A design method for structural four-bit binary cross- and co-polarized transmission and reflection energy distribution metasurface

Abstract

The present invention provides a design method for a structural four-bit binary cross and co-polarized transmission and reflection energy distribution metasurface, comprising the following steps: establishing a structural metasurface unit, including top and bottom H-type resonators, an intermediate metal layer, and upper and lower dielectric substrates; the intermediate metal layer includes a cross-shaped opening, and the rotation angle of the H-shaped metal patch and the angle and size of the cross-shaped opening are changed to distribute the energy of cross-polarization transmission, cross-polarization reflection, co-polarization transmission, and co-polarization reflection; the energy distribution is discretized and converted into a four-bit binary form to achieve complete four-bit binary energy distribution. The present invention achieves flexible regulation and design of energy distribution by performing four-bit binary encoding on the cross and co-polarized transmission and reflection energy.

Description

Technical Field

[0001] The present invention relates to the technical field of metasurface devices, and in particular to a design method for a structural four-bit binary cross and co-polarized transmission and reflection energy distribution metasurface. Background Art

[0002] Metasurface is a two-dimensional material composed of artificial structural units at the subwavelength scale. Through the precise design of the unit structure, it can flexibly control the amplitude, phase, polarization and other parameters of electromagnetic waves. Devices based on metasurfaces have the advantages of design flexibility, easy manufacturing, low loss and cost-effectiveness. They show great application potential in wireless communications, wireless energy transmission systems, image formation, information encryption and wave information processing.

[0003] In the research of metasurfaces, energy distribution function is an important direction. However, at present, the distribution function of electromagnetic wave energy of many metasurfaces is concentrated on a single mode (reflection or transmission), and few studies have simultaneously manipulated cross-polarization transmission, cross-polarization reflection, co-polarization transmission, and co-polarization reflection energy. In addition, energy distribution is usually described and controlled by continuous analog quantities, which often requires cumbersome parameter optimization processes in complex scenarios.

[0004] Binary coding is an efficient discretization method. Its core idea is to divide continuous physical quantities into finite states and represent these states with binary numbers. By mapping energy distribution into two states, "0" and "1", the design complexity can be reduced. Summary of the invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide a design method for a structural four-bit binary cross- and co-polarized transmission and reflection energy distribution metasurface in view of the shortcomings of the prior art, so as to solve the current lack of research on electromagnetic wave energy distribution in multiple modes.

[0006] The method of the present invention comprises the following steps:

[0007] Step 1, establishing a metasurface unit, the metasurface unit is composed of a five-layer structure, including a top H-type metal resonator, an upper dielectric substrate, an intermediate metal layer, a lower dielectric substrate, and a bottom H-type metal resonator arranged in sequence from top to bottom; the top H-type metal resonator, the bottom H-type metal resonator and the intermediate metal layer are all metal patches, which are respectively attached to the upper surface of the upper dielectric substrate, the lower surface of the lower dielectric substrate and the upper surface of the lower dielectric substrate; the intermediate metal layer is provided with a cross-shaped opening;

[0008] Step 2, changing the rotation angle of the top H-shaped metal resonator and the bottom H-shaped metal resonator and the rotation angle and size of the cross-shaped opening to distribute the energy of cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection at the same frequency point;

[0009] Step 3, discretize the energy of cross-polarization transmission, cross-polarization reflection, co-polarization transmission, and co-polarization reflection, and regard them as four-bit binary bits from high to low in sequence, so as to realize complete four-bit binary coding at the same frequency point.

[0010] In step 1, the upper dielectric substrate and the lower dielectric substrate are completely the same and have a thickness of 2 mm.

[0011] In step 1, the upper dielectric substrate, the lower dielectric substrate and the middle metal layer are all square, with a side length of 7.25 mm.

[0012] In step 1, the radius of the top H-shaped metal resonator is R=2.9 mm, and two cracks are symmetrically distributed on the left and right. The length of the cracks is 2.72 mm and the width is 2.11 mm.

[0013] In step 1, the top layer H-type metal resonator and the bottom layer H-type metal resonator have the same structure.

[0014] In step 1, the cross-shaped opening of the intermediate metal layer is located at the center of the metal layer.

