The Basics of Quadrifilar Helix Antennas

With the explosive growth of satellite-based services, the ability to receive or transmit a tight beam of circularly polarized radiation while minimizing unwanted radiation is imperative to maintaining good communication. For such demanding applications, the axial-mode quadrifilar helical antenna provides a high performance and robust antenna platform both in space as well as on the ground.  Furthermore, for portable and handheld radio systems, the quadrifilar helical antenna can be readily miniaturized, providing good quality circular polarization and near hemispherical coverage in the UHF and microwave bands.