Miniaturization Methods of Circularly Polarized Helix Antennas

In this paper, the miniaturization methods of circularly polarized helix antennas are proposed, including folding radiating arms and inserting high permittivity material. Two corresponding helix antennas are designed and fabricated to verify the methods. The axial lengths are effectively reduced by about 55% and 41%, respectively. By applying the feeding networks based on Wilkinson power dividers, the antennas respectively obtain the impedance bandwidths of 22% and 13% with voltage standing wave ratio (VSWR) < 1.5. The measured results agree well with the simulations, indicating the application potential in communication systems.