[0015] In step 1, the materials of the top H-shaped metal resonator, the middle metal layer and the bottom H-shaped metal resonator are all copper.

[0016] In step 2, an angle rotation is performed within the xoy plane of the rectangular coordinate system, and with the y-axis as a reference, the inner angle formed with the symmetry axis of the top H-type metal resonator is set to a rotation angle α, the inner angle formed with the symmetry axis of the bottom H-type metal resonator is set to a rotation angle β, and the inner angle formed with the symmetry axis of the cross-shaped opening of the middle metal layer is set to a rotation angle θ; by adjusting the rotation angles α, β, θ and the size of the cross-shaped opening of the middle metal layer, the energy of cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection is allocated at the same frequency point;

[0017] In step 3, the energy allocation state is mapped to two discrete values ​​of 0 and 1. The four binary bits correspond to the four modes of cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection. The presence of 1 in one or more binary bits indicates that the corresponding one or more polarization modes need to be allocated energy, and 0 indicates that no energy needs to be allocated.

[0018] In step 3, at the same frequency point 16 GHz, the four-bit binary allocation of the cross-polarization transmission and reflection energy is realized: if the cross-polarization transmission energy is 1, the cross-polarization reflection energy is 1, the co-polarization transmission energy is 1, and the co-polarization reflection energy is 1 after discretization, it is represented by the binary number 1111. The "1" is the "1" after energy discretization, which means that energy needs to be allocated to all four polarization states.

[0019] Beneficial effects: The present invention successfully realizes electromagnetic wave energy distribution in four modes: cross-polarization transmission, cross-polarization reflection, co-polarization transmission, and co-polarization reflection. By utilizing a four-bit binary coding design method, the unit can flexibly realize 15 different cross- and co-polarization transmission and reflection energy distribution states, thereby significantly improving the flexibility of energy distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A stereogram of a metasurface designed for the method of the present invention.

[0021] Figure 2 Schematic diagram of the upper dielectric substrate and the top H-type metal resonator.

[0022] Figure 3 Schematic diagram of the intermediate metal layer.

[0023] Figure 4 Schematic diagram of the lower dielectric substrate and the bottom H-type metal resonator.

[0024] Figure 5 Schematic diagram of the status of the metal resonator and the cross-shaped opening in each unit under binary coding.

[0025] Figure 6 Heat map of the transmitted and reflected energy distribution for cross- and co-polarization under binary coding.

[0026] Figure 7 When the binary code is 1011, the transmission and reflection energy distribution curves of cross and co-polarization are shown.

[0027] Figure 8 When the binary code is 1111, the transmission and reflection energy distribution curves of cross and co-polarization are shown.

[0028] Explanation of the reference numerals: 1: top H-type metal resonator; 2: upper dielectric substrate; 3: middle metal layer; 4: lower dielectric substrate; 5: bottom H-type metal resonator. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0030] The embodiment of the present invention provides a design method for a structural four-bit binary cross and co-polarized transmission and reflection energy distribution metasurface, comprising the following steps:

[0031] Step 1: Establish a super surface unit, such as Figure 1 As shown, the metasurface unit is composed of a five-layer structure, including a top H-type metal resonator 1, an upper dielectric substrate 2, an intermediate metal layer 3, a lower dielectric substrate 4, and a bottom H-type metal resonator 5 arranged in sequence from top to bottom; the top H-type metal resonator 1, the bottom H-type metal resonator 5 and the intermediate metal layer 3 are all metal patches, which are respectively attached to the upper surface of the upper dielectric substrate 2, the lower surface of the lower dielectric substrate 4 and the upper surface of the lower dielectric substrate 4; the intermediate metal layer 3 is provided with a cross-shaped opening;

[0032] Step 2, changing the rotation angle of the top H-shaped metal resonator 1 and the bottom H-shaped metal resonator 5 and the angle and size of the cross-shaped opening to distribute the energy of cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection at the same frequency point;

[0033] Step 3, discretize the energy of cross-polarization transmission, cross-polarization reflection, co-polarization transmission, and co-polarization reflection, and regard them as four-bit binary bits from high to low in sequence, so as to realize complete four-bit binary coding at the same frequency point.

[0034] In step 1, the upper dielectric substrate 2 and the lower dielectric substrate 4 are completely identical and have a thickness of 2 mm.

