Artificial magnetic conductor loaded long-range passive RFID tag antenna mountable on metallic objects

A passive radio frequency identification (RFID) tag antenna providing a long recognition distance is proposed, which is mountable on various types of platforms including metallic and highly dielectric objects. To increase the reading distance, the antenna is installed in a recessed metallic cavity. To reduce further the height of the antenna, an artificial magnetic conductor is placed on the bottom face of the cavity. Consequently, the tag antenna not only can be miniaturised, but also can provide long reading distances on any type of platform objects. The measured maximum reading distance and the minimum sensitivity are 12.2 m and -17 dBm, under a reader transmitting 30 dBm with a 6 dBi antenna. Good agreement between the prediction and experimental results verifies that the approach is fairly effective and useful to substantially increase the reading distance.