A Wideband Circularly Polarized Antenna With Conical-Beam Radiation

In this paper, a novel circularly polarized (CP) antenna is proposed to meet conical beam radiation. The designed antenna consists of a monopolar patch fed by a probe in the center, two sets of arc hook branches, a set of conductive shorting vias and a reflector plane. The monopolar patch which connects to ground plane by set of conductive shorting vias, whose two resonant modes are utilized to achieve wide impedance bandwidth. A horizontally polarized electric field and a vertical polarized electric field can be generated by the arc hook branches and the monopolar patch, respectively. To adjust the parameters of the arc hook branches appropriately, the conical beam CP radiation can be obtained. The proposed antenna has a wide impedance bandwidth (S-11 < -10 dB) of 17.5% (5.7 to 6.75 GHz) and a 3-dB AR bandwidth of about 26.5% (5.19 to 6.78 GHz). Moreover, the stable omnidirectional conical-beam radiation patterns can be maintained within the whole operation bandwidth.