Design and development of a patch antenna for ISM band passive RFID tag

This work deals with the design and simulation of a passive radio frequency identification (RFID) tag antenna operating in ISM band. The antenna has an impedance bandwidth of 60 MHz (2419MHz - 2479 MHz) resonant at 2449.5 MHz. The microstrip antenna has a planar geometry and consists of a ground plane, a substrate, a modified rectangular patch as a radiator. The proposed antenna provides excellent SWR of 1.0435 and a gain of 3.351 dB. The possible adjustment over the entire ISM band is demonstrated by adjusting a single branch. The basic theory and design are analyzed, and the simulation results are obtained using CST Microwave Studio commercial software is employed to optimize the antenna's properties.