In this paper, we present a Rotman lens-fed Fabry-Perot resonator antennas (FPRA) for generating multi-mode OAM beams with low beam divergence. The Rotman lens works as a beamforming network in the FPRA for the multi-mode OAM operation, significantly simplifying the feed network of the antenna array. The partially reflecting metasurfaces (PRMS) composed of honeycomb complementary hexagonal patches and apertures are designed to construct the Fabry-Perot resonant cavity and enhance the directivity and meliorate the beam orientation of the generated OAM beam. The simulated and measured results verify the effectiveness of the proposed FPRA.
