Design of Circularly Polarized Unidirectional Antenna using Probe-Excited Circular Ring Antenna above the Square Reflector with Inserted Metallic Slabs

摘要

This paper proposes a circularly polarized unidirectional antenna using a probe excited circular ring with inserted perpendicular slabs above the square reflector for UHF-RFID system. The measured |S_(11)| ≤ -10 dB covers 884 - 1000 MHz or 12.31% bandwidth, and 3-dB AR bandwidth of 900 - 1000 MHz or 10.53% bandwidth. The maximum gain is 8.35 dBic. The half-power beamwidths in xz- and yz-planes are 66.3 and 66.7 degrees, respectively.