2.4GHz Yagi-Uda RFID tag antenna design with low back-lobe using genetic algorithm

A long reading range 2.4HGz Yagi-Uda RFID tag antenna with low back-lobe is designed. Since the EIRP (Effective Isotropic Radiation Power) of the reader is limited, to extend a reading range of the tag, the gain and front-backratio of the tag should be high as Yagi-Uda antenna. According to ISO 18000-4, the EIRP of the reader and reader antennas is about 30mW. It is lower than EIRP of UHF RFID band. The optimized 5 elements Yagi-Uda tag antenna with a genetic algorithm (GA) has low back-lobe. The 5 elements sizes and spacing of Yagi-Uda antenna are optimized with a GA. The gain of main-lobe is 8.2dB and back lobe is reduced to 0dB. The performance of the 2.4GHz Yagi-Uda type tag antenna is better than that of general type tag and conventional Yagi-Uda tag antennas.