A metasurface unit structure for electromagnetic wave control

Abstract

The present invention relates to a metasurface unit structure for electromagnetic wave control, which belongs to the field of metasurface electromagnetic control technology, and solves the problems of narrow working frequency band, low efficiency and complex control method of existing metasurface unit structure. The metasurface unit structure includes a first conductor layer, a first dielectric layer, a second conductor layer, a second dielectric layer and a third conductor layer arranged in sequence along the incident direction of the electromagnetic wave; the first conductor layer, the second conductor layer and the third conductor layer all include complementary double open ring resonators, and the complementary double open ring resonators include two concentric semi-rings penetrating the conductor layer, and the two concentric semi-rings constitute an open circular ring, and the connection line of the two openings of the open circular ring passes through the center of the circle; the connection line of the two openings of the first conductor layer and the connection line of the two openings of the third conductor layer are perpendicular to each other. The metasurface unit structure can realize the control of the amplitude and phase of the transmitted wave without changing the structure, and has a wide working frequency band and high transmittance.

Description

Technical Field

[0001] The present invention relates to the technical field of supersurface electromagnetic wave regulation, and in particular to a supersurface unit structure for electromagnetic wave regulation. Background Art

[0002] Electromagnetic waves are widely used in many fields such as communication and focusing, so it is very important to flexibly control the amplitude and phase of electromagnetic waves. In recent years, with the development of metasurface and metamaterial technology, the technology of controlling electromagnetic waves by designing some unit structures to build metasurface arrays has attracted much attention. Metasurfaces can generate various beams such as vortex beams, Airy beams, and Bessel beams. The most important thing to achieve beam wavefront restoration by building a metasurface is to design a unit structure with corresponding functions. At present, there are many types of unit structures that can control the amplitude or phase of electromagnetic waves. The most common ones are metal spiral structures, V-shaped structures, open resonant ring structures, and multi-layer unit structures with other shapes in the middle layer of the upper and lower gratings. For various beams, taking the Airy beam as an example, its non-diffraction, self-healing and self-acceleration properties can make it applicable to the field of communication, and can also realize functions such as particle transport and beam focusing. There are many ways to generate Airy beams, such as generating Airy beams based on the principle of Fourier lens phase difference, spatial light modulators, Airy surface plasmons, continuous phase plates, etc. When using Fourier lenses to obtain Airy beams, the installation accuracy of the system is required to be high. The lens group needs to be precisely controlled in experiments and practical applications, which is difficult and difficult to achieve broadband. In order to avoid burning the instrument in the experiment, the spatial light modulator cannot obtain a beam with high power density. The low damage threshold limits the power of the generated Airy beam. The surface plasmon method mainly uses a resonant structure, which cannot obtain Airy beams in a broadband range, and the transmission efficiency is usually relatively low. The continuous phase plate is large and thick, and it is also impossible to achieve broadband, and the non-diffraction effect of the beam is not ideal. There are many types of existing transmission metamaterial structural units, but there are still some disadvantages, such as narrow bandwidth, low efficiency, and complex control methods. For example, the metal spiral structure unit can perform efficient broadband polarization control of circularly polarized electromagnetic waves, and the phase can be controlled using the PB phase method, but this unit structure cannot flexibly control the amplitude, and the metal spiral structure is a three-dimensional structure, which is not conducive to the design of ultra-thin devices. The structural unit itself is relatively complex, the processing cost is high, and the experiment is difficult. The V-type unit structure can achieve phase control of linear polarization waves by changing the angle and arm length, but this unit structure mainly relies on the resonance of the unit structure, so it can only efficiently control electromagnetic waves at one frequency point and cannot achieve broadband functions. The single-layer open resonant ring structure mainly uses the resonance of the unit structure at a certain frequency and also cannot achieve broadband.

[0003] The existing technology mainly has the following defects. First, the existing structure for generating Airy beams has a narrow working frequency band and the efficiency of the generated Airy beams is low. Second, the existing metasurface unit structures for regulating electromagnetic waves all need to change the structural parameters of the unit structure to regulate the phase or amplitude of the electromagnetic waves. The regulation method is complex, the regulation flexibility is low, and the manufacturing cost is increased. Summary of the invention

[0004] In view of the above analysis, the present invention aims to provide a metasurface unit structure for electromagnetic wave regulation, so as to solve the problems of narrow operating frequency band, low efficiency and complex regulation of electromagnetic waves in existing metasurface unit structures.

