Metallized smartcard constructions and methods
A dual-interface smartcard (SC) having a booster antenna (BA) with coupler coil (CC) in its card body, and a metallized face plate having a window opening for an antenna module (AM) having contact pads (CP) and a module antenna (MA). A compensation loop (CL) may be disposed directly behind a peripheral portion of the booster antenna. The compensation loop may be formed of a conductive material, such as copper, or of ferrite, and may have two free ends or no free ends. Additionally, the window opening may be substantially larger than the antenna module, the face plate may be perforated, ferrite material may be disposed between the face plate and the booster antenna, the coupler coil may be offset from the antenna, and a ferrite element may be disposed in the antenna module between the module antenna and the contact pads.
1. A smartcard comprising:
a card body (CB) comprising an inlay substrate having a peripheral area;
a booster antenna (BA) having a peripheral portion (CA) disposed in the peripheral area on one side of the inlay substrate; and
a compensation loop (CL) disposed in the peripheral area, behind the booster antenna, on an opposite side of the inlay substrate.
2. The smartcard of claim 1 , further comprising:
a metallized face plate with a window opening (W) for accepting an antenna module (AM).
3. The smartcard of claim 2 , wherein:
the window opening is substantially larger than the antenna module, resulting in a gap between inner edges of the window opening and the antenna module.
4. The smartcard of claim 2 , further comprising:
a ferrite layer disposed between the face plate and the booster antenna.
5. The smartcard of claim 2 , further comprising:
a plurality of perforations in the face plate extending around at least one of the window opening and the periphery of the face plate.
6. The smartcard of claim 1 , wherein:
the compensation loop has a gap, and two free ends.
7. The smartcard of claim 1 , wherein:
the compensation loop is formed as a continuous loop, with no free ends.
8. The smartcard of claim 1 , wherein:
the compensation loop comprises a conductive material.
9. The smartcard of claim 1 , wherein:
the compensation loop comprises ferrite.
10. The smartcard of claim 1 , wherein:
the compensation loop is aligned with and approximately the same size as the peripheral portion of the booster antenna.
11. The smartcard of claim 1 , further comprising:
an antenna module (AM) having an RFID chip, an antenna (MA), and contact pads (CP).
12. The smartcard of claim 11 , wherein:
the booster antenna includes a coupler coil (CC).
13. The smartcard of claim 12 , wherein:
the coupler coil is offset from the module antenna.
14. The smartcard of claim 11 , further comprising:
a ferrite element disposed between the module antenna and contact pads.
15. The smartcard of claim 11 , further comprising:
perforations in the contact pads.
16. The smartcard of claim 1 , further comprising:
ferrite material disposed between the face plate and the booster antenna.