Asymmetric double-sided multifunctional total-space metasurface and design method thereof

Abstract

The invention relates to an asymmetric double-sided multifunctional total-space metasurface, and belongs to the technical field of multifunctional electromagnetic regulation and control. The metasurface is formed by non-uniform and periodic arrangement of same or different total space metasurface units, and the arrangement mode, structural parameters and the number of the units are independently controlled. The total space metasurface unit comprises four metal layers and three dielectric layers, and the adjacent metal layers are connected through the dielectric layers; the first metal layer comprises a cross-shaped structure and rectangular strip structures distributed at four corners of the first metal layer, and is used for transmitting x-polarized linearly polarized waves and reflecting y-polarized linearly polarized waves at the same time; the second metal layer comprises a metal patch provided with a cross-shaped groove, provides a transmission window, and reflects the y-polarized linear polarized wave at the same time; each of the third metal layer and the fourth metal layer comprises a cross-shaped structure and is used for transmitting x-polarized linearly polarized waves and reflecting backward incident y-polarized linearly polarized waves, so that asymmetric transmission is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of multifunctional electromagnetic regulation, and relates to an asymmetric double-sided multifunctional full-space metasurface for regulating electromagnetic waves in transmission and reflection modes and a design method thereof. Background Art

[0002] With the development of electromagnetic regulation technology towards multifunctional integration, metasurfaces, as an important branch of artificial electromagnetic structures, their spatial multiplexing ability and asymmetric regulation characteristics have gradually become research hotspots. Traditional metasurfaces are mainly divided into two categories according to their functional attributes: transmissive and reflective types. The former realizes the wavefront manipulation of transmitted waves through phase gradients, while the latter performs phase modulation on reflected waves. However, such single-functional metasurfaces can only work in their designed half-space. When electromagnetic waves are incident from the other side, the device cannot produce effective regulation, resulting in a space utilization rate of less than 50% for the device, which severely restricts the system integration in multi-scenario applications.

[0003] To address the above limitations, researchers have proposed the design concept of double-sided metasurfaces. By constructing a bidirectional channel coding structure, different transmission or reflection functions can be generated respectively during forward and backward incidence. Such structures usually adopt multi-layer metal-dielectric stacked structures and utilize the polarization conversion characteristics to achieve independent regulation of different polarized waves. In a typical design, when linearly polarized waves or circularly polarized waves are incident from both sides of the metasurface, preset transmission / reflection responses can be generated in the forward and backward channels respectively, initially realizing the full-space electromagnetic regulation function. It is worth noting that by introducing asymmetric structure design, the asymmetry of electromagnetic wave transmission can be further realized, which provides a new technical approach for fields such as duplex antenna systems and stealth technologies.

[0004] However, existing double-sided metasurfaces still face many technical bottlenecks: First, most designs can only achieve dual-channel functions in a single frequency band, making it difficult to meet the requirements of modern wireless communication systems for multi-band collaborative operation; Second, when realizing multi-polarization regulation, the electromagnetic coupling effect between different metal layers will cause crosstalk between channels, seriously affecting the independent regulation ability of each channel; Third, traditional periodically arranged units are difficult to meet the full-space multi-beam shaping requirements, and there is a problem of insufficient phase compensation when realizing complex field distributions such as vortex beams and Bessel beams. More critically, existing technologies have not been able to effectively solve the electromagnetic isolation problem between forward incidence and backward incidence, resulting in mutual constraints in the double-sided function design, which directly limits the expansion of the metasurface channel number. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an asymmetric double-sided multifunctional full-space metasurface and a design method thereof, realizing that the metasurface independently realizes transmission and reflection in two frequency bands and reducing the coupling of transmission and reflection between layers of the metasurface.

[0006] To achieve the above object, on the one hand, the present invention provides an asymmetric double-sided multifunctional full-space metasurface, which is composed of the same or different full-space metasurface units arranged non-uniformly and periodically, and the arrangement mode, structural parameters and number of units of the full-space metasurface units are all independently controlled.

[0007] The full-space metasurface unit includes four metal layers and three dielectric layers, and adjacent metal layers are connected through dielectric layers; the first metal layer includes a "cross" structure and rectangular strip structures distributed at the four corners of the first metal layer; the second metal layer includes a metal patch with a "cross" slot; the third metal layer and the fourth metal layer both include a "cross" structure.

