UHF RFID Reader Antenna for Near-Field and Far-Field Operations

In this letter, a radio frequency identification (RFID) reader antenna designed for near-field and far-field operation at the European ultrahigh frequency (UHF) band is presented. Segmented loop technique is implemented for near-field operation, whereas a patch antenna is included inside the loop for far-field operation. The fabricated antenna works from 864 to 873 MHz with reflection coefficient less than 10 dB, thus covering the European UHF RFID band. Its linearly polarized radiation pattern provides a 4-dBi gain. The reading capabilities of the antenna are up to 9 cm and 6 m for near-field and far-field applications, respectively.