CN-119315279-B - Super-surface-based high-order mode vortex electromagnetic wave generation structure

CN119315279BCN 119315279 BCN119315279 BCN 119315279BCN-119315279-B

Abstract

The invention discloses a high-order vortex electromagnetic wave generating structure based on a super surface, which comprises the super surface, wherein the super surface comprises a plurality of cell structures, each cell structure comprises a multi-layer plate-shaped structure, a first layer of the multi-layer plate-shaped structure is a metal patch layer, a second layer of the multi-layer plate-shaped structure is a dielectric material layer, a third layer of the multi-layer plate-shaped structure is a metal patch layer, a fourth layer of the multi-layer plate-shaped structure is a dielectric material layer, and a fifth layer of the multi-layer plate-shaped structure is a metal floor layer, the metal patch layer of the first layer comprises a square split ring unit, and the metal patch layer of the third layer comprises a crisscross unit. The high-modulus vortex beam can be flexibly adjusted through structures such as a super surface and the like, so that multi-direction and multi-angle beam control is realized, and the method is suitable for a complex wireless communication environment. Besides wireless communication, the generation and control of the high-modulus vortex wave also has a huge application prospect in the fields of radar, imaging and the like, and the resolution and the detection capability of the system can be improved.

Inventors

WU TONG
ZHOU YIJIANG
SHENG QINGHONG
ZHANG YU
WANG JIMING
LU YUANGANG
HE CHONGJUN

Assignees

南京航空航天大学

Dates

Publication Date: 20260508
Application Date: 20241015

Claims (2)

1. The high-order mode vortex electromagnetic wave generating structure based on the super surface is characterized by comprising the super surface, wherein the super surface comprises a plurality of cell structures, each cell structure comprises a plurality of layers of plate-shaped structures, a first layer of the multi-layer plate-shaped structure is a metal patch layer, a second layer of the multi-layer plate-shaped structure is a dielectric material layer, a third layer of the multi-layer plate-shaped structure is a metal patch layer, a fourth layer of the multi-layer plate-shaped structure is a dielectric material layer, and a fifth layer of the multi-layer plate-shaped structure is a metal floor layer; the metal patch layer of the first layer comprises a square split ring unit which is used for generating circularly polarized vortex electromagnetic waves; The dielectric layer material of the second layer and the fourth layer is F4B with phase dielectric constant 2.65, And a tangent loss angle of 0.0009; the metal patch layer of the third layer comprises a crisscross unit and is used for generating linearly polarized vortex electromagnetic waves under the online polarization condition; the design method of the structure comprises the following steps: S1, constructing cell parameters, optimizing the size parameters of a square split ring unit structure by taking the rotation angle and the slotting width of a slotting strip of the square split ring unit in a cell structure as optimization variables according to the requirements of the reflected vortex wave on cell amplitude and phase, forming a square split ring by forming slots with the slot width g on a square resonance ring by slotting strips after rotating alpha, wherein the rotation angle takes a value from 0 to 180 degrees at intervals of 5 degrees, and the different rotation angles respectively correspond to the slotting widths required by fixed resonance frequency points to obtain 37 basic states; 4 basic states of the crisscross unit, and four cell patterns are constructed according to parameters of the four states, wherein the parameters are respectively as follows: ; ; ; ; Wherein the method comprises the steps of Is the arm length of the metal strip in the horizontal direction, Is the width of the metal strip in the horizontal direction, Is the arm length of the metal strip in the vertical direction, The width of the metal strip in the vertical direction; S2, deducing an electric field expression of the vortex wave propagating along the transmission direction of the electromagnetic wave according to a Helmholtz equation of a free space: Where i is the imaginary unit, For the azimuth angle in the cylindrical coordinate system, For the longitudinal wave number, For the amplitude of the beam, Is the height in the cylindrical coordinate system, Radial distance in a cylindrical coordinate system; The topology number, i.e., the number of OAM modes; The theoretical phase distribution of the vortex wave carrying OAM on the transverse plane is that Wherein As the number of topologies to be considered, Is angular, i is an imaginary symbol, and is at the position of the coordinate The vortex phase required to be introduced by the super surface cell is: because the incident vertical polarization and horizontal polarization are spherical waves, the cells in different positions need to compensate the phase of the spherical waves, and the phase center of a selected feed source is in a relative position in space relative to the center point of the super-surface The coordinates on the super surface are The relative positions of the cells are The distance from the feed source phase center to each cell is At the coordinate position of The feed source compensation phase required to be introduced by the super-surface cell is as follows: Where k is the wavenumber in vacuo at the center frequency point, The wavelength corresponds to the center frequency; The required phase compensation of the hypersurface for the complete linear polarization is then for each cell of the hypersurface: S3, compensating phase by utilizing super surface in MATLAB Calculating theoretical super-surface distribution, arranging a crisscross unit by using 2-bit codes, arranging square split rings by using PB phase rotation units in an angle mode, performing simulation modeling by using CST full-wave simulation software, performing parameter scanning on parameter variables of cells in the step S1 by using a full-wave numerical simulation mode, and compensating for the phases Searching a corresponding parameter value in the parameter scanning result by the calculated parameters corresponding to each cell to obtain a parameter setting value of the cell; and S4, obtaining a parameter set value of each cell in the super-surface array according to MATLAB, and modeling the super-surface array by using CST software.
2. The super-surface based high-order mode vortex electromagnetic wave generating structure according to claim 1, wherein the unit cycle of the unit cell = The thickness of the dielectric material layer of the second layer is=1 mm, and the thickness of the dielectric material layer of the fourth layer is h=2 mm.

