A broadband horizontally polarised omnidirectional antenna with stable radiation patterns

Abstract

A broadband horizontally polarised omnidirectional antenna (HPOA) with stable radiation patterns is proposed. The antenna is composed of two orthogonal broadband HPOA units fed by a wideband power divider. Each HPOA consists of four modified Vivaldi antennas fed by a 1‐to‐4‐way wideband power divider. The four Vivaldi antennas are etched on a circular substrate. The proposed antenna is simulated and discussed. Simulation results demonstrate that the designed antenna obtains a bandwidth of 88.9% from 2.5 to 6.5 GHz with reflection coefficients less than −10 dB, and the antenna gains are higher than 2 dBi in the whole frequency band. The antenna shows omnidirectional radiation feature with ripples less than 4.8 dB in the horizontal plane. The proposed antenna is suitable for 4G‐LTE and 5G communication systems.