[0008] Among them, the first metal layer transmits the x-polarized linear polarized wave and reflects the y-polarized linear polarized wave at the same time; the second metal layer provides a transmission window for the metasurface and reflects the y-polarized linear polarized wave at the same time; the third metal layer and the fourth metal layer both transmit the x-polarized linear polarized wave and reflect the backward-incident y-polarized linear polarized wave to achieve asymmetric transmission.

[0009] Further, in the first metal layer, the arm lengths of the "cross" structure are not equal, and the widths of the four rectangular strip structures are equal while the lengths are not equal. In the second metal layer, the arm lengths of the "cross" slot are equal and the widths are equal. The size of the "cross" structure in the fourth metal layer is the same as that of the "cross" structure in the first metal layer.

[0010] Further, the dielectric layer adopts a dielectric plate with a dielectric constant of 2.65 and a loss tangent of 0.001.

[0011] On the other hand, the present invention provides a design method for an asymmetric double-sided multifunctional full-space metasurface, and the method includes:

[0012] S1. Determine that the four channels of the metasurface are all in the working state of linear polarized waves. Among them, the crosstalk between the four channels is relatively low, and the phase distribution of each channel is arranged according to the phase distribution of the function to be realized.

[0013] S2. Determine the working frequencies, specific linear polarized waves and incident directions of the four channels.

[0014] S3. Determine the transmission phase and amplitude as well as the reflection phase and amplitude of the full-space metasurface unit according to the working frequencies and linear polarization directions of each channel.

[0015] S4. Select appropriate full-space metasurface units for each channel according to the full-space metasurface unit parameters determined in step S3.

[0016] S5. According to the functions of each channel, electromagnetic characteristic simulation is performed on the metasurface to determine the phase distribution of the full-space metasurface units selected for each channel;

[0017] S6. According to the phase distribution determined in step S5, the full-space metasurface units are arranged to obtain the asymmetric double-sided multi-functional full-space metasurface;

[0018] S7. Verify the functions of the four channels of the asymmetric double-sided multi-functional full-space metasurface.

[0019] Further, in step S2, the operating frequencies, specific linear polarized waves, and incident directions of the four channels are as follows: the first channel is an x-polarized linear polarized wave incident in the -z direction at 15 GHz, the second channel is a y-polarized linear polarized wave incident in the -z direction at 15 GHz, the third channel is a y-polarized linear polarized wave incident in the +z direction at 15 GHz, and the fourth channel is a y-polarized linear polarized wave incident in the -z direction at 27 GHz.

[0020] Further, in step S5, the functions of each channel include: the first channel generates a focused beam, the second channel generates a double Bessel beam, the third channel generates a +1-order vortex beam, and the fourth channel generates a +2-order vortex beam.

[0021] Further, in step S7, according to the functions of the first to fourth channels, the functional verification of the obtained asymmetric double-sided multi-functional full-space metasurface includes verifying whether the first channel generates a double-focus focused beam, verifying whether the second channel generates a double Bessel beam, verifying whether the third channel generates a +1-order vortex beam, and verifying whether the fourth channel generates a +2-order vortex beam.

[0022] The beneficial effects of the present invention are as follows:

[0023] (1) The asymmetric double-sided full-space metasurface proposed by the present invention has the characteristics of high electromagnetic regulation freedom and high space utilization rate, and its forward incidence and backward incidence can be isolated, and the functions can be designed independently arbitrarily; in addition, the metasurface realizes high-efficiency integration, and the total number of channels of the metasurface reaches four.

[0024] (2) The proposed asymmetric double-sided full-space metasurface of the present invention can achieve independent beam control in different frequency bands. Specifically, at 15 GHz, it can achieve the transmission of x-polarized linearly polarized waves incident from the -z direction, the reflection of y-polarized linearly polarized waves incident from the -z direction, the reflection of y-polarized linearly polarized waves incident from the +z direction, and at 27 GHz, it can achieve the reflection of y-polarized linearly polarized waves incident from the -z direction, realizing four-channel independent regulation of electromagnetic waves, and solving the coupling between frequency bands and the coupling between metal structures in different layers or the same layer. At the same time, the proposed design method of the asymmetric double-sided multifunctional full-space metasurface of the present invention can be used as a design reference for multifunctional full-space metasurfaces. Through similar methods, more full-space beam control functions can be realized, which has potential application value in the fields of wireless communication, communication transceiver integration, integrated systems, asymmetric transmission, etc.

