Elliptical helical antenna with parasitic wire for CP band enhancement

In this paper, elliptical helical antenna with parasitic element is proposed to radiate the circularly polarized waves. By winding a parasitic wire properly in parallel with the elliptical helical antenna, the axial ratio bandwidth is enhanced, and simple single feeding mechanism is maintained. The simulation by IE3D shows that the CP bandwidth can be increased from 13.6% to 25%, and the directivity is enhanced by 2dB in the frequency band when the eccentricity of the cross-section is 0.94.