Generating Multi-Mode OAMs with Broadened Common Bandwidth Based on PIN Diodes-Loaded Archimedean Spiral Antenna

This paper proposes an Archimedean planar spiral antenna with PIN diodes loaded on the surface to generate multi-mode vortex electromagnetic (EM) waves. Due to the contributions of PIN diodes, the common bandwidth of different orbital angular momentum (OAM) modes is broadened. The simulation results show that the proposed antenna can generate vortex EM waves carrying four OAM modes with the common bandwidth of 1.8 GHz, which is of great significance for OAM applications.