A novel dual-band circularly-polarized wide-beam quadrifilar helix antenna

The satellite communication systems and satellite navigation systems usually require the antenna to provide compact size, wide beam, circular polarization and high gain at low elevation. Based on these needs, a new type of dual-band wide beamwidth quadrifilar helix antenna (QHA) is designed. The available dual-band is achieved by putting two similar antenna structures operated at different frequency bands in an inner and outer coaxial way, and fed by a split coax balun. A 90° self-phased structure is formed through the quadrifilar helix characteristic to obtain a wide beam and good circular polarization performance. Experimental results of the fabricated antenna show that, the measured results are consistent with the simulated ones, and the antenna can provide good wide-beam circular polarization characteristics in both frequency bands.