A circularly polarized (CP) elliptical-ring slot antenna is proposed. A tapered slot is excited by an L-shaped coupling strip. A good impedance match is obtained, and an excellent CP characteristic is achieved. The antenna has been investigated numerically, and prototype of the presented antenna is fabricated and tested. The measured results show that the antenna has a bandwidth of 37.5% (3.9 GHz-5.7 GHz) for return loss less than -10 dB and 34.7% (3.8 GHz-5.4 GHz) for average axial ratio (AR) less than 3 dB. The proposed antenna provides good CP performance.
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