A Wideband Circularly Polarized Antenna With Stepped-Shaped Patch

A wideband right-handed circularly polarized antenna fed by a tapered balun has been proposed. The antenna consists of a pair of rotationally symmetrical Z-shaped patches, a vertical tapered balun and a ground plane. The components of the Z-shaped patches include the stepped patches for generating circularly polarized waves, the rectangular patches and the trapezoidal patches which are connected to the ends of the balun. The obtained results can confirm that the proposed antenna has achieved a wide impedance bandwidth of 89% (1.33-3.5 GHz) and the 3-dB axial ratio bandwidth of 63% (1.56-3.0 GHz) with stable radiation patterns and a consistent gain across the operating frequency band with the minimum value above 5.0 dBi.