[0005] On the one hand, the present invention provides a metasurface unit structure for electromagnetic wave regulation;

[0006] The metasurface unit structure comprises a first conductor layer, a first dielectric layer, a second conductor layer, a second dielectric layer and a third conductor layer arranged in sequence along the incident direction of the electromagnetic wave, wherein the first conductor layer, the second conductor layer and the third conductor layer are perfect electrical conductors corresponding to the electromagnetic wave frequency band;

[0007] The first conductor layer, the second conductor layer and the third conductor layer each include a complementary double open ring resonator, wherein the complementary double open ring resonator includes two concentric half rings penetrating the conductor layer, the two concentric half rings constitute an open circular ring, and a line connecting two openings of the open circular ring passes through the center of the circle;

[0008] The connecting line of the two openings of the first conductor layer and the connecting line of the two openings of the third conductor layer are perpendicular to each other.

[0009] Furthermore, the angle between the connecting line of the two openings of the second conductor layer and the connecting line of the two openings of the third conductor layer and the amplitude of the polarization conversion transmission coefficient of the incident x-polarized electromagnetic wave satisfy the following relationship:

[0010] A θ =A 45° |sin2θ|,

[0011] Wherein, θ represents the angle between the connecting line of the two openings of the second conductor layer and the connecting line of the two openings of the third conductor layer, and the value range of θ is [-180°, 180°), A θ A represents the amplitude of the polarization transmission coefficient of the incident electromagnetic wave with x polarization when the angle is θ. 45° It represents the amplitude of the polarization conversion transmission coefficient of the x-polarized incident electromagnetic wave when the angle is 45°.

[0012] Furthermore, when the angle θ is in the range of (0°, 90°) or [-180°, -90°], the phase value of the polarization transmission coefficient of the x-polarized incident electromagnetic wave is a first phase value, and when the angle θ is in the range of [90°, 180°) or (-90°, 0°], the phase value of the polarization transmission coefficient of the x-polarized incident electromagnetic wave is a second phase value, and the phase difference between the first phase value and the second phase value is 180°.

[0013] On the other hand, the present invention provides an Airy beam generator, comprising a two-dimensional array of metasurface unit structures as claimed in any one of claims 1 to 3 and an electromagnetic wave generating device, wherein;

[0014] In the first dimension of the two-dimensional array, the size of the angle between the connecting line of the two openings of the second conductor layer of each supersurface unit structure and the connecting line of the two openings of the third conductor layer corresponds to the aperture amplitude of the Airy beam at the position of the supersurface unit structure; the range of values ​​of the angle between the connecting line of the two openings of the second conductor layer of each supersurface unit structure and the connecting line of the two openings of the third conductor layer corresponds to the aperture phase of the Airy beam at the position of the supersurface unit structure.

[0015] Furthermore, each metasurface unit structure constitutes a lattice of a two-dimensional array with a lattice constant of 10 mm.

[0016] Furthermore, the outer radius of the double open ring resonator is 4.8 mm, the inner radius is 4 mm, the opening width is 0.2 mm, and the thickness of the first conductor layer, the second conductor layer and the third conductor layer are all 0.035 mm.

[0017] Furthermore, the perfect electrical conductor is metal.

[0018] Furthermore, the first dielectric layer and the second dielectric layer are both made of lossless dielectric materials.

[0019] Furthermore, the thickness of the first dielectric layer and the second dielectric layer are both 2 mm.

[0020] Furthermore, the relative bandwidth of the working frequency band of the generator is 25%.

[0021] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0022] 1. The metasurface unit structure proposed in the present invention improves the bandwidth of the working frequency band by using the interlayer coupling design of the three-layer conductor structure. By changing the electrical size of the metasurface unit structure, it can be made to work in the X-band, infrared band, terahertz band and optical frequency band. In addition, by setting the size of the angle between the connection line of the two openings of the second conductor layer and the connection line of the two openings of the third conductor layer, the amplitude of the transmitted electromagnetic wave can be regulated, and the regulation range of the amplitude of the transmitted electromagnetic wave is [0,1]. The range of values ​​of the angle between the lines connecting the two openings of the conductor layer can realize the regulation of the phase of the transmitted electromagnetic wave to 0° or 180°, that is, the phase of the transmitted electromagnetic wave is regulated from 0° to 180°, or from 180° to 0°, without changing the structural dimensions of the metasurface unit structure, and the regulation method is simple; in addition, the metasurface unit structure can not only be used to construct a generator for generating Airy wave beams, but also can be used to construct electromagnetic wave beams with arbitrary amplitude distribution and phase distribution of 0° and 180° in a binary form, such as a zero-order Bessel beam.

