RFID enabled metal transaction cards
A transaction card (smartcard) having a front “continuous” (with no slit) metal layer (ML, CML) with an opening (MO) for a dual-interface transponder chip module (TCM) having a module antenna (MA) on its bond side. A magnetic shielding layer (MSL) comprising ferrite material disposed below the front face continuous metal layer. An amplifying element, booster antenna circuit (BAC) disposed under the magnetic shielding layer. A rear discontinuous metal layer (ML, DML) with a slit (S) and a metal ledge surrounding the module opening to function as a coupling frame (CF). A rear plastic layer formed of non-RF impeding material may support a magnetic stripe and security elements (signature panel and hologram). A portion of the front face continuous metal layer may protrude downward into the magnetic shielding layer and booster antenna circuit layer. The rear discontinuous metal layer may have an additional slit to regulate the activation distance.
1. Smartcard, capable of at least contactless operation, comprising:
a front face continuous metal layer (ML, CML) without a slit and having a first module opening (MO);
a rear discontinuous metal layer (ML, DML) having a metal ledge surrounding a second module opening (MO) and a slit (S);
a transponder chip module (TCM) with a module antenna (MA); and
an assembly of at least one of a magnetic shielding layer (MSL) and a booster antenna circuit (BAC) disposed between the front face continuous metal layer and the rear discontinuous metal layer;
wherein:
the booster antenna circuit (BAC) comprises a perimeter coil (PC) and a coupler coil (CC); and
the booster antenna circuit comprises a closed loop circuit with no open-ended antenna elements;
further comprising:
an integrated parallel plate capacitor bank comprising upper electrodes (UE) and lower electrodes (LE) attached in parallel to the perimeter coil and coupler coil for frequency trimming.
2. The smartcard of claim 1 , wherein:
the magnetic shielding layer is disposed behind the front face continuous metal layer; and
the booster antenna circuit is disposed behind the magnetic shielding layer.
3. The smartcard of claim 1 , wherein:
the rear discontinuous metal layer (DML) with a slit (S) which terminates in a module opening (MO), is provided with at least one additional slit arranged on another side of the discontinuous metal layer.
4. Smartcard, capable of at least contactless operation, comprising:
a front face continuous metal layer (ML, CML) without a slit and having a first module opening (MO);
a rear discontinuous metal layer (ML, DML) having a metal ledge surrounding a second module opening (MO) and a slit (S);
a transponder chip module (TCM) with a module antenna (MA); and
an assembly of at least one of a magnetic shielding layer (MSL) and a booster antenna circuit (BAC) disposed between the front face continuous metal layer and the rear discontinuous metal layer;
wherein:
the module antenna (MA) of the transponder chip module (TCM) is arranged concentrically to overlap the coupler coil (CC) of the booster antenna circuit (BAC) and a metal ledge surrounding the module opening (MO) in the rear discontinuous metal layer.
5. The smartcard of claim 4 , wherein:
the magnetic shielding layer is disposed behind the front face continuous metal layer; and
the booster antenna circuit is disposed behind the magnetic shielding layer.
6. The smartcard of claim 4 , wherein:
the booster antenna circuit (BAC) comprises a perimeter coil (PC) and a coupler coil (CC); and
the booster antenna circuit comprises a closed loop circuit with no open-ended antenna elements.
7. The smartcard of claim 4 , wherein:
the rear discontinuous metal layer (DML) with a slit (S) which terminates in a module opening (MO), is provided with at least one additional slit arranged on another side of the discontinuous metal layer.
8. Smartcard, capable of at least contactless operation, comprising:
a front face continuous metal layer (ML, CML) without a slit and having a first module opening (MO);
a rear discontinuous metal layer (ML, DML) having a metal ledge surrounding a second module opening (MO) and a slit (S);
a transponder chip module (TCM) with a module antenna (MA); and
an assembly of at least one of a magnetic shielding layer (MSL) and a booster antenna circuit (BAC) disposed between the front face continuous metal layer and the rear discontinuous metal layer;
wherein:
the underside of the front face continuous metal layer has a protruding boss which extends through the card assembly to the rear discontinuous metal layer.
9. The smartcard of claim 8 , wherein:
the protruding boss adds weight to the smartcard, enhances a metal sound and provides for mechanical robustness.
10. The smartcard of claim 8 , wherein:
the magnetic shielding layer is disposed behind the front face continuous metal layer; and
the booster antenna circuit is disposed behind the magnetic shielding layer.
11. The smartcard of claim 8 , wherein:
the booster antenna circuit (BAC) comprises a perimeter coil (PC) and a coupler coil (CC); and
the booster antenna circuit comprises a closed loop circuit with no open-ended antenna elements.
12. The smartcard of claim 8 , wherein:
the rear discontinuous metal layer (DML) with a slit (S) which terminates in a module opening (MO), is provided with at least one additional slit arranged on another side of the discontinuous metal layer.
13. A smartcard, comprising:
a front metal layer (ML, FML) without a slit and having a first module opening (MO);
a rear metal layer (ML, RML) having a second module opening (MO) and a slit (S); and
a booster antenna circuit (BAC) disposed between the front face metal layer and the rear metal layer;
wherein the booster antenna circuit (BAC) comprises a perimeter coil (PC) and a coupler coil (CC); and
wherein outer windings of the perimeter coil are arranged to be as close as possible to an outer peripheral edge of the rear metal layer;
wherein:
the outer windings of the perimeter coil are within 500 μm of the outer edge of the rear metal layer.
14. The smartcard of claim 13 , wherein:
at least some windings of the perimeter coil overlap the slit.
15. The smartcard of claim 13 , further comprising:
a metal ledge surrounding the second module opening;
wherein the coupler coil overlaps the metal ledge.
16. The smartcard of claim 13 , further comprising:
a magnetic shielding layer disposed between the front metal layer and the rear metal layer.
17. The smartcard of claim 13 , further comprising:
a transponder chip module (TCM) having a module antenna (MA) disposed in the module openings.
18. The smartcard of claim 13 , wherein:
the transponder chip module has the module antenna (MA) and contact pads (CP) for dual interface capability.
19. The smartcard of claim 13 , further comprising:
frequency trimming capacitor electrodes.