Research of broad-beam circularly-polarized cross dipole antenna with declined tails

The cross dipole antenna (CDA) with pendulous tails is researched in this paper for widening beamwidth and fitting the dome radome. A 90° self-phase shifting structure is used for circularly polarized (CP) wave achieving by adjusting the proportion of the orthogonal arm lengths. A hybrid feeding is applied for widening bandwidth using both slotted coaxial Balun and microstrip impedance convertor. The tails of dipoles are declined to ground for widening beamwidth and reducing size. The electrical performances are researched with the change of dipole tail´s decline angle including voltage standing wave ratio (vswr), axial ratio (AR), AR patterns, gain and gain patterns. The final antenna obtained 8.8% relative operating bandwidth with AR<;3dB, vswr<; 1.5 and beamwidth> 130°.