US Patent 7793849 Contactless identification device

A contactless identification device includes a flat conducting structure as an electromagnetic sensor or transducer. An electromagnetic sensor architecture is suitable for all applications where contactless or hybrid cards are of advantage: high volume paying and toll applications (public transportation, public sport events, person and good identification, access to controlled areas, control of shipment of goods, handling of luggage, product control in chain production environments), etc. The contact-less identification device has had its performance enhanced by the use of space-filling techniques in the design of its electromagnetic sensor and by the use of a planar capacitor in conjunction with said flat conducting structure.