UHF RFID antenna for ETSI and FCC reading applications

This paper presents the design of a UHF RFID reader antenna array suitable for applications in the frequency bands of ETSI and FCC standards. The antenna consists of geometrically alternating orthogonal elements (double-dipoles) which are fed in series and in phase by two parallel meander shaped microstrip lines and creates beams with direction diversity. Simulated and measured results confirmed that for 30 dBm input power level, a semi-cylindrical volume along the longitudinal axis of the antenna with a radius of 500 mm is sufficiently covered. The operating bandwidth (RL>13 dB) of the antenna is about 72 MHz (861-933 MHz) and covers both the frequency bands of ETSI and FCC standards. Assuming tag sensitivity based on the worst case scenario, experimental results verify that tagged items, which are randomly polarized within the coverage volume, can be properly identified regardless of their tag orientation.