A decoupled designed four-function metasurface structure

Abstract

The present application relates to the technical field of artificial electromagnetic material, and particularly relates to a four-function super surface structure of decoupling design. The four-function super surface structure comprises an MxM array structure formed by super surface units with different structural parameters arranged at equal intervals in a plane, wherein the super surface unit is formed by alternately stacking two layers of function control units and two layers of dielectric substrates; the two layers of function control units comprise a first function control unit and a second function control unit; the first function control unit is formed by an n1x n1 array structure arranged in an umbrella shape and is used for regulating and controlling the reflection phase under high-frequency orthogonal circular polarization incidence; and the second function control unit is formed by an n2x n2 array structure arranged in a cross shape and is used for regulating and controlling the reflection phase under low-frequency orthogonal linear polarization incidence.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of artificial electromagnetic materials, and particularly relates to a four-function super surface structure of decoupling design. BACKGROUND

[0002] An electromagnetic super surface, as a two-dimensional metamaterial, is composed of sub-wavelength scatterer units arranged on a two-dimensional plane, and a series of artificial composite structures with unique electromagnetic properties are realized through specific arrangement of the sub-wavelength scatterer units, so that the electromagnetic super surface has high freedom in electromagnetic control.

[0003] In the face of the increasing requirements of information communication systems on data storage capacity and information processing speed, electromagnetic integration plays an increasingly important role, which leads to the trend of multi-scene application of equipment. Among them, the super surface composed of periodic or quasi-periodic microstructures can be characterized by effective uniform surface material parameters, which can be designed to control electromagnetic waves. And these parameters can be designed through super surface details (including structure and arrangement), thereby greatly improving the powerful control ability of the super surface on electromagnetic waves, for example, the customizability of super surface details (including structure and arrangement) improves the modulation freedom of amplitude, phase, polarization, wave front and other electromagnetic properties. As a result, the wave manipulation ability of the super surface has been widely used in the fields of perfect absorption, abnormal deflection, polarization conversion and wave front control, and has further advantages in application compared with traditional super surfaces.

[0004] The phase modulation of the super surface is different from the phase modulation generated by the traditional electromagnetic wave propagating in the medium. The super surface mainly relies on resonance to suddenly change the phase on the interface, which can minimize the volume and cost. Specifically, the super surface has multiple phase modulation mechanisms, for example, the phase modulation of the super surface can modulate the phase response by changing the medium size, geometric position, medium thickness and relative position, and different phase modulation theories lay the foundation for functional integration. Multi-functional integration can be customized through multiplexing of angular momentum, polarization, wavelength and angle. However, the increase of functional integration degree means the increase of super surface design complexity, which undoubtedly causes the difficulty of super surface design. In addition, there is a problem of mutual influence of parameters in the process of multi-functional surface design, for example, when two different structure functional units are stacked together, there is often mutual interference. SUMMARY

[0005] To solve the problems of parameter interaction and high design complexity in the design of the existing multifunctional metasurface, the application aims to provide a four-function metasurface structure designed by decoupling, which can effectively reduce the design complexity by designing independent parameters to regulate electromagnetic response, solve the problems of parameter interaction and high design complexity in the design of the existing multifunctional metasurface, and further regulate the function of the metasurface by designing the equivalent parameters of the unit structure, which has certain research value in the functional design of the metasurface.

[0006] To achieve the above-mentioned purpose, the technical scheme of the application is as follows.

[0007] A four-function metasurface structure designed by decoupling, comprising an MxM array structure composed of metasurface units with different structural parameters arranged at equal intervals in a plane, wherein the metasurface unit is composed of two layers of function control units and two layers of dielectric substrates stacked alternately.

[0008] The first function control unit is an n1x n1 array structure composed of umbrella-shaped structures, which is used to regulate the reflection phase under high-frequency orthogonal circular polarization incidence.

[0009] The second function control unit is an n2x n2 array structure composed of cross-shaped structures, which is used to regulate the reflection phase under low-frequency orthogonal linear polarization incidence.

[0010] Further, the gap between two adjacent umbrella-shaped structures is equal; the gap between two adjacent cross-shaped structures is equal.

[0011] Further, n1 is an even number greater than or equal to 2; n2 is an integer greater than or equal to 1, and n1 is not equal to n2.