[0025] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0027] Figure 1 is a functional schematic diagram of the asymmetric double-sided multifunctional full-space metasurface. When an x-polarized wave at 15 GHz is incident from the -z direction, a focused beam can be generated in the transmission half-space. When a y-polarized wave at 15 GHz is incident from the -z direction, a Bessel beam can be generated in the transmission half-space. When a y-polarized wave at 15 GHz is incident from the +z direction, a vortex beam with mode l = +1 can be generated in the transmission half-space. When a y-polarized wave at 27 GHz is incident from the -z direction, a vortex beam with mode l = +2 can be generated in the transmission half-space;

[0028] Figure 2 is a three-dimensional unit structure diagram and a schematic diagram of each metal layer structure of the asymmetric double-sided multifunctional full-space metasurface;

[0029] Figure 3 is a schematic diagram of the transmission and reflection phase and amplitude scan data of the unit of the asymmetric double-sided multifunctional full-space metasurface, Figure 3 (a) is the transmission phase and amplitude of the unit when an x-polarized wave at 15 GHz is incident towards the -z direction, Figure 3 (b) is the reflection phase and amplitude of the unit when a y-polarized wave at 15 GHz is incident towards the -z direction, Figure 3(c) is the reflection phase and amplitude of the unit when the y-polarized wave at 15 GHz is incident in the +z direction, Figure 3 (d) is the reflection phase and amplitude of the unit when the y-polarized wave at 27 GHz is incident in the -z direction;

[0030] Figure 4 are the phase and amplitude data for selecting the unit of the asymmetric double-sided multifunctional full-space metasurface, Figure 4 (a) is the phase of 8 selected units when the x-polarized wave at 15 GHz is incident in the -z direction, Figure 4 (b) is the phase of 4 selected units when the y-polarized wave at 15 GHz is incident in the -z direction, Figure 4 (c) is the phase of 8 selected units when the y-polarized wave at 15 GHz is incident in the +z direction, Figure 4 (d) is the phase of 8 selected units when the y-polarized wave at 27 GHz is incident in the -z direction, Figure 4 (e) is the amplitude of 8 selected units when the x-polarized wave at 15 GHz is incident in the -z direction, Figure 4 (f) is the amplitude of 4 selected units when the y-polarized wave at 15 GHz is incident in the -z direction, Figure 4 (g) is the amplitude of 8 selected units when the y-polarized wave at 15 GHz is incident in the +z direction, Figure 4 (h) is the data of the amplitude of 8 selected units when the y-polarized wave at 27 GHz is incident in the -z direction;

[0031] Figure 5 is the required phase distribution of the asymmetric double-sided multifunctional full-space metasurface, Figure 5 (a) is the phase distribution after the superposition of the focused beam and the horn phase when the x-polarized wave at 15 GHz is incident in the -z direction, Figure 5 (b) is the phase distribution after the superposition of the Bessel beam and the horn phase when the y-polarized wave at 15 GHz is incident in the -z direction, Figure 5 (c) is the phase distribution after the superposition of the vortex beam with mode l = +1 and the horn phase when the y-polarized wave at 15 GHz is incident in the +z direction, Figure 5 (d) is the phase distribution after the superposition of the vortex beam with mode l = +2 and the horn phase when the y-polarized wave at 27 GHz is incident in the -z direction;

[0032] Figure 6 is the normalized electric field intensity of the focused beam when the x-polarized wave at 15 GHz is incident in the -z direction on the asymmetric double-sided multifunctional full-space metasurface, Figure 6 (a) is the electric field on the x-axis and at z = 60 mm on the xoy plane, Figure 6 (b) is the electric field on the xoz plane at y = 0 mm;

[0033] Figure 7 is the normalized electric field strength of the double zero-order Bessel beam when the y-polarized wave of the asymmetric double-sided multifunctional full-space metasurface is incident in the -z direction at 15 GHz. Figure 7 (a) is the double zero-order Bessel beam on the xoz plane. Figure 7 (b) are three observation planes with distances of 200 mm, 230 mm, and 260 mm respectively.

