A Broadband Printed Quadrifilar Helical Antenna With a Novel Compact Broadband Feeding Network

Abstract—A broadband printed quadrifilar helical antenna (BPQHA) integrated with a broadband feeding network for satellite communications is proposed. Using a multiple arm technique, satisfactory antenna characteristics over a wide bandwidth are realized. To feed the antenna, a novel compact broadband feeding network composed of a frequency independent 180 ◦ out-of-phase power divider, two Wilkinson power dividers and two broadband 90 ◦ phase shifters is designed. The measured boresight gain remains positive with a reflection coefficient lower than −11 dB over a bandwidth of approximately 26%. The axial ratio is below 1.7 dB and the half-power beamwidth is more than 120 ◦ over the same bandwidth. Details of the proposed antenna design are provided and discussed, as well as the experimental results. 1.