A broadband horizontally polarised omnidirectional antenna with stable radiation patterns

摘要

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.