[0023] 2. The metasurface unit structure proposed in the present invention has a transmittance of higher than 90% for the received polarized transmitted electromagnetic waves for the linearly polarized electromagnetic waves incident in the x-polarization direction within a wider frequency band. The transmittance for the co-polarized transmitted electromagnetic waves is very low. Therefore, the metasurface structure can be used to obtain transmitted electromagnetic waves with very high polarization purity.

[0024] 3. The Airy beam generator based on the metasurface unit structure proposed by the present invention has a high polarization transmission rate for incident electromagnetic waves in the x-polarization direction for linearly polarized incident electromagnetic waves in the frequency band of 8.7-11.2 GHz, and the obtained Airy beam has high efficiency. In addition, in the Airy beam generator, the sizes of the multiple metasurface unit structures arranged in a two-dimensional array are the same, and only the angle between the connection line of the two openings of the second conductor layer and the connection line of the two openings of the third conductor layer are different, which reduces the manufacturing process of the two-dimensional array and greatly reduces the manufacturing cost.

[0025] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0027] Figure 1 A schematic diagram of a supersurface unit structure according to an embodiment of the present invention;

[0028] Figure 2 Schematic diagram of a curve showing a change in transmission coefficient with the frequency of an incident electromagnetic wave under different polarization conditions in an embodiment of the present invention;

[0029] Figure 3 It is a schematic diagram of a curve showing a change in transmission coefficient corresponding to different angles with the frequency of the incident electromagnetic wave under the condition of x-polarization incident polarization conversion in an embodiment of the present invention;

[0030] Figure 4 It is a schematic diagram of the variation curve of the transmission coefficient corresponding to the incident electromagnetic waves of three different frequencies with the angle under the condition of x-polarization incident polarization conversion in the embodiment of the present invention;

[0031] Figure 5 It is a schematic diagram of the phase variation curve of the transmitted electromagnetic wave corresponding to the incident electromagnetic waves of three different high frequencies with the angle under the condition of x-polarization incident polarization conversion in the embodiment of the present invention;

[0032] Figure 6 is a schematic diagram of an Airy beam generator according to an embodiment of the present invention;

[0033] Figure 7 is a schematic diagram of a cross-sectional view of an Airy beam according to an embodiment of the present invention;

[0034] Figure 8 Schematic diagram of the distribution of the aperture amplitude of the Airy wave beam according to an embodiment of the present invention;

[0035] Fig. 9 Schematic diagram of the aperture and phase distribution of the Airy wave beam according to an embodiment of the present invention;

[0036] Fig.10 This is a schematic diagram of the Airy wave beam obtained by simulation when the frequency of the incident electromagnetic wave is 8.7 GHz according to an embodiment of the present invention;

[0037] Fig.11 This is a schematic diagram of the Airy wave beam obtained by field testing when the frequency of the incident electromagnetic wave in an embodiment of the present invention is 8.7 GHz;

[0038] Fig.12 This is a schematic diagram of the Airy wave beam obtained by simulation when the frequency of the incident electromagnetic wave is 10.1 GHz according to an embodiment of the present invention;

[0039] Fig.13 This is a schematic diagram of the Airy wave beam obtained by field testing when the frequency of the incident electromagnetic wave in an embodiment of the present invention is 10.1 GHz;

[0040] Fig.14This is a schematic diagram of the Airy wave beam obtained by simulation when the frequency of the incident electromagnetic wave is 11.2 GHz according to an embodiment of the present invention;

[0041] Fig.15 This is a schematic diagram of the Airy wave beam obtained by field testing when the frequency of the incident electromagnetic wave is 11.2 GHz according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0043] A specific embodiment of the present invention discloses a metasurface unit structure for electromagnetic wave regulation.

[0044] like Figure 1 As shown, the metasurface unit structure includes a Figure 1 The first conductor layer, the first dielectric layer, the second conductor layer, the second dielectric layer and the third conductor layer are arranged in sequence (in order from top to bottom in the figure), wherein the first conductor layer, the second conductor layer and the third conductor layer are perfect electrical conductors corresponding to the electromagnetic wave frequency band.

