Low‐profile omnidirectional antenna with broad bandwidth and high gain

Abstract

In this study, a novel low profile wideband omnidirectional antenna is proposed. Horizontal dimension is utilized by introducing annular patches and near‐zero‐index metamaterials, instead of enhancing horizontal gain through increasing the profile of antenna. Measured results illustrate that horizontal gain of this antenna is enhanced to more than 2.5 dBi with 9.81% relative bandwidth (4.97−5.49 GHz) and low profile (0.034λ). Compared with other works, this novel antenna has obvious advantages in electromagnetic characteristics and physical structure, which has great potential in vehicular communications.