A high gain OAM antenna based on splitting spiral phase plate for C band

In this paper, a high gain orbital angular momentum (OAM) antenna operating at C band is presented. High gain OAM antenna consists of Chebyshev synthesis antenna array loading with Fabry-Perot cavity which is designed to enhance gain and decrease side-lobe, and the splitting spiral phase plate (SPP) aiming to generate an OAM beam with mode l=±2. The OAM antenna achieves a directivity of 16.4 dBi in E planes, and an impedance bandwidth of 44.2% with SWR≤2 from 5.9GHz to 8.1GHz. The side-lobe level of antenna is −19dB. Compared with other multimode SPP antenna, the demonstrated antenna not only has higher gain and wider bandwidth but also possesses the lower side-lobe level characteristics.