Design Of High Bandwidth Circularly Polarised Antipodal Vivaldi Array for 5G Applications

In this paper, a circularly polarized antenna array is proposed that has high gain and excellent axial ratio properties. The array is composed of multiple UWB antipodal slotted Vivaldi antennas that have been designed for a resonant frequency of 8.5 GHz and using orthogonal excitations to the array, circular polarization has been successfully achieved. Modified Wilkinson power splitter has been utilized to work over the range of 4-12 GHz and phase shifting has been achieved using aperture coupling techniques. The S parameters for the constructed system are excellent with return loss as low as -25dB and an axial ratio of almost 0.098 dB at the resonant frequency.