Simplified design approach of rectangular spiral antenna for UHF RFID tag

In this paper we present a method to simplify the calculation of spiral antennas for RFID tag settings without resorting to numerical analysis methods. It saves up to 99% of the time required by the simulation based on the method of moments. Thus we present a theoretical and experimental study for the design of the spiral antennas for RFID label in the UHF band. We present in this study the S11 parameter that enables us to evaluate the evolution of current distribution and therefore the resonance frequency of the spiral antennas. This parameter is calculated theoretically by applying the method of moments to wired antenna formed by the rectangular copper spiral printed on a dielectric substrate. The experimental validation of our theoretical models is performed using a network analyzer. The confrontation theory-experience allows us to draw some interesting conclusions concerning the number of loops of the spiral and the choice of dielectric substrate.