Design of an ultra-wideband hemispherical helical antenna

A single arm hemisphere cylindrical helical antenna with equal arc distance is studied in this paper, which has the characteristics of broadband, small size, circular polarization, low profile and etc. The structure of hemisphere cylindrical helical antenna is employed. The equivalent L matching network is introduced in the feed port to make the impedance matched, which expanses the antenna bandwidth. The miniaturization, circular polarization and ultra-wideband of the antenna are realized. The structure parameters of hemisphere cylindrical helical antenna are optimized by HFSS simulation software. The simulation and test results show that the impedance bandwidth of the antenna is more than 30% and the axial ratio bandwidth of the antenna is more than 20%. In addition, the maximum gain of the antenna can achieve 9 dB. All these properties indicate that the antenna has good radiation characteristics.