Improvement on the multi-mode beams divergence of oam array by using fabry-perot cavity

The multi-mode OAM beams generated by a circular phased antenna array are always in divergent directions, which restrict the practical application. To relieve this drawback, the Fabry-Perot (FP) cavity is employed to meliorate the beam orientation, and enhance the directivity of the OAM array. The Fabry-Perot cavity consists of a ground plane, an air cavity and a partially reflecting surface (PRS) composed of periodic complementary circular patches and apertures. The simulated results verify the effectiveness of the proposed design.