Circular polarization multiplexing metasurface for integrated regulation and control of radiation waves and reflected waves, antenna and communication equipment

Abstract

The invention discloses a circular polarization multiplexing metasurface capable of integrally regulating and controlling radiation waves and reflection waves, an antenna and communication equipment. The metasurface is formed by periodically arranging metasurface units in the x direction and the y direction. The metasurface unit sequentially comprises a patch layer, a first dielectric substrate, an isolation ground, a bonding layer, a second dielectric substrate and a phase delay layer from top to bottom; the patch layer comprises a left-hand circularly-polarized patch resonator and a holed quadrilateral annular structure on the periphery of the left-hand circularly-polarized patch resonator, a second metal through hole penetrating through each layer is formed in the center of the metasurface unit, and the patch resonator is connected with the phase delay layer through the second metal through hole; the geometric phase of the metasurface unit is controlled by the rotation angle of the patch resonator, the transmission phase is controlled by the delay line length of the phase delay layer, and decoupling of the radiation phase and the reflection phase can be achieved. According to the invention, the radiation wave and the reflection wave can be simultaneously and independently regulated and controlled, and the capability of regulating and controlling various types of electromagnetic waves by the metasurface is expanded.

Description

Technical Field

[0001] The present invention belongs to the field of metamaterials, and in particular relates to a circularly polarized multiplexing metasurface, an antenna, and a communication device for integrating and controlling radiation waves and reflected waves. Background Art

[0002] As a two-dimensional metamaterial, metasurfaces can flexibly control a variety of fundamental properties of electromagnetic waves, such as amplitude, phase, polarization, and propagation direction. They also offer advantages such as low profile, ease of integration, and low cost. Currently, many studies have used metasurfaces to manipulate single forms of electromagnetic waves (such as reflected, transmitted, or radiated waves) to achieve various functions. However, in the face of increasingly complex electromagnetic environments, simply modulating the reflection, transmission, or radiation properties of electromagnetic waves is no longer enough to meet the growing demand.

[0003] In recent years, the integrated control of both radiated and reflected waves has become a hot research topic in fields such as antennas and radar detection. A series of studies have combined metasurfaces and antenna structures on the same plane or stacked one on top of the other, with the metasurface primarily responsible for controlling the reflected wave, while the antenna controls the radiated wave. When the metasurface's geometry changes, the reflection phase response also changes, while the antenna's radiation performance remains relatively unaffected. This allows for the realization of different radiation and reflection functions with low crosstalk. However, these studies require separate design of the metasurface and antenna structures, often resulting in higher profiles and requiring additional consideration of coupling between the structures. On the other hand, some studies have utilized a single metasurface to simultaneously control both radiated and reflected waves. However, these studies have currently only been able to achieve simple reflection functions, such as radar cross-section (RCS) reduction and beam steering, and simple radiation functions, such as wide-beam and dual-beam radiation. They lack the ability to directly, flexibly, and independently implement complex radiation and reflection functions. Summary of the Invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a circularly polarized multiplexing metasurface that integrates the control of radiation waves and reflected waves, so as to improve the problems of complex design and high profile, and realize the simultaneous and independent control of radiation waves and orthogonal circularly polarized reflected waves.

[0005] Technical solution: The metasurface described in the present invention is composed of metasurface units periodically arranged along the x and y directions. The metasurface unit includes a patch layer, a first dielectric substrate, an isolation ground, an adhesive layer, a second dielectric substrate and a phase delay layer from top to bottom. The patch layer includes a left-handed circularly polarized patch resonator and a four-sided ring structure with holes around it. A second metal through-hole is provided at the center of the metasurface unit, which passes through all layers. The patch resonator and the phase delay layer are connected through the second metal through-hole, so that electromagnetic energy is transmitted from the phase delay layer to the patch resonator. The geometric phase of the reflected wave and the radiated wave is controlled by the rotation angle of the patch resonator, and the transmission phase of the radiated wave is controlled by the delay line length of the phase delay layer. When the patch resonator is excited by the guided wave, the metasurface unit will radiate a left-handed circularly polarized wave. When the right-handed circularly polarized wave irradiates the metasurface unit, the electromagnetic energy cannot be received and is still reflected back to the free space in the form of a right-handed circularly polarized wave.

[0006] Optionally, the through holes on the perforated quadrilateral ring structure are arranged in a ring shape, the first dielectric substrate is provided with first metal through holes matching the through holes on the perforated quadrilateral ring structure, and the isolation ground is provided with through holes matching the first metal through holes.

[0007] Optionally, the patch resonator is an irregular octagonal metal patch structure etched with a rectangular through hole, and the center of the rectangular through hole deviates from the center of the metasurface unit.

[0008] Optionally, the irregular octagonal metal patch structure is based on a square structure with a side length of a, and two groups of diagonals are cut according to the set size, and one group of diagonals is cut off with a right angle side of t a The isosceles right triangle, the other set of diagonals cut off the right angle side is t b An isosceles right triangle.

[0009] Optionally, the phase delay layer is a phase delay line, one end of the phase delay line is located at the center of the metasurface unit, and different lengths of the phase delay line correspond to different transmission phases.

[0010] Optionally, an isolation ground is used to isolate the mutual coupling between the patch resonator and the phase delay layer.

[0011] Optionally, the rotation angle of the patch resonator of each metasurface unit in the metasurface is independently controlled.

[0012] Optionally, when the metasurface unit is illuminated by a right-handed circularly polarized wave, the reflected wave Expressed as:

[0013]

[0014] Among them, J lin (α) is the linear basis vector Jones matrix of the patch resonator rotated α degrees, α is the rotation angle of the patch resonator, is the incident electric field, E0 is the electric field amplitude, For a right-hand circularly polarized wave propagating in the +z direction, the phase of the reflected wave will lead by 2α;

[0015] When the patch resonator is excited by a guided wave transmitted through a phase delay line, a left-handed circularly polarized wave will be radiated directly from the metasurface unit into the free space, expressed as:

[0016]

[0017] in, is the electric field of the radiation wave, is a left-hand circularly polarized wave propagating in the +z direction, and β is the transmission phase introduced by the phase delay line. After the same rotation operation, the radiated wave is rewritten as:

[0018]

[0019] in, is the electric field of the radiated wave after rotating the patch resonator by α degrees, and M(-α) is the rotation matrