Physics-based approach for antenna design optimization of RFID tags mounted on and inside material layers

A design approach is presented for UHF RFID tag antennas operating in the vicinity of dielectric media using the layered Green´s function and the effective permittivity of a material with finite thickness. It is noted that materials detune the antenna and alter the gain pattern. In this work we propose a broadband tag antenna design that functions on materials across various permittivity and thicknesses. The analytic approach allows optimal placement to be determined within the dielectric. Experimental results show that the proposed tag achieves better performance when mounted on a wide range of materials as compared to commercial tags.