[0034] Figure 8 are the electric field amplitude, phase, and mode purity of the vortex beam of the asymmetric double-sided multifunctional full-space metasurface. Figure 8 (a) is when the y-polarized wave at 15 GHz is incident in the +z direction. Figure 8 (b) is when the y-polarized wave at 27 GHz is incident in the -z direction. Specific implementation mode

[0035] The following illustrates the implementation mode of the present invention through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention schematically. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0036] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and cannot be understood as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged, or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0037] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or position relationship, it is based on the orientation or position relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0038] Embodiment 1

[0039] This embodiment provides an asymmetric double-sided multifunctional full-space metasurface for regulating electromagnetic waves in transmission and reflection modes. The metasurface is formed by arranging full-space metasurface units, as Figure 2 shown. The metasurface unit includes four metal layers and three dielectric layers, and adjacent metal layers are connected by dielectric layers. Among them, the metal layer is made of copper, with a thickness of t = 0.035 mm. The dielectric layer is a dielectric plate with a dielectric constant of 2.65 and a loss tangent of 0.001. The thickness of the dielectric plate is h = 1.5 mm, and the width is p = 8 mm.

[0040] The metasurface unit includes the first to fourth metal layers, and adjacent metal layers are connected by dielectric layers.

[0041] Among them, the first metal layer includes a "cross" structure and four rectangular strip structures; the "cross" structure is located in the middle area of the first metal layer, and the two arms of the "cross" are of unequal length. The widths of the four rectangular strips are equal, but the lengths are unequal, and the four rectangular strips are respectively located at the four corners of the first metal layer. This first metal layer transmits the x-polarized linearly polarized wave and reflects the y-polarized linearly polarized wave at the same time.

[0042] The second metal layer is a metal sheet with a "cross" slot; among them, the two arms of the "cross" are of equal length. This second metal layer provides a transmission window for the metasurface and reflects the y-polarized linearly polarized wave at the same time.

[0043] The third and fourth metal layers are both a "cross" structure, and the two arms of the "cross" are of unequal length. Among them, both the third metal layer and the fourth metal layer transmit the x-polarized linearly polarized wave and are used for the reflection of the y-polarized linearly polarized wave when it is incident from the back of the metasurface, realizing asymmetric transmission.

[0044] The metasurface proposed in this embodiment can independently regulate the transmitted wave and the reflected wave in two frequency bands, as Figure 1 shown. At 15 GHz, it can achieve the transmission of the x-polarized linearly polarized wave when incident from the -z direction, the reflection of the y-polarized linearly polarized wave when incident from the -z direction, and the reflection of the y-polarized linearly polarized wave when incident from the +z direction; at 27 GHz, it can achieve the reflection of the y-polarized linearly polarized wave when incident from the -z direction.

[0045] In this embodiment, the specific structural parameters of the metasurface unit include:

[0046] In the first metal layer, the lengths dx and dy of the "cross"-shaped patches in the x and y directions, the widths la and lb of the "cross"-shaped patches in the x and y directions, and the lengths w and fy of the four rectangular metal strips in the x and y directions; in addition, the periods of the first metal layer in the x and y directions are both p. The values of some parameters are as follows: la = 0.8 mm, lb = 0.8 mm, w = 0.5 mm.

[0047] In the second metal layer, the lengths of the "cross"-shaped slots in the x and y directions are both ld, and the widths are both lc, where ld = 5 mm and the widths are both lc = 1.2 mm.

[0048] In the third metal layer, the length of the "cross"-shaped patch in the y direction is p, and the other parameters are the same as those of the cross-shaped patch in the first metal layer. Among them, p = 8 mm.

[0049] In the fourth metal layer, the length of the "cross"-shaped patch in the y direction is ey, and the other parameters are the same as those of the cross-shaped patch in the first metal layer.

[0050] Embodiment 2

[0051] This embodiment provides a design method for an asymmetric double-sided full-space metasurface, including the following steps:

[0052] Step 1: Determine the polarization working states of the four channels, all of which are linearly polarized waves.

