Coupling in and to RFID smart cards

• US 9,165,240 B2
• Filed: 12/28/2012
• Issued: 10/20/2015
• Est. Priority Date: 10/15/2009
• Status: Active Grant

• Current Assignee: AmaTech Group Limited (Paragon Group Limited)
• Original Assignee: Féinics AmaTech Teoranta (Paragon Group Limited)
• Inventors: Finn, David, Ummenhofer, Klaus
• Primary Examiner(s): Haupt, Kristy A
• Application Number:
  US13/730,811
• Publication Number:
  US 20140014732A1
• Time in Patent Office: 1,026 Days
• Field of Search: 235/492
• US Class Current: 1/1
• CPC Class Codes: G06K 19/077 Constructional details, e.g. mounting of circuits in the carrier
• CPC Class Codes: G06K 19/07747 at least one of the integrated circuit chips being mounted as a module
• CPC Class Codes: G06K 19/07756 the connection being non-galvanic, e.g. capacitive
• CPC Class Codes: G06K 19/07769 the further communication means being a galvanic interface, e.g. hybrid or mixed smart cards having a contact and a non-contact interface
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2924/20758 larger or equal to 80 microns less than 90 microns
• CPC Class Codes: H05K 1/0239 Signal transmission by AC coupling
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/09036 Recesses or grooves in insulating substrate recess in metallic substrate H05K2201/09745
• CPC Class Codes: H05K 2201/10098 Components for radio transmission, e.g. radio frequency identification [RFID] tag, printed or non-printed antennas
• CPC Class Codes: H05K 2201/10287 Metal wires as connectors or conductors
• CPC Class Codes: H05K 2203/0285 Using ultrasound, e.g. for cleaning, soldering or wet treatment
• CPC Class Codes: H05K 3/103 by bonding or embedding conductive wires or strips

Abstract

A dual interface (DI) smart card (100) comprising a chip module (CM), a module antenna (MA), a card body (CB) and a card antenna (CA) having two windings (D,E) connected with reverse phase as a “quasi-dipole”. Capacitive stubs (B,C) connected with an antenna structure (A) of the module antenna (MA). The module antenna (MA) overlaps only one of the windings (D or E) of the card antenna (CA). The card antenna (CA) may be formed from one continuous wire. Ferrite (156) shielding the module antenna (MA) from contact pads (CP) and for enhancing coupling between the module antenna (MA) and the card antenna (CA). The card antenna (CA) may be disposed substantially only in a top half portion of the card body (CB).

Claims

1. A card body for a smart card, comprising:

a card antenna extending at least partially around a periphery of a surface of the card body;

wherein the card antenna comprises two windings, an inner winding and an outer winding, connected in reverse phase with one another.

2. The card body of claim 1, wherein the two windings of the card antenna comprise:

an outer winding having an outer end and an inner end;

an inner winding having an outer end and an inner end; and

the inner end of the inner winding is connected with the outer end of the outer winding.

3. The card body of claim 2, wherein:

the inner end of the outer winding and the outer end of the inner winding are unconnected.

4. The card body of claim 1, wherein the card antenna occupies only approximately a top half the card body.

5. The card body of claim 4, wherein the card antenna extends along substantially all of a top edge of the card body, and only approximately halfway down right and left edges of the card body, and across a central portion of the card body.

6. The card body of claim 4, wherein the card antenna comprises an outer winding and an inner winding and is configured as quasi-dipole.

7. The card body of claim 6, wherein an outer end of the outer winding is connected with an inner end of the inner winding, and the inner end of the outer winding and inner end of the inner winding are left unconnected as free ends.

8. The card body of claim 4, wherein a pitch of turns of the coupler antenna varies across a width of the card body.

15. The antenna module of claim 2, wherein:

the first antenna structure is disposed on a first layer; and

at least one of the second and third antenna structures are disposed on second layer.

16. The antenna module of claim 15, wherein:

another of the second and third structures is disposed on a third layer.

9. A method of improving coupling with a smart card comprising:

providing a card antenna in the smart card, the card antenna having two winding portions, an inner winding and an outer winding, disposed on a surface of a card body, and connected in reverse phase with one another.

10. The method of claim 9, further comprising:

connecting an inner end of an inner of the two windings with an outer end of an outer of the two windings.

11. The method of claim 10, further comprising:

leaving an inner end of the outer winding and an outer end of the inner winding unconnected.

12. Antenna module for a smart card, the antenna module comprising at least one chip or chip module and a module antenna, wherein the module antenna comprises:

a first antenna structure in the form of a coil having first and second ends;

a second antenna structure in the form of a coil having first and second ends;

a third antenna structure in the form of a coil having first and second ends;

the first end of the second antenna structure is connected with the first end of the first antenna structure and to a first terminal of the chip module, the second end of the second antenna structure is left unconnected; and

the first end of the third antenna structure is connected with the second end of the first antenna structure and to a second terminal of the chip module, the second end of the third antenna structure is left unconnected.

13. The antenna module of claim 12, wherein at least one of the first, second and third antennas is in the form of a coil.

14. The antenna module of claim 12, wherein each of the first, second and third antennas is in the form of a coil.

17. The antenna module of claim 12, wherein:

the first antenna structure is disposed on a first layer; and

the second and third antenna structures are disposed on a second layer.

18. The antenna module of claim 12, wherein:

the second and third antenna structures are aligned with one another.

19. The antenna module of claim 12, wherein:

the second and third antenna structures are formed by a process other than embedding wire.

20. The antenna module of claim 12, wherein the antenna module further comprises:

contact pads for a contact mode of operation.