RFID tag antenna with a meandered dipole and inductively coupled feed

This paper presents tag antennas with an inductively coupled feed structure for the RFID application in the UHF band. The designed antennas consist of the rectangular loop for feeding and meandered dipole. We estimate the maximum bandwidth of the designed antenna using the approximate calculation and the calculated results are verified by measuring the read range of the tag antennas as a function of frequency. The read range of the designed RFID tag is approximately from 2.5 m to 4 m in air.