epoxy, external of the transponder circuitry and electrically coupling the antenna to the integrated circuit, external of the integrated circuit, the antenna having a length, and a width transverse to the length;

purposefully reducing the sensitivity of the transponder circuitry of the integrated circuit by trimming the antenna to reduce the width of at least a portion of the section at a location along the length between the opposite ends, while the antenna is on the substrate; and

supporting a battery from the substrate and coupling the battery to the integrated circuit using conductive epoxy, wherein reducing the sensitivity varies transmission distance of the transponder circuitry.

15. A method in accordance with claim 14 wherein the battery has a terminal and wherein the coupling of the battery to the integrated circuit comprises coupling a contact pad to the conductive epoxy and placing the terminal in contact with the conductive pad.

16. A method in accordance with claim 14 and further comprising permanently sealing the RFID integrated circuit, the antenna and the battery within the package.

17. A method of manufacturing a radio frequency data communications device, for use with a remote interrogator unit, the method comprising:

providing an RFID integrated circuit, including a package housing transponder circuitry, and supporting the integrated circuit on a substrate, the integrated circuit being configured to transmit, in response to an interrogation signal from a remote interrogator, a responsive signal which includes identification information;

printing a conductive antenna on the substrate, using conductive epoxy, external of the transponder circuitry and electrically coupling the antenna to the integrated circuit, external of the integrated circuit, the antenna having a length, and a width transverse to the length;

purposefully reducing the sensitivity of the transponder circuitry of the integrated circuit by trimming the antenna to reduce the width of at least a portion of a section at a location along the length of the antenna, while the antenna is on the substrate;

supporting a battery from the substrate and coupling the battery to the integrated circuit using conductive epoxy; and

permanently hermetically encapsulating the battery, the RFID integrated circuit and the antenna on the substrate, wherein reducing the sensitivity of the transponder circuitry results in reducing the range for the transponder circuitry relative to what the range would be without reducing the sensitivity.

18. A method of manufacturing a radio frequency data communications device, for use with a remote interrogator unit, the method comprising:

providing a first transponder circuitry and a first antenna on a sheet substrate;

electrically coupling the first antenna to the transponder circuitry;

providing second transponder circuitry and a second antenna on a second sheet substrate;

electrically coupling the second antenna to the second transponder circuitry; and

trimming the first and second antennas by differing amounts to effect differing sensitivities of the respective first and second antennas and to vary transmission distances for the respective first and second transponder circuitry.

19. The method of claim 18 wherein trimming the first and second antennas comprise laser trimming.

20. The method of claim 18 wherein providing the first and second antennas comprise providing first and second microstrip antennas.

21. A radio frequency data communications device for use with a remote interrogator unit, comprising:

a first transponder circuitry provided on a first sheet substrate;

a first antenna formed on the first sheet substrate and electrically coupled to the first transponder circuitry;

a second transponder circuitry provided on a second sheet substrate;

a second antenna formed on the second sheet substrate and electrically coupled to the second transponder circuitry; and

wherein the first and second antennas are trimmed by differing amounts to effect differing sensitivities of the respective first and second antennas, the differing sensitivities corresponding to differing transmission distances for the respective first and second transponder circuitry.

22. The apparatus of claims 21 wherein the first and second antennas are laser trimmed.

23. The apparatus of claim 21 wherein the first and second antennas comprise microstrip antennas.