A Novel Antenna Design for Passive RFID Transponders on Metal Surfaces

Metal poses a serious source of interference and loss of performance for RFID systems. This paper presents a novel antenna design for RFID transponder (tag) that enables long read/write range for tags mounted on metal surfaces. The antenna is constructed to exploit the deflection of the magnetic field operated by the metallic surface, coupling it in a coil oriented parallel with the surface. The criteria for optimizing the structure are based on EM numerical simulations and on the measurements of several prototypes