[0053] Step 2: Determine the operating frequencies, specific linearly polarized waves, and incident directions of the four channels. Among them, Channel 1 is an x-polarized wave incident in the -z direction at 15 GHz, Channel 2 is a y-polarized wave incident in the -z direction at 15 GHz, Channel 3 is a y-polarized wave incident in the +z direction at 15 GHz, and Channel 4 is a y-polarized wave incident in the -z direction at 27 GHz.

[0054] Step 3: According to the transmission phase and amplitude, and reflection phase and amplitude of the predetermined linearly polarized channel analysis unit, the transmission amplitude and reflection amplitude of the unit should both reach above -3 dB, and the transmission phase and reflection phase should have a good coverage rate.

[0055] Step 4: Select appropriate units according to the results analyzed in Step 3, that is, the transmission amplitude and reflection amplitude of the unit should reach above -3 dB, and the phase should have a good coverage rate according to the number of selected units.

[0056] In this embodiment, 8 units are selected for Channel 1, 4 units are selected for Channel 2, 8 units are selected for Channel 3, and 8 units are selected for Channel 4.

[0057] Step 5: Determine the phase distribution of the required units according to the functions of the predetermined linearly polarized channels.

[0058] In this embodiment, Channel 1 generates a focused beam, Channel 2 generates a double Bessel beam, Channel 3 generates a +1-order vortex beam, and Channel 4 generates a +2-order vortex beam.

[0059] Step 6: Arrange the metasurface array according to the phase distribution in Step 5.

[0060] Step 7: Verify the functions of the four channels of the metasurface.

[0061] Among them, for Channel 1, verify whether a focused beam with double foci is generated; for Channel 2, verify whether a double Bessel beam is generated; for Channel 3, verify whether a +1-order vortex beam is generated; for Channel 4, verify whether a +2-order vortex beam is generated.

[0062] Simulate the electromagnetic characteristics of the metasurface in the numerical simulation software CST Microwave Studio.

[0063] Figure 3 and Figure 4 respectively give the two-dimensional collinear polarization transmission and reflection amplitudes and phase scanning electromagnetic characteristics of the metasurface unit under the excitation of x- and y-polarized waves at two frequencies of 15 GHz and 27 GHz. When performing CST parameter scanning, other structural parameters of the metasurface unit remain unchanged (specific values are as described in Embodiment 1), only changing the lengths dx, dy, ey, and fy of the cross patches in the x and y directions. Among them, the variation range of dx is 2.00 - 6.09 mm, the simulation frequency band is 14 - 16 GHz, the variation range of dy is 3.00 - 8.00 mm, the simulation frequency band is 14 - 16 GHz, the variation range of ey is 3.00 - 8.00 mm, the simulation frequency band is 14 - 16 GHz, and the variation range of fy is 1.00 - 2.00 mm, the simulation frequency band is 26 - 28 GHz. From Figure 3 it can be seen that the metasurface unit provided in this embodiment has good phase coverage, and the amplitudes all reach above -3 dB; from Figure 4 it can be seen that the selected units all have good phase coverage, and the amplitudes all reach above -3 dB.

[0064] Figure 5 Shown is the phase distribution required by the asymmetric double-sided full-space metasurface provided in this embodiment under different polarized waves and different incident directions. It can be seen that to enable the asymmetric double-sided full-space metasurface to achieve the corresponding functions, the metasurface array should be arranged according to the Figure 5 (a) - Figure 5 (d) shown final phase distribution.

[0065] Figure 6The normalized electric field intensity of the focused beam of the asymmetric double-sided multifunctional full-space metasurface under the incidence of the x-polarized wave at 15 GHz in the -z direction is shown. The results show that the metasurface generates a double-focus focused beam with good focusing and equal energy distribution at the two foci.

[0066] Figure 7 The normalized electric field intensity of the double zero-order Bessel beam of the asymmetric double-sided multifunctional full-space metasurface under the incidence of the y-polarized wave at 15 GHz in the -z direction is shown. The results show that the metasurface generates a double zero-order Bessel beam, and the normalized electric field intensity of the beam decreases with the increase of the propagation distance of the electromagnetic wave. Moreover, the normalized electric field intensity distributions of the two beams at the same distance are symmetric. This phenomenon indicates that the energies of the two beams are basically the same.

