| Abstract: | Emission of underwater acoustic orbital angular momentum(OAM) is studied as well as underwater acoustic communications with OAM multiplexing. Theoretical acoustic properties for circular phased array are analyzed based on point source theory. We optimize and design an array prototype based on cymbal transducer. The diameter of array prototype is 180 mm, the number of array elements is 10, and the working frequency is 25 k Hz. It emits acoustic OAM with topological charges-3 to 3. The favorable results provide the theoretical basis for emitting acoustic OAM with different topological charges. We encode on-off states of acoustic OAM with different topological charges according to ASCII code to realize underwater acoustic communications. The transmission results suggest that acoustic OAM with various topological charges have intrinsically orthogonal properties. This research will offer potential applications in underwater acoustic communications. |