[0035] In step 1, the upper dielectric substrate 2, the lower dielectric substrate 4 and the middle metal layer 3 are all square, with a side length of 7.25 mm.

[0036] In step 1, the radius of the top H-shaped metal resonator 1 is R=2.9 mm, with two cracks symmetrically distributed on the left and right, and the length of the cracks is 2.72 mm and the width is 2.11 mm.

[0037] In step 1, the top layer H-type metal resonator 1 and the bottom layer H-type metal resonator 5 have the same structure.

[0038] In step 1, the cross-shaped opening of the intermediate metal layer 3 is located at the center of the metal layer.

[0039] In step 1, the materials of the top H-type metal resonator 1, the middle metal layer 3 and the bottom H-type metal resonator 5 are all copper.

[0040] In step 2, an angle rotation is performed within the xoy plane of the rectangular coordinate system. Taking the y-axis as a reference, the inner angle formed with the symmetry axis of the top H-type metal resonator 1 is set to a rotation angle α, the inner angle formed with the symmetry axis of the bottom H-type metal resonator 5 is set to a rotation angle β, and the inner angle formed with the symmetry axis of the cross-shaped opening of the intermediate metal layer 3 is set to a rotation angle θ; by adjusting the rotation angles α, β, θ and the size of the cross-shaped opening of the intermediate metal layer 3, the energy of cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection is distributed at the same frequency.

[0041] In step 3, the energy allocation state is mapped to two discrete values ​​of 0 and 1. The four binary bits correspond to the four modes of cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection. The presence of 1 in one or more binary bits indicates that the corresponding one or more polarization modes need to be allocated energy, and 0 indicates that no energy needs to be allocated.

[0042] In step 3, at the same frequency point 16 GHz, four-bit binary allocation of cross-polarization and co-polarization transmission and reflection energy is realized: if the cross-polarization transmission energy is 1, the cross-polarization reflection energy is 1, the co-polarization transmission energy is 1, and the co-polarization reflection energy is 1 after discretization, it is represented as the binary number 1111.

[0043] like Figure 1 As shown, another specific embodiment of the present invention provides a multi-layer metasurface unit that can realize flexible bit-based energy distribution, and the metasurface unit is composed of two layers of square substrates (an upper dielectric substrate 2 and a lower dielectric substrate 4); wherein the dielectric constant of the dielectric substrate is 3.5.

[0044] like Figure 2 As shown, a top-layer H-type metal resonator 1 is arranged above the upper dielectric substrate 2 .

[0045] Figure 3 Schematic diagram of the intermediate metal layer 3. The intermediate metal layer 3 is provided with a cross-shaped opening.

[0046] Figure 4 The bottom dielectric substrate 4 and the bottom H-type metal resonator 5 are arranged on the lower surface of the bottom dielectric substrate 4. The metal material is copper, and its conductivity is 5.8×10 7 S / m.

[0047] like Figure 5As shown, it is a schematic diagram of the state of two metal resonators and cross-shaped openings in each unit under binary coding. The top of each column represents the structure of the top layer of the unit. From bottom to top, each column is the bottom H-type metal resonator 5 and the lower dielectric substrate 4, the middle metal layer 3, and the top H-type metal resonator 1 and the upper dielectric substrate 2 of the unit. From left to right, it is arranged in descending order according to the four-bit binary number, and contains a total of 15 units. The structural state of each unit is determined by its corresponding binary code.

[0048] like Figure 6 As shown, the cross-polarization and co-polarization transmission and reflection energy distribution of different units at a frequency of 16 GHz. Each column in the figure represents an energy distribution state, and there are 15 different state combinations from left to right. The four blocks from top to bottom in each column correspond to the energy distribution of cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection, respectively. This arrangement order corresponds to the arrangement of four-bit binary code from high to low. The depth of color indicates the size of energy distribution, where the darker the color, the higher the distribution energy, and the lighter the color, the lower the distribution energy. Among them, the energy at "0" is not absolute zero, but means that the energy is less than the limit value of 0.1, which reduces energy loss.

[0049] like Figure 7 As shown, it is a curve diagram of the cross-polarization transmission and reflection energy distribution of 15.9 GHz to 16.1 GHz when the binary code is 1011. The code 1011 indicates that the cross-polarization reflection is not allocated energy, and the cross-polarization reflection energy at 16 GHz is less than the limit value of 0.1.

