A planar wideband inductively coupled feed patch antenna for UHF RFID tag

A planar wideband patch antenna for ultra-high frequency (UHF) radio frequency identification (RFID) tag for metallic applications is presented in this research work. Three different shape patches are inductively coupled to a triangle loop to excite three resonances close to each other to form wide impedance bandwidth for universal application UHF (860-960 MHz) RFID. The structure of the proposed antenna exhibits planar profile to provide ease of fabrication for cost reduction well suited for mass production. The simulation of the antenna was carried out using Finite Element Method (FEM) based software, Ansoft HFSS v13. The performance of the design was verified by the simulation and measurement results which show good agreement. The simulated and measured impedance bandwidth of 113 MHz and 117 MHz (return loss ≥ 6 dB) was achieved to cover the entire UHF RFID operating frequency band worldwide.