Axial mode helical antenna with circular prasitic rings for gain enhancement

This paper proposed a helical antenna in which circular parasitic rings are arranged inside a helical antenna. Compared to the gain boosting technique the traditional helical antenna, the height of the additional antenna does not increase. The gain of the proposed antenna is enhanced by a maximum of 2.5 dB in the working bandwidth by adding circular parasitic rings, while maintaining the Axial Ratio(AR) below the 3 dB. The simulation results and experimental results are used to confirm the gain and AR of the proposed antenna.