A Novel Dual Circularly-Polarized Waveguide Antenna Array

A novel dual circularly polarized (CP) waveguide slot antenna array is presented. The RHCP and LHCP antenna array share a same aperture and adjacent wall. The radiating element is composed of a pair of tilted slots cut in the narrow walls of a ridge waveguide and a longitudinal slot in bottom of the U-shaped wall, which radiate a couple of orthogonal electromagnetic fields. The quarter of wave length depth of the ridge offers 90° phase difference for the two polarized fields. The difference of the RHCP and LHCP is the longitudinal slot offset. The dual CP antenna array obtains high efficiency and simple structure. A simple planar array is simulated to verify the design.