[0012] Further, the umbrella-shaped structure comprises:

[0013] The first arc arm regulates the reflection phase of the left-handed circularly polarized wave by changing the curvature of the first arc arm to form a focus.

[0014] The second arc arm regulates the reflection phase of the right-handed circularly polarized wave by changing the curvature of the second arc arm to form a hologram.

[0015] The central axis is connected to the first arc arm and the second arc arm at one end, respectively.

[0016] Further, the cross-shaped structure comprises:

[0017] The X-axis regulates the reflection phase of the x-polarized linearly polarized wave by changing the length of the X-axis in the x-direction to form scattering.

[0018] The Y-axis is used to control the reflection phase of the y-polarized linearly polarized wave by changing the length of the Y-axis in the y direction, so as to form an abnormal reflection.

[0019] The X-axis and the Y-axis are perpendicular to each other.

[0020] Further, the material of the umbrella-shaped structure and the cross-shaped structure is metal.

[0021] Further, the complex permittivity of the dielectric substrate is 2.65 (1+0.001j).

[0022] Further, the thickness of the dielectric substrate is 1.5-3mm.

[0023] Further, the plane is a metal back plate.

[0024] The beneficial effects of the present application are:

[0025] 1. The present application realizes independent control of high-frequency orthogonal circularly polarized waves through an umbrella-shaped structure, and realizes independent control of low-frequency orthogonal linear polarization through a cross-shaped structure. The design problem of a multifunctional metasurface is solved, and the reflection phases under x linear polarization, y linear polarization, left-handed circular polarization and right-handed circular polarization are independently controlled through four independent parameters, and scattering, deflection, focusing and holography are designed under the four polarizations, and integrated in the same metasurface aperture. A method for rapid design of multifunctional metasurfaces is constructed by designing the relationship between the phase and the structure. The overall structure has certain stability, and the architecture is simple, facilitating batch processing and application.

[0026] 2. The present application aims to realize the simplification of the design of the metasurface by designing the mutual independence of the structural parameters of the metasurface. Four reflection phases are corresponded to four independent structural parameters through decoupling design, and the reflection phases under four different polarizations are designed respectively, so as to realize the design of the four-function metasurface structure based on decoupling design. The whole sample can be quickly processed using PCB technology, the design structure is simple, and has strong practicability. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a schematic diagram of the decoupling design four-function metasurface structure provided by the embodiment of the present application. In the figure, 1 is an umbrella-shaped structure, 2 is a dielectric substrate, 3 is a cross-shaped structure, and 4 is a metal back plate.

[0028] Figure 2 is a schematic diagram of a metasurface unit. (A) is the structure and parameters of the metasurface unit, (B) is the structure and parameters of the cross-shaped structure, and (C) is the structure and parameters of the umbrella-shaped structure.

[0029] Figure 3 is l xVariation on phase influence schematic diagram.

[0030] Figure 4 is a L Variation on phase influence schematic diagram.

[0031] Figure 5 is a four-function metasurface structure provided by the decoupling design of embodiment 1, which shows scattering (A), deflection (B), focusing (C), and holographic (D) functions under different polarized wave incidence. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of the present application clearer, the following will further describe the present application in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0033] Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0034] Please refer to Figure 1 A four-function metasurface structure of decoupling design comprises an MxM array structure composed of metasurface units with different structural parameters arranged at equal intervals in a plane, and the plane is a metal back plate 4, which is a metal reflection plate for realizing a reflection-type electromagnetic metasurface. The metasurface unit is composed of two layers of functional control units and two layers of dielectric substrates 2 alternately stacked.

[0035] Please refer to Figures 1 to 2 The two layers of functional control units comprise a first functional control unit and a second functional control unit. The first functional control unit is an n1x n1 array structure composed of umbrella-shaped structures 1, which is used to control the reflection phase under high-frequency orthogonal circular polarization incidence; and the second functional control unit is an n2x n2 array structure composed of cross-shaped structures 3, which is used to control the reflection phase under low-frequency orthogonal linear polarization incidence. Wherein, n1 is an even number ≥ 2; n2 is an integer ≥ 1, and n1≠ n2. For example, n1 = 2x n2. The gaps between adjacent two umbrella-shaped structures 1 are equal; the gaps between adjacent two cross-shaped structures 3 are equal. The materials of the umbrella-shaped structures 1 and the cross-shaped structures 3 are both metal, for example, copper. The dielectric substrate 2 is F4B, the complex permittivity of F4B is 2.65 (1+0.001j), and the thickness of the dielectric substrate 2 is 1.5-3 mm.

