A bent, crossed-wire antenna with vertical parasitic elements: Formation of a circularly polarized conical beam

A novel crossed-wire antenna backed by a ground plane is proposed and analyzed using the method of moments. Two wires are crossed and fed in phase at the crossing point to radiate a conical beam. To make the conical beam circularly polarized, the crossed wires are bent and four vertical parasitic elements (PE) are added. The antenna is characterized by its simple feed and CP radiation at low elevation angles. First, the effects of the PE location on the radiation characteristics are investigated for crossed wires of a half wavelength. When the PE location is appropriately chosen, the antenna radiates a CP conical beam. Next, attention is paid to CP radiation in a wide range of elevation angle. Calculations show that the angle range where the axial ratio is less than 3 dB increases to 65° from 15° for a changed crossed-wire length. The maximum CP radiation is obtained at an elevation angle of 35°. Finally, the frequency characteristics are studied and the bandwidth for a 3-dB axial ratio criterion is found to be 8%.