An Ultra-wideband Circularly-polarized Vivaldi Antenna with Wide Beam Angel

A new kind of wide beam circular polarization UWB antenna is proposed in this paper. The antenna consists of four Vivaldi antennas placed along the edge of the square. A copper column is placed around the antenna, and a copper ring is parasitic on the periphery of the copper column to realize the broadening of the beam width. The impedance matching of antennas can be improved by adding metal holes between antennas. The simulation results show that the 10 dB impedance bandwidth (IBW) of the antenna is 97.8% (7.3-21 GHz), and the 3 dB axial specific bandwidth (ARBW) is 100% (7-21 GHz). The antenna beam Angle is relatively large, and the -5dBi beam Angle is greater than 90°.