Circular polarization rectangular Dielectric Resonator Antenna for UHF RFID applications

A low profile circularly polarized RFID (radio frequency identification) reader antenna is designed and analysed for operation at the European ultra-high frequency (UHF) band, ranging from 865-868 MHz. The proposed Dielectric Resonator Antenna (DRA) is composed of microstrip line/slot feed and a rectangular dielectric resonator made from a high-permittivity (ε_r = 30). The simulated results show satisfactory performance versus size. The antenna works from 857 to 885 MHz, thus covering the European UHF RFID Band, and its circularly polarized radiation pattern provides a 3.75 dBi realized gain.