[0036] Please refer to Figure 2, the umbrella-shaped structure 1 comprises: a first arc arm, a second arc arm and a middle shaft; one end of the middle shaft is connected with the first arc arm and the second arc arm respectively. The reflection phase of the left-handed circularly polarized wave is regulated by changing the arc of the first arc arm to form focusing; the reflection phase of the right-handed circularly polarized wave is regulated by changing the arc of the second arc arm to form a hologram.

[0037] Please refer to Figure 2 , the cross-shaped structure 3 comprises: an X-axis and a Y-axis, the X-axis and the Y-axis are connected perpendicularly. The reflection phase of the x-polarized linearly polarized wave is regulated by changing the length of the X-axis in the x direction to form scattering; the reflection phase of the y-polarized linearly polarized wave is regulated by changing the length of the Y-axis in the y direction to form abnormal reflection.

[0038] In order to realize the four-function metasurface structure based on decoupling design, the umbrella-shaped structure, the cross-shaped structure, the dielectric substrate, the metal back plate and the like are used to design a layered structure to realize independent regulation of four different phase responses. The reflection phases of the left-handed circularly polarized wave and the right-handed circularly polarized wave under 16GHz incidence can be independently regulated by adjusting the parameters of the arc of the umbrella-shaped structure. The reflection phases of the x-polarized linearly polarized wave and the y-polarized linearly polarized wave under 9GHz incidence can be independently regulated by adjusting the line lengths of the x and y directions of the cross-shaped structure. Specifically, the scattering function is designed under x-polarized incidence. The abnormal reflection function is designed under y-polarized incidence. The focusing function is designed under left-handed circularly polarized incidence. The hologram function is designed under right-handed circularly polarized incidence. The dielectric substrate 2 is used to provide thickness resonance to meet the resonance phase requirement. The metal back plate 4 is used to realize the reflection-type electromagnetic super surface.

[0039] The four-function metasurface structure based on decoupling design is described in detail as follows.

[0040] Embodiment 1

[0041] In order to realize the four-function metasurface structure based on decoupling design, the umbrella-shaped structure, the cross-shaped structure, the dielectric substrate, the metal back plate and the like are used to design a layered structure to realize independent regulation of four different phase responses.

[0042] As Figure 1The four-function metasurface structure of the decoupling design is an MxM array structure composed of metasurface units with different structural parameters arranged equidistantly in the metal back plate 4, and M is an integer greater than or equal to 1. The metasurface unit includes a first function control unit, a second function control unit, and two layers of dielectric substrates 2, and the second function control unit is laid between the two layers of dielectric substrates, and the dielectric substrate at the bottom is fixed with the metal back plate 4. The first function control unit is a 2x2 array structure composed of umbrella-shaped structures 1, and the gap between adjacent two umbrella-shaped structures 1 is equal; the second function control unit is composed of a single cross-shaped structure 3. The materials of the umbrella-shaped structure 1 and the cross-shaped structure 3 are copper materials.

[0043] As Figure 2 , the length p of the metasurface unit is 12 mm. The first function control unit is a high-frequency control layer. In the high-frequency control layer, the umbrella-shaped structure 1 includes a left arc arm, a right arc arm, and a central axis, the radian of the left arc arm is represented by a L , and the radian of the right arc arm is represented by a R ; by changing the radian a L of the left arc arm, the reflection phase of the left-handed circularly polarized wave is regulated to form a focusing function; by changing the radian a R of the right arc arm, the reflection phase of the right-handed circularly polarized wave is regulated to form a hologram function. The central axis is a straight metal line, the length d of the straight metal line is 4 mm, and the width w2 is 0.3 mm.

[0044] The second function control unit is a low-frequency control layer. In the low-frequency control layer, the cross-shaped structure 3 includes an X-axis and a Y-axis, both of which are straight metal lines, and the X-axis and the Y-axis are connected perpendicularly to form an orthogonal metal line; the width w1 of the orthogonal metal line is 0.7 mm. The length of the X-axis in the x direction is defined as l x , and the length of the Y-axis in the y direction is defined as l y . By changing the length l x of the X-axis in the x direction, the reflection phase of the x-polarized linearly polarized wave is regulated to form a scattering function; by changing the length l y of the Y-axis in the y direction, the reflection phase of the y-polarized linearly polarized wave is regulated to form an anomalous reflection function.

