Proximity and dual interface metal cards and methods of making card bodies with two metal layers

Abstract

Proximity cards or contactless smartcards manufactured by folding a metal layer along one or two fold lines to form a metal card body (MCB) having the dimensions of a standard ID-1 smartcard. An antenna structure (AS) on a flexible or rigid circuit sandwiched powering an RFID chip may be disposed between the folded metal layer or metal layers. A smartcard (SC) characterized by a booster antenna (BA) arranged on a rear plastic layer laminated to a front metal layer (ML) having a slit (S). A sense coil (SeC) component may be arranged around the slit, and may overlap the slit in a zigzag fashion or the like. The sense coil may have a loop, spiral or helix shape. The booster antenna may form a closed loop circuit or an open loop circuit.

Dependencies are inferred from the claim text.