[0045] The first conductor layer, the second conductor layer and the third conductor layer each include complementary double split ring resonators (CSRRs), which include two concentric half rings penetrating the conductor layer, the two concentric half rings forming an open circular ring, and a line connecting two openings of the open circular ring passes through the center of the circle.

[0046] The connecting line of the two openings of the first conductor layer and the connecting line of the two openings of the third conductor layer are perpendicular to each other.

[0047] Preferably, the angle between the line connecting the two openings of the second conductor layer and the line connecting the two openings of the third conductor layer and the amplitude of the polarization conversion transmission coefficient of the incident x-polarized electromagnetic wave satisfy the following relationship:

[0048] A θ =A 45° |sin2θ|,

[0049] Wherein, θ represents the angle between the connecting line of the two openings of the second conductor layer and the connecting line of the two openings of the third conductor layer, and the value range of θ is [-180°, 180°), A θ A represents the amplitude of the polarization transmission coefficient of the incident electromagnetic wave with x polarization when the angle is θ. 45° It represents the amplitude of the polarization transmission coefficient of the incident electromagnetic wave with x polarization when the angle is 45°. According to this relationship, the size of the angle in the metasurface unit structure can be set to adjust the amplitude of the transmitted electromagnetic wave.

[0050] from Figure 1 It can be seen from the figure that θ can also be expressed as the angle between the line connecting the two openings of the second conductor layer and the positive direction of the x-axis.

[0051] Preferably, when the angle θ is in the range of (0°, 90°) or [-180°, -90°], the phase value of the polarization transmission coefficient of the x-polarized incident electromagnetic wave is a first phase value, and when the angle θ is in the range of [90°, 180°) or (-90°, 0°], the phase value of the polarization transmission coefficient of the x-polarized incident electromagnetic wave is a second phase value, and the phase difference between the first phase value and the second phase value is 180°.

[0052] The regulating effect of the metasurface unit structure on electromagnetic waves is now better described through the following embodiments.

[0053] In the metasurface unit structure, each double open ring resonator is the same, the outer radius of the double open ring resonator is 4.8mm, the inner radius is 4mm, the opening width is 0.2mm, the thickness of the first conductor layer, the second conductor layer and the third conductor layer are all 0.035mm, the material of the three conductor layers is PEC, the thickness of the first dielectric layer and the second dielectric layer is d=2mm, the dielectric material is a lossless dielectric material, the side length of the dielectric layer and the conductor layer (ie, the lattice constant) is 10mm, and the metasurface structure unit is vertically incident with a linearly polarized electromagnetic wave. Based on the above structural parameter settings, simulation is performed, and the simulation results are as follows:

[0054] Specifically, when the angle between the line connecting the two openings of the second conductor layer and the line connecting the two openings of the third conductor layer is set to 45°, the relationship between the transmission coefficient (i.e., the amplitude of the transmitted electromagnetic wave) and the frequency of the incident electromagnetic wave under different polarization conditions is obtained as follows: Figure 2 When the angle is 135°, 225° or 315°, the relationship between the transmission coefficient and the frequency of the incident electromagnetic wave under different polarization conditions is shown in Figure 2. Figure 2 same.

[0055] The transmission coefficient includes the amplitude information (ie, the amplitude value) of the transmitted electromagnetic wave and the phase information (ie, the phase value) of the transmitted electromagnetic wave.

[0056] Specifically, Figure 2 In, t (x,x) represents the co-polarization transmission coefficient for incident light in the x-polarization direction (i.e. incident light in the polarization direction), t (x,x) The corresponding change curve shows that the transmission coefficient of the transmitted electromagnetic wave in the x-polarization direction obtained for the incident electromagnetic wave changes with the frequency of the incident electromagnetic wave. It can be seen that in the 6-14GHz incident electromagnetic wave frequency band, the maximum transmission coefficient is 0.2.

[0057] t (y,y) represents the co-polarized transmission coefficient for the y-polarized incident direction, t (y,y) The corresponding change curve shows that the transmission coefficient of the incident electromagnetic wave in the y-polarization direction and the corresponding transmission electromagnetic wave in the y-polarization direction change with the frequency of the incident electromagnetic wave. It can be seen that in the 6-14GHz incident electromagnetic wave frequency range, the maximum transmission coefficient is 0.2; Figure 2 It can be seen that t (x,x) ,t (y,y) The two corresponding change curves basically overlap, so it can be concluded that the metasurface unit structure has a very low co-polarization transmission efficiency for linearly polarized incident electromagnetic waves, indicating that the metasurface unit structure basically does not transmit co-polarized transmitted electromagnetic waves.