Description

Super-surface-based high-order mode vortex electromagnetic wave generation structure Technical Field The invention belongs to the technical field of artificial electromagnetic materials, and particularly relates to a high-order mode vortex electromagnetic wave generation structure based on a super surface. Background With the rapid update iteration of wireless communication technology, conventional channel capacity boosting techniques face significant challenges. In the microwave millimeter wave band, earlier methods for realizing vortex waves have a spiral phase plate, a circular antenna array and the like, and have larger limitations in the aspects of manufacturing process and working bandwidth. In recent years, a super-surface structure is used to realize the generation of vortex waves, the capability of modulating the wave front of electromagnetic waves and the low-profile structure thereof have remarkable application prospect, but the problem related to the generation of high-order OAM vortex waves by using the super-surface is still considered as a field which is being explored initially. Research on multifunctional vortex waves based on super surfaces is also mostly staying in generating dual polarized vortex waves. The creation of high-mode OAM vortex waves using a super surface presents the problem of undesirable side lobes between the two radiated peaks of the OAM vortex wave. While the radiation efficiency and mode purity of the OAM vortex in the high mode may be reduced. In summary, a structural combination and space allocation method is needed to be found to design a super surface which is favorable for generating high-order mode vortex electromagnetic waves and can realize free independent regulation and control of the phases of a plurality of polarized electromagnetic waves under one unit aperture. The prior patent CN115173071A provides a vortex wave generating structure and a design method based on a multifunctional shared aperture super surface, and skillfully designs a single-layer multi-polarization multi-band reflection super surface with shared aperture by a structure combination and space distribution method, so that the independent regulation and control of the phases of different polarized reflection waves working in different wide frequency bands are realized, but the mode number of the generated vortex wave beams is lower. Disclosure of Invention The invention aims to solve the problem that the mode number of vortex electromagnetic wave generated by using a super surface is low at present. In order to achieve the above object, the present invention provides a high-order mode vortex electromagnetic wave generating structure based on a super surface, the high-order mode vortex electromagnetic wave generating structure comprises a super surface, the super surface comprises a plurality of cell structures, each cell structure comprises a multi-layer plate structure, the first layer of the multi-layer plate structure is a metal patch layer, the second layer is a dielectric material layer, the third layer is a metal patch layer, the fourth layer is a dielectric material layer, and the fifth layer is a metal floor layer; the metal patch layer of the first layer comprises a square split ring unit which is used for generating circularly polarized vortex electromagnetic waves; The dielectric layer material of the second layer and the fourth layer is F4B with phase dielectric constant 2.65, And a tangent loss angle of 0.0009; The metal patch layer of the third layer comprises a crisscross unit for generating linearly polarized vortex electromagnetic waves under the condition of on-line polarization. Further, the unit cycle of the cells=The dielectric material layer thickness of the second layer h=1 mm, the dielectric material layer thickness of the fourth layer h=2 mm, =10 mm. The design method of the super-surface high-order mode vortex electromagnetic wave comprises the following steps: S1, constructing cell parameters, optimizing the size parameters of a square split ring unit structure by taking the rotation angle and the slotting width of a slotting strip of the square split ring unit in a cell structure as optimization variables according to the requirements of the reflected vortex wave on cell amplitude and phase, forming a square split ring by forming slots with the slot width g on a square resonance ring by slotting strips after rotating alpha, wherein the rotation angle takes a value from 0 to 180 degrees at intervals of 5 degrees, and the different rotation angles respectively correspond to the slotting widths required by fixed resonance frequency points to obtain 37 basic states; 4 basic states of the crisscross unit, and four cell patterns are constructed according to parameters of the four states, wherein the parameters are respectively as follows: ; ; ; ; Wherein the method comprises the steps of Is the arm length of the metal strip in the horizontal direction,Is the width of th