Tensor Holographic Impedance Coding Metasurface for Millimeter-Wave Circular Airy OAM Multibeams Generation

In this paper, a tensor holographic impedance coding (THIC) metasurface (MS) with optimized coding scheme is proposed. The size is 20λ
0
× 20λ
0
× 0.08λ
0
, λ
0
is the wavelength at 30GHz. The proposed unit has two metal layers: a circular patch with three parallel slots and a ground, which are in each side of F4B substrate. Then left hand circular polarized (LHCP) dual circular Airy orbital angular momentum (OAM) beams with mode l = 0, 1 are generated by the proposed THICMS with high conversion efficiency 43.6%. The ratio of non-diffraction distance to MS aperture is 3.42, and the developed circular OAM beams has Potential applications in near-field imaging, medical treatment, and Wireless energy transmission. In addition, the proposed coding scheme and unit can be used to design other high performance multifunction MS.