[0067] Figure 8 The electric field amplitude, phase, and mode purity of the vortex beam of the asymmetric double-sided multifunctional full-space metasurface are shown. It can be seen that a vortex beam with mode l = +1 is generated at 15 GHz with a mode purity of 74.33%, while the mode purity of all other modes is lower than 7%. A vortex beam with mode l = +2 is generated at 27 GHz with a mode purity of 73.44%, while the mode purity of all other modes is lower than 8%, meeting the design requirements.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An asymmetric double-sided multi-functional full-space metasurface, which is formed by non-uniform and periodic arrangement of the same or different full-space metasurface units, and the arrangement mode, structural parameters and number of units of the full-space metasurface units are all independently controlled, and is characterized in that: The full-space metasurface unit includes four metal layers and three dielectric layers, and adjacent metal layers are connected by dielectric layers; the first metal layer includes a "cross" structure and rectangular strip structures distributed at the four corners of the first metal layer; the second metal layer includes a metal patch with a "cross" slot; the third metal layer and the fourth metal layer both include a "cross" structure; Among them, the first metal layer transmits the x-polarized linear polarized wave and reflects the y-polarized linear polarized wave at the same time; the second metal layer provides a transmission window for the metasurface and reflects the y-polarized linear polarized wave at the same time; the third metal layer and the fourth metal layer both transmit the x-polarized linear polarized wave and reflect the backward-incident y-polarized linear polarized wave.

2. The asymmetric double-sided multi-functional full-space metasurface according to claim 1, wherein: In the first metal layer, the lengths of the two arms of the "cross" structure are not equal, and the widths of the four rectangular strip structures are equal, but the lengths are not equal.

3. The asymmetric double-sided multifunctional full-space metasurface according to claim 1, wherein: In the second metal layer, the lengths of the two arms of the "cross" slot are equal and the widths are equal.

4. The asymmetric double-sided multifunctional full-space metasurface according to claim 1, characterized in that: The size of the "cross" structure in the fourth metal layer is the same as that of the "cross" structure in the first metal layer.

5. The asymmetric double-sided multi-functional full-space metasurface according to claim 1, characterized in that: The dielectric layer uses a dielectric plate with a dielectric constant of 2.65 and a loss tangent of 0.

001.

6. A design method for an asymmetric double-sided multi-functional full-space metasurface, characterized in that, The method includes: S1. Determine that the four channels of the metasurface are all in the working state of linear polarized waves; S2. Determine the working frequencies, specific linear polarized waves, and incident directions of the four channels; S3. Determine the transmission phase and amplitude, and reflection phase and amplitude of the full-space metasurface unit according to the working frequencies and linear polarization directions of each channel; S4. Select appropriate full-space metasurface units for each channel according to the parameters of the full-space metasurface unit determined in step S3; S5. According to the functions of each channel, determine the phase distribution of the selected full-space metasurface units for each channel by electromagnetic characteristic simulation of the metasurface; S6. Arrange the full-space metasurface units according to the phase distribution determined in step S5 to obtain the asymmetric double-sided multifunctional full-space metasurface; S7. Verify the functions of the four channels of the asymmetric double-sided multifunctional full-space metasurface.

7. The method according to claim 6, wherein In step S2, the working frequencies, specific linear polarized waves, and incident directions of the four channels are respectively: the first channel is the x-polarized linear polarized wave incident in the -z direction at 15 GHz, the second channel is the y-polarized linear polarized wave incident in the -z direction at 15 GHz, the third channel is the y-polarized linear polarized wave incident in the +z direction at 15 GHz, and the fourth channel is the y-polarized linear polarized wave incident in the -z direction at 27 GHz.

8. The method according to claim 6, wherein In step S5, the functions of each channel include: the first channel generates a focused beam, the second channel generates a double Bessel beam, the third channel generates a +1 order vortex beam, and the fourth channel generates a +2 order vortex beam.

9. The method according to claim 8, wherein According to the functions of the first channel to the fourth channel, the function verification of the obtained asymmetric double-sided multifunctional full-space metasurface includes verifying whether the first channel generates a double-focus focused beam, verifying whether the second channel generates a double Bessel beam, verifying whether the third channel generates a +1 order vortex beam, and verifying whether the fourth channel generates a +2 order vortex beam.

Images