Modeling of antenna geometry and thickness optimization for wideband UHF RFID tag

Abstract

In this paper, we present a novel design for wideband Ultra High Frequency (UHF) Radio Frequency Identification (RFID) passive tag. The optimized design has compact size and covers all the bandwidth for global UHF RFID (860MHz-960MHz). For flexible customization in real-world applications, an equivalent model of antenna geometry is also proposed in this work. The agreement between equivalent model with lumped elements and 3D EM simulation of antenna geometry in 2 different simulator (ADS and CST Microwave Studio) proves the feasibility of design in practical applications. Furthermore, we executed also the optimization of antenna thickness in order to reduce the price of commercial tags. From experimental results, the good agreement between simulation and measurement proves the feasibility of equivalent model and the repeatability of fabrication process. The optimized design has the acceptable read-range (over 8m) in all the bandwidth of global UHF RFID and optimized thickness for antenna should be between 5-μm and 6-μm to keep the good performance of fabricated RFID tags.