[0058] t (x,y) represents the polarization-converted transmission coefficient for the y-polarization incident direction, t (x,y) The corresponding change curve shows that the transmission coefficient of the incident electromagnetic wave in the y-polarization direction and the corresponding transmitted electromagnetic wave in the x-polarization direction change with the frequency of the incident electromagnetic wave. It can be seen that in the 8.7-11.2GHz incident electromagnetic wave frequency band, the transmission coefficient is almost 0, indicating that the metasurface unit structure hardly transmits electromagnetic waves that are incident in the y-polarization direction and emitted in the x-polarization direction.

[0059] t (y,x) represents the polarization-converted transmission coefficient for incident light in the x-polarization direction, t (y,x) The corresponding change curve shows that the transmission coefficient of the incident electromagnetic wave in the x-polarization direction and the corresponding transmitted electromagnetic wave in the y-polarization direction change with the frequency of the incident electromagnetic wave. It can be seen that in the 6-14GHz incident electromagnetic wave frequency band, the transmission coefficient can reach above 0.9, indicating that the transmission efficiency of the metasurface unit structure for electromagnetic waves incident in the x-polarization direction and emitted in the y-polarization direction is very high.

[0060] Figure 3 The graph shows the variation of the polarization-converted transmission coefficient corresponding to different angles in the x-polarization direction with the frequency of the incident electromagnetic wave. It can be seen from the graph that in the 8.7-11.2 GHz incident electromagnetic wave frequency band, when the angle is 0°, the transmission coefficient is 0. As θ changes, the amplitude of the transmission coefficient changes according to the law of sin(2θ).

[0061] Figure 4The figure is a schematic diagram of the curves of the change of the polarization transmission coefficient with the angle for the incident electromagnetic waves in the x-polarization direction with three different frequencies of 8.7 GHz, 10.1 GHz and 11.2 GHz. It can be seen from the figure that the three change curves overlap, indicating that when the incident electromagnetic waves in the frequency band range of 8.7-11.2 GHz hit the metasurface unit structure, the transmission coefficient changes with the angle in the same way, that is, the working frequency band of the metasurface unit structure is 8.7-11.2 GHz.

[0062] Figure 5 The diagram is a schematic diagram of the phase variation curve of the polarization transmission coefficient of the incident electromagnetic wave in the x-polarization direction at three different high frequencies of 8.7 GHz, 10.1 GHz and 11.2 GHz. It can be seen from the figure that 0° is the jump point of the phase of the transmitted electromagnetic wave. For any of the three frequencies, the phase of the transmitted electromagnetic wave when the angle is in the range of (-90°, 0°] is π different from the phase of the transmitted electromagnetic wave when the angle is in the range of (0°, 90°). In practical applications, according to the above characteristics of the metasurface structure, the angle can be selected in the range of [-45°, 45°] to meet the independent and flexible regulation of the phase and amplitude of the transmitted electromagnetic wave.

[0063] Another embodiment of the present invention provides an Airy beam generator, such as Figure 6 As shown, the two-dimensional array and electromagnetic wave generating device composed of the aforementioned metasurface unit structure also include a probe, wherein the electromagnetic wave generating device includes a network analyzer and a transmitting horn, the network analyzer is communicatively connected to the transmitting horn, and is used to send a control signal to the transmitting horn to control the transmitting horn to transmit electromagnetic waves to the two-dimensional array, and the probe is used to detect the electric field intensity of the transmitted electromagnetic wave (i.e., Airy wave beam) generated by the two-dimensional array. The network analyzer is communicatively connected to the probe, and is used to receive and process the signal detected by the probe. Exemplarily, a network analyzer of model PNA-X5242A can be selected.

