A new spiral antenna for passive UHF RFID tag on different substrates

This work presents the design of an antenna for UHF RFID tags for supply and retail market working on different substrates. This antenna is based on the principle of broadband and frequency independent antenna like spiral antenna, which in free space simulation has a reflection coefficient less than −7.5 dB over US UHF RFID frequency band. Material's effects on impedance matching and reading range of the proposed antenna have been investigated in simulation and experimentally. All simulations were performed using a simulator based on a finite element method like Ansoft HFSS. Prototypes were measured into an anechoic chamber.