Encoded and Nested Tensor Holographic Impedance Metasurface Design for Millimeter-Wave Airy OAM Multibeams Generation

In this paper, rotation angle of the slot of the single layer tensor holographic impedance metasurface (THIMS) units is quantized and encoded by 1 bit, and the high-performance millimeter-wave circularly polarized circular Airy orbital angular momentum(OAM) beams are generated. Then the structural parameter distribution of the two beams with different directions are respectively nested and reorganized to form a new array, which can generate dual beam. And the circular Airy OAM beams have 68.5λ0 long non-diffraction distance and obvious auto-focusing properties. The design method can effectively reduce the unnecessary energy and make the energy at the focus more concentrated in near field for circular Airy OAM multibeams, which has reference value for the application of wireless energy transmission, near-field imaging and other near-field scenarios.