[0050] like Figure 8 As shown, it is the cross-polarization transmission and reflection energy distribution curve of 15.9GHz~16.1GHz when the binary code is 1111. At this time, the cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection at 16GHz are all allocated energy.

[0051] The present invention provides a design method for a structural four-bit binary cross and co-polarized transmission and reflection energy distribution metasurface. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the scope of protection of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A design method for a structural four-bit binary cross and co-polarized transmission and reflection energy distribution metasurface, characterized in that: The following steps are involved: Step 1, establishing a metasurface unit, the metasurface unit consisting of a five-layer structure, including a top H-type metal resonator (1), an upper dielectric substrate (2), an intermediate metal layer (3), a lower dielectric substrate (4), and a bottom H-type metal resonator (5) arranged in sequence from top to bottom; the top H-type metal resonator (1), the bottom H-type metal resonator (5) and the intermediate metal layer (3) are all metal patches, which are respectively attached to the upper surface of the upper dielectric substrate (2), the lower surface of the lower dielectric substrate (4), and the upper surface of the lower dielectric substrate (4); the intermediate metal layer (3) is provided with a cross-shaped opening; Step 2, changing the rotation angle of the top H-shaped metal resonator (1) and the bottom H-shaped metal resonator (5) and the rotation angle and size of the cross-shaped opening to distribute the energy of cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection at the same frequency point; Step 3, discretize the energy of cross-polarization transmission, cross-polarization reflection, co-polarization transmission, and co-polarization reflection, and regard them as four-bit binary bits from high to low in sequence, so as to realize complete four-bit binary coding at the same frequency point.

2. The method according to claim 1, characterized in that In step 1, the upper dielectric substrate (2) and the lower dielectric substrate (4) are completely identical and have a thickness of 2 mm.

3. The method according to claim 2, characterized in that In step 1, the upper dielectric substrate (2), the lower dielectric substrate (4) and the intermediate metal layer (3) are all square, with a side length of 7.25 mm.

4. The method according to claim 3, characterized in that In step 1, the radius of the top H-shaped metal resonator (1) is R=2.9 mm, with two cracks symmetrically distributed on the left and right, and the length of the cracks is 2.72 mm and the width is 2.11 mm.

5. The method according to claim 4, characterized in that In step 1, the top H-type metal resonator (1) and the bottom H-type metal resonator (5) have the same structure.

6. The method according to claim 5, characterized in that In step 1, the cross-shaped opening of the intermediate metal layer (3) is located at the center of the metal layer.

7. The method according to claim 6, characterized in that In step 1, the materials of the top H-shaped metal resonator (1), the middle metal layer (3) and the bottom H-shaped metal resonator (5) are all copper.

8. The method according to claim 7, characterized in that In step 2, an angle rotation is performed within the xoy plane of the rectangular coordinate system. With the y axis as a reference, the internal angle formed with the symmetry axis of the top H-type metal resonator (1) is set as the rotation angle α, the internal angle formed with the symmetry axis of the bottom H-type metal resonator (5) is set as the rotation angle β, and the internal angle formed with the symmetry axis of the cross-shaped opening of the middle metal layer is set as the rotation angle θ; by adjusting the rotation angles α, β, θ and the size of the cross-shaped opening of the middle metal layer (3), the energy of cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection is distributed at the same frequency point.

9. The method according to claim 8, characterized in that In step 3, the energy allocation state is mapped to two discrete values ​​of 0 and 1. The four binary bits correspond to the four modes of cross-polarization transmission, cross-polarization reflection, co-polarization transmission and co-polarization reflection. The presence of 1 in one or more binary bits indicates that the corresponding one or more polarization modes need to be allocated energy, and 0 indicates that no energy needs to be allocated.

10. The method according to claim 9, characterized in that In step 3, at the same frequency point 16 GHz, four-bit binary allocation of cross-polarization and co-polarization transmission and reflection energy is realized: if the cross-polarization transmission energy is 1, the cross-polarization reflection energy is 1, the co-polarization transmission energy is 1, and the co-polarization reflection energy is 1 after discretization, it is represented as the binary number 1111.

Images