Closely located RFID tag antennas on high dielectric objects

Sensitivity of the tag of radio frequency identification (RFID) system is one of the most important factors to evaluate the tag performance. The sensitivity is usually degraded when the tags are located very closely or when they are attached on the surface of high dielectric objects because the power transmission ratio between chip and antenna of the tag is decreased due to the impedance mismatching. In this paper, the tag antenna is designed and studied for the tag which is applied to the closely located applications and the high dielectric constant objects. Numerical study shows that the tag can keep a high power transmission ratio when they are used in the closely located applications and the high dielectric constant objects.