[0064] Specifically, the Airy beam profile is as follows: Figure 7 As shown. In the first dimension of the two-dimensional array, the angle between the connecting line of the two openings of the second conductor layer of each metasurface unit structure and the connecting line of the two openings of the third conductor layer corresponds to the aperture amplitude of the Airy beam at the position of the metasurface unit structure, wherein the aperture amplitude distribution diagram of the Airy beam is shown as Figure 8 As shown in the first dimension, the size of the angle in each super surface unit structure is Figure 8The selected dots can reflect the distribution law of the aperture amplitude of the Airy beam as a whole; the value range of the angle between the connecting line of the two openings of the second conductor layer of each metasurface unit structure and the connecting line of the two openings of the third conductor layer corresponds to the aperture phase of the Airy beam at the position of the metasurface unit structure, wherein the aperture phase distribution of the Airy beam is as follows: Fig. 9 As shown, in the first dimension, the value range of each angle is Fig. 9 The selected dot corresponds to the phase indicated by the dot, and the different value ranges of the angle can meet the requirements of 0° or 180° phase of the Airy beam at any amplitude. Specifically, Figure 8 , Fig. 9 The positions of the dots selected in Figure 7 Consistent.

[0065] The beneficial effects of the Airy beam generator proposed by the present invention are better explained through the following embodiments.

[0066] Specifically, each metasurface unit structure in the two-dimensional array structure constitutes a lattice of the two-dimensional array, the lattice constant is 10 mm, and the allowable error of the lattice constant is 5%, that is, the lattice constant fluctuates within the range of [9.5 mm, 10.5 mm]. The corresponding Airy wave beams can meet the requirements. The outer radius of the double open ring resonator is 4.8 mm, the inner radius is 4 mm, and the opening width is 0.2 mm. The thickness of the first conductor layer, the second conductor layer and the third conductor layer are all 0.035 mm. The materials of the first dielectric layer and the second dielectric layer are both lossless dielectric materials. By way of example, low-loss F4B265 can also be selected, with a dielectric constant of 2.65 and a loss tangent of 0.0017.

[0067] The thickness of the first dielectric layer and the second dielectric layer are both 2 mm. Simulation and field tests are performed based on the above parameters. When performing simulation, the conductor layer is set to a perfect electrical conductor, and when performing field tests, the conductor layer is made of metal copper. The specific simulation and field test results are as follows:

[0068] Fig.10 The schematic diagram of the Airy wave beam obtained by simulation is shown when the frequency of the incident electromagnetic wave is 8.7 GHz. Fig.11 A schematic diagram of the Airy wave beam obtained from field testing when the incident electromagnetic wave frequency is 8.7 GHz is shown. Fig.12 , Fig.13 The schematic diagrams of the Airy wave beam obtained by simulation and field test are shown respectively when the frequency of the incident electromagnetic wave is 10.1 GHz; Fig.14 , Fig.15The schematic diagrams of the Airy wave beams obtained by simulation and field tests when the incident electromagnetic wave frequency is 11.2 GHz are shown respectively. It can be seen that in the frequency band of 8.7-11.2 GHz, when electromagnetic waves of different frequencies are incident, the Airy wave beams obtained by simulation and field tests are basically consistent, and both have good non-diffraction characteristics and self-acceleration characteristics. Therefore, the relative bandwidth of the working frequency band of the Airy wave beam generator is 25%, that is, the working bandwidth is 8.7-11.2 GHz.

[0069] Compared with the prior art, the metasurface unit structure for regulating electromagnetic waves proposed in the present invention improves the bandwidth of the working frequency band by using the interlayer coupling design of the three-layer conductor structure. By changing the electrical size of the metasurface unit structure, it can be made to work in the X-band, infrared band, terahertz band and optical frequency band. In addition, by setting the size of the angle between the connection line of the two openings of the second conductor layer and the connection line of the two openings of the third conductor layer, the amplitude of the transmitted electromagnetic wave can be regulated, and the regulation range of the amplitude of the transmitted electromagnetic wave is [0,1]. By setting the two openings of the second conductor layer The value range of the angle between the connecting line of the first conductor layer and the connecting line of the two openings of the third conductor layer can realize the regulation of the phase of the transmitted electromagnetic wave from 0° to 180°, that is, the phase of the transmitted electromagnetic wave is regulated from 0° to 180°, or from 180° to 0°, without changing the structural size of the metasurface unit structure, and the regulation method is simple; in addition, the metasurface unit structure can not only be used to construct a generator for generating Airy wave beams, but also can be used to construct electromagnetic wave beams with arbitrary amplitude distribution forms and phase distributions of 0° and 180° in a binary form, such as a zero-order Bessel beam. Secondly, the metasurface unit structure proposed in the present invention has a transmittance of the received polarized transmitted electromagnetic wave higher than 90% for the linearly polarized electromagnetic wave incident in the x-polarization direction within a wider frequency band, and the relative frequency band is wide, and the transmittance to the same polarized transmitted electromagnetic wave is very low, so the use of the metasurface structure can obtain a transmitted electromagnetic wave with very high polarization purity. In addition, the Airy beam generator based on the metasurface unit structure proposed by the present invention has a high polarization transmission rate for incident electromagnetic waves in the x-polarization direction for linearly polarized incident electromagnetic waves in the frequency band of 8.7-11.2 GHz, and the obtained Airy beam has high efficiency. In addition, in the Airy beam generator, the sizes of the multiple metasurface unit structures arranged in a two-dimensional array are the same, and only the angle between the connection line of the two openings of the second conductor layer and the connection line of the two openings of the third conductor layer are different, which reduces the manufacturing process of the two-dimensional array and greatly reduces the manufacturing cost.

