A Novel Folded Dipoles Circularly Polarized Quasi-Yagi Antenna

A novel planar folded dipoles quasi-Yagi antenna with a good function is proposed. It is based on a simple structure of two pairs of folded dipoles, planar magnetic walls, two mental via-holes, and a director. The working principle of the antenna is studied and analyzed. The magnetic walls are combined with folded dipoles to form a circularly polarized beam. By simulation and optimization, The impedance bandwidth (|S
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|≤ - 10 dB) of about 4.8% (5.65-5.93 GHz) and a 3 dB AR bandwidth of about 13.3% (5.28-6.03 GHz) around the center frequency of 5.8 GHz is achieved, which indicates that the proposed antenna is suitable for the RFID system.