An Omnidirectional Multi-Band Electrically Small Antenna Fed by Coplanar Waveguide

In this paper, an omnidirectional multiband electrically small antenna fed by coplanar waveguide has been proposed. We load corrugated metal ring structure with supporting spoof localized surface plasmons based on the traditional monopole antenna fed by coplanar waveguide. That not only maintains the characteristics of the omni-directivity of the antenna, but also reduces the electrical size of the antenna and generates multiple frequency bands. The impedance matching is further improved and the gain at high frequency is increased by loading a half of elliptic-shaped slot at the terminal of the corrugated metal ring structure. The performance of the antenna is verified by CST software. The resonant frequency points are 0.87GHz, 1.73GHz and 2.42GHz, respectively. The corresponding gains are 0.676dBi, 1.1dBi and 2.94dBi, respectively. The proposed antenna has a broad application in the field of base station antenna, electromagnetic compatibility and Internet of Things.