A Compact OAM Antenna based on Spoof Localized Surface Plasmonic Resonator

In this paper, a compact OAM antenna based on spoof localized surface plasmons (spoof LSPs) is proposed, which can generate vortex beams with multi-order OAM modes with order number l=-3~+3. Radiation patterns and electric field phase distributions demonstrate that these seven OAM modes with mode purity higher than 94% can be generated at 2.471, 3.745, 4.536 and 5.047 GHz, respectively. The antenna has the advantages of compact structure and small electrical size, which can find wide applications in miniaturized OAM communication systems.