Smartcard with coupling frame and method of increasing activation distance of a transponder chip module

1. A coupling frame (CF) for a smartcard (SC), comprising:

a metal layer (ML) having an opening (MO) for receiving a transponder chip module;

and a discontinuity, comprising a slit (S) or a non-conductive stripe (NCS), extending from the opening to a periphery of the metal layer.

2. The coupling frame of claim 1 , wherein:

the coupling frame is substantially coplanar with an antenna structure (AS) in the transponder chip module.

3. The coupling frame of claim 1 , wherein:

at least a portion of the coupling frame overlaps at least a portion of an antenna structure (AS) in the transponder chip module (TCM).

4. The coupling frame (CF) of claim 1 , wherein:

the transponder chip module (TCM) comprises an etched antenna structure (AS, LES); and

the module opening (MO) is spaced from 50 μm to 300 μm from the antenna structure.

5. The coupling frame (CF) of claim 1 , wherein:

the metal layer (ML) has a thickness greater than a transparency threshold for a material of the metal layer (ML).

6. A method of enhancing coupling of a transponder chip module (TCM) with an external reader, wherein the transponder chip module is disposed in a card body (CB, MCB) of a smart card having a metal layer (ML) and comprises an antenna structure (AS), characterized by:

forming the metal layer as a coupling frame (CF) closely adjacent to and surrounding the transponder chip module, wherein the coupling frame has an opening for receiving the transponder chip module and a slit (S) or a non-conductive stripe (NCS), extending from the opening to a periphery of the metal layer.

7. The method of claim 6 , wherein:

the coupling frame is substantially coplanar with the antenna structure (AS).

8. A smartcard comprising:

a transponder chip module comprising an RFID chip and an antenna; and

a coupling frame, comprising:

a metal layer;

an opening in the metal layer for receiving the transponder chip module; and

a discontinuity, comprising a slit or a non-conductive stripe, extending from the opening to a periphery of the metal layer;

wherein the coupling frame is disposed coplanar with the transponder chip module.

9. The smartcard of claim 8 , wherein, when the transponder chip module is disposed in the opening, the smartcard is characterized by at least one of:

the coupling frame is disposed closely adjacent to the transponder chip module; and

a portion of the coupling frame overlaps a portion of an antenna structure (AS) in the transponder chip module.

10. The smartcard of claim 8 , wherein the smartcard is characterized by at least one of:

the coupling frame extends over substantially the entire area of the smartcard;

the metal layer comprises a metal card body (MCB) of a metal smartcard.

11. The smartcard of claim 8 , wherein the slit is characterized by at least one of:

the slit extends completely through the metal layer;

the slit extends only partially through the metal layer, and remaining material of the metal layer below the slit has a thickness below a transparency threshold for the metal layer;

the slit has a width which is smaller than the opening;

the slit is at least partially filled with an electrically non-conducting material selected from the group consisting of polymer and epoxy resin, reinforced epoxy resin; and

a reinforcing structure (RS) disposed at a location of the slit (S) to reinforce the metal layer (ML).

12. The smartcard of claim 8 , wherein the metal layer comprises a material having a thickness selected from the group consisting of:

a thickness greater than a transparency threshold for absorbing electromagnetic waves at a frequency of interest;

a thickness greater than a skin depth for conducting electricity at a frequency of interest;

a thickness greater than 1 μm;

a thickness greater than 30 μm; and

a thickness up to the total normal thickness of a smartcard.

13. The smartcard of claim 8 , wherein the metal layer is characterized by at least one of:

the metal layer comprises a material selected from the group consisting of copper, aluminum, brass, titanium, tungsten, stainless steel, silver, graphene, silver nanowires and conductive carbon ink;

the metal layer is disposed on a non-conductive layer by a process selected from the group consisting of silk screen printing and vapor deposition;

the metal layer comprises a mesh; and

the metal layer comprises an engraving, embossing, or stamped feature/logo/ID which serves as a security feature for the smartcard.

14. The smartcard of claim 8 , wherein a gap between an inner edge of the coupling frame and an outer feature of an antenna structure (AS) in the transponder chip module is characterized by at least one of:

the gap is less than 300 μm; and

the gap is approximately 50 μm.

15. The smartcard of claim 8 , wherein:

the metal layer (ML) is substantially coplanar with an antenna structure (AS) in the transponder chip module.

16. The smartcard of claim 8 , wherein:

an antenna structure (AS) in the transponder chip module comprises a substantially planar, etched structure having a number of tracks separated by spaces.

17. The smartcard of claim 16 , wherein the spaces between tracks are at least one of:

less than 100 μm;

less than 75 μm;

less than 50 μm;

less than 25 μm; and

less than the width of a laser beam.

18. The smartcard of claim 8 , wherein

an activation distance for a transponder chip module disposed in the opening of the coupling frame is at least one of:

at least 20 mm;

at least 25 mm;

at least 30 mm;

at least 35 mm; and

at least 40 mm.

19. The smartcard of claim 8 , further comprising at least one of:

a switch (SW) connected across ends of the coupling frame (CF); and

an LED connected across ends of the coupling frame (CF).