Coupling in and to RFID smart cards

摘要

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).

主权项

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.