[0070] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0071] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A metasurface unit structure for electromagnetic wave control, characterized in that: The metasurface unit structure comprises a first conductor layer, a first dielectric layer, a second conductor layer, a second dielectric layer and a third conductor layer arranged in sequence along the incident direction of the electromagnetic wave, wherein the first conductor layer, the second conductor layer and the third conductor layer are perfect electrical conductors corresponding to the electromagnetic wave frequency band; The first conductor layer, the second conductor layer and the third conductor layer each include a complementary double open ring resonator, wherein the complementary double open ring resonator includes two concentric half rings penetrating the conductor layer, the two concentric half rings constitute an open circular ring, and a line connecting two openings of the open circular ring passes through the center of the circle; Wherein, a line connecting the two openings of the first conductor layer and a line connecting the two openings of the third conductor layer are perpendicular to each other; The angle between the connecting line of the two openings of the second conductor layer and the connecting line of the two openings of the third conductor layer and the amplitude of the polarization conversion transmission coefficient of the incident x-polarized electromagnetic wave satisfy the following relationship: A θ =A 45° |sin2θ|, Wherein, θ represents the angle between the connecting line of the two openings of the second conductor layer and the connecting line of the two openings of the third conductor layer, and the value range of θ is [-180°, 180°), A θ A represents the amplitude of the polarization transmission coefficient of the incident electromagnetic wave with x polarization when the angle is θ. 45° It represents the amplitude of the polarization conversion transmission coefficient of the x-polarized incident electromagnetic wave when the angle is 45°.

2. The supersurface unit structure according to claim 1, characterized in that: When the angle θ is in the range of (0°, 90°) or [-180°, -90°], the phase value of the polarization transmission coefficient of the x-polarized incident electromagnetic wave is a first phase value. When the angle θ is in the range of [90°, 180°) or (-90°, 0°], the phase value of the polarization transmission coefficient of the x-polarized incident electromagnetic wave is a second phase value. The phase difference between the first phase value and the second phase value is 180°.

3. An Airy beam generator, characterized in that: A two-dimensional array composed of the metasurface unit structure according to claim 1 or 2 and an electromagnetic wave generating device, wherein; In the first dimension of the two-dimensional array, the size of the angle between the connecting line of the two openings of the second conductor layer of each supersurface unit structure and the connecting line of the two openings of the third conductor layer corresponds to the aperture amplitude of the Airy beam at the position of the supersurface unit structure; the range of values ​​of the angle between the connecting line of the two openings of the second conductor layer of each supersurface unit structure and the connecting line of the two openings of the third conductor layer corresponds to the aperture phase of the Airy beam at the position of the supersurface unit structure.

4. The Airy beam generator according to claim 3, characterized in that: Each metasurface unit structure forms a lattice of a two-dimensional array with a lattice constant of 10 mm.

5. The Airy beam generator according to claim 4, characterized in that: The outer radius of the double open ring resonator is 4.8 mm, the inner radius is 4 mm, the opening width is 0.2 mm, and the thickness of the first conductor layer, the second conductor layer and the third conductor layer are all 0.035 mm.

6. The Airy beam generator according to claim 5, characterized in that: The perfect electrical conductor is a metal.

7. The Airy beam generator according to claim 5 or 6, characterized in that: The first dielectric layer and the second dielectric layer are both made of lossless dielectric materials.

8. The Airy beam generator according to claim 7, characterized in that: The thickness of the first dielectric layer and the second dielectric layer are both 2 mm.

9. The Airy beam generator according to claim 8, characterized in that: The relative bandwidth of the working frequency band of the generator is 25%.

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