Smartcards with multiple coupling frames
RFID devices comprising (i) a transponder chip module (TCM, 1410 ) having an RFIC chip (IC) and a module antenna (MA), and (ii) a coupling frame (CF) having an electrical discontinuity comprising a slit (S) or non-conductive stripe (NCS). The coupling frame may be disposed closely adjacent the transponder chip module so that the slit overlaps the module antenna. The RFID device may be a payment object such as a jewelry item having a metal component modified with a slit (S) to function as a coupling frame. The coupling frame may be moved (such as rotated) to position the slit to selectively overlap the module antennas (MA) of one or more transponder chip modules (TCM- 1 , TCM- 2 ) disposed in the payment object, thereby selectively enhancing (including enabling) contactless communication between a given transponder chip module in the payment object and another RFID device such as an external contactless reader. The coupling frame may be tubular. A card body construction for a metal smart card is disclosed.
1. A smart card comprising:
a transponder chip module comprising an RFID chip and a module antenna;
a first coupling frame comprising a conductive surface and having a first slit extending through the surface from an outer edge thereof to an inner position thereof, wherein the coupling frame is disposed so that the slit overlaps a portion of the module antenna; and
a second coupling frame comprising a conductive surface and having a second slit extending through the surface from an outer edge thereof to an inner position thereof, wherein the coupling frame is disposed so that the slit overlaps a portion of the module antenna.
2. The smartcard of claim 1 , wherein the first and second coupling frames are stacked on top of each other.
3. The smartcard of claim 2 , wherein the first and second coupling frames are separated by a dielectric material.
4. The smartcard of claim 2 , wherein the first and second coupling frames are separated by an insulating layer or film.
5. The smartcard of claim 1 , wherein the slits of the first and second coupling frames are disposed in different directions than one another.
6. The smartcard of claim 1 , wherein the first and second slits of the first and second coupling frames are disposed at different positions than one another.
7. The smartcard of claim 1 , wherein the first slit of the first coupling frame extends from a module opening in the first coupling frame in a first direction, wherein the second slit of the second coupling frame extends from a module opening in the second coupling frame in a second direction, the second direction being 180° from the first direction, and wherein the first and second coupling frames are interlocked with one another, so that the slit of one coupling frame engages the slit of the other coupling frame.
8. The smartcard of claim 1 , further comprising a third coupling frame comprising a conductive surface and having a slit extending through the surface from an outer edge thereof to an inner position thereof, wherein the third coupling frame is disposed so that its slit overlaps a portion of the module antenna.
9. The smartcard of claim 1 , further comprising contact pads so that the transponder chip module can function with dual interfaces.
10. The smartcard of claim 1 , wherein the first and second coupling frames are disposed co-planar with one another.
11. A card body construction for a smart card comprising:
a plurality of metal layers, each metal layer having a slit so that the metal layer may function as a coupling frame, wherein:
a first of the metal layers has a first opening for receiving a transponder chip module, and the slit of the first metal layer extends from the first opening to an outer edge of the first metal layer;
a second of the metal layers has a second opening for receiving a mold mass of the transponder chip module, and the slit of the second metal layer extends from the opening to an outer edge of the second metal layer so that the slit of the second metal layer overlaps at least a portion of a module antenna of the transponder chip module when the transponder chip module is inserted in the card body construction; and
the first and second openings in the first and second metal layers are aligned with one another.
12. The card body construction of claim 11 , wherein the first and second metal layers are separated by an adhesive layer.