Ultra-Wideband Dual-Circularly Polarized Array with Simple Cost-Effective Feeding Network

A dual-circularly polarized hexagonal array operating over multi-octave bandwidth with cost-effective feeding network is presented. A four-arm spiral antenna with two planar Klopfenstein microstrip feeds is used as a unit cell. The 7-element array is fed by two 7-way power dividers and a single 90 degrees hybrid. The used feeding network in conjunction with fundamental properties of a four-arm spiral supports left and right hand circularly polarized operation over more than 3: 1 bandwidth. The performance of the feeding network, frequency and time-domain characteristics of the proposed array are demonstrated through simulation and comprehensive measurements.