Study of a tri-filar hemispherical helical antenna on a hemisphere of dielectric resonator on a large ground plane

Abstract

There are many types of helical antennas, namely the cylindrical helical antenna, the quadrifilar helix antenna, the spherical helical antenna, etc. In general, each type of antenna has its own characteristic. This project will study a Tri-filar hemispherical helical antenna which has the surface of a DR hemisphere with a large ground plane. The antenna is better than the other antenna of being able to stand steadily in the vertical position. Furthermore, this antenna has ~ 6.5 dBi antenna gain, around 20% bandwidth, large main lobe and less side lodes. The DR hemispherical helical antenna designed with a small size which can be conveniently installed on mobile station for satellite communication. One of disadvantage found on this type of antenna is that it requires the complicated feed method (3-way Wilkinson power divider).