[0045] The dielectric substrate 2 is F4B, the complex dielectric constant of F4B is 2.65(1+0.001j), and the thickness h of the dielectric substrate 2 is 1.5 mm.

[0046] Figure 3 The influence of the change of l x on the x-polarized phase response and other parameters can be seen from Figure 3 , and it can be seen that the response of the x-polarized phase is only affected by the change of l x , that is, l xThe phase of the x-polarization is independently controlled. Thus, it is illustrated that the parameters of the cross structure can control the phase of the low-frequency orthogonal linear polarization and cover 0-330 degrees.

[0047] Figure 4 For the alpha L The influence of the change on the phase response of the left-handed circular polarization and other parameters is shown by Figure 4 It can be seen that the left-handed circular polarization wave is only affected by the change of alpha L , that is, alpha L The phase of the left-handed circular polarization wave is independently controlled. Thus, it is illustrated that the parameters of the umbrella structure can control the phase of the high-frequency orthogonal circular polarization and cover 0-360 degrees.

[0048] Figure 5 The schematic diagram of the scattering, deflection, focusing and holographic functions of the decoupling designed four-function metasurface structure provided for the embodiment 1 of the present application under the incidence of different polarized waves.

[0049] In summary, the embodiment of the present application integrates the cross structure and the umbrella structure through the multi-layer superposition method, which can effectively isolate the independent regulation and control of different functional control units on different electromagnetic waves. Since the designed structure has the property of independent regulation and control, that is, there is almost no influence between the parameters, the low-frequency and high-frequency orthogonal polarized waves can be regulated and controlled respectively, so that the four independent functions of scattering, deflection, focusing and holography can be realized at the same time through the super surface.

[0050] The above is only a preferred embodiment of the present application, and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A decoupled four-functional metasurface structure, characterized in that: It consists of metasurface units with different structural parameters arranged at equal intervals in a plane. M × M The array structure comprises two layers of functional control units and two layers of dielectric substrates stacked alternately. The two-layer functional control unit includes: The first functional control unit is composed of an umbrella structure. n 1 × n 1 An array structure is used to control the reflection phase under orthogonal circular polarization incidence; The second functional control unit is composed of a cross structure arrangement n 2 × n 2 An array structure is used to control the reflection phase under orthogonal linear polarization incidence; The umbrella structure includes: a first arc arm, for regulating the reflected phase of the left-hand circularly polarized wave by changing the curvature of the first arc arm to form a focus; a second arc arm, for regulating the reflected phase of the right-hand circularly polarized wave by changing the curvature of the second arc arm to form a hologram; a central axis, one end of which is connected to the first arc arm and the second arc arm respectively; The cross structure comprises: X-axis, by changing the length of the X-axis in the x-direction to adjust the reflection phase of the x-polarized linear polarized wave to form scattering; Y-axis, regulating the reflection phase of the y-polarized linear polarized wave by changing the length of the Y-axis in the y direction to form an abnormal reflection; The X-axis and the Y-axis are perpendicular to each other.

2. The decoupling-designed four-function metasurface structure according to claim 1, characterized in that: The gaps between two adjacent umbrella-shaped structures are equal; the gaps between two adjacent cross structures are equal.

3. The decoupling-designed four-function metasurface structure according to claim 1, characterized in that: n 1 is an even number ≥ 2; n 2 is an integer ≥ 1, and n 1 ≠ n 2 .

4. The decoupling-designed four-function metasurface structure according to claim 1, characterized in that: The umbrella-shaped structure and the cross structure are made of metal.

5. The decoupling-designed four-function metasurface structure according to claim 1, characterized in that: The complex dielectric constant of the dielectric substrate is 2.65(1+0.001j).

6. The decoupling-designed four-function metasurface structure according to claim 1, characterized in that: The thickness of the dielectric substrate is 1.5-3 mm.

7. The decoupled four-function metasurface structure according to claim 1, characterized in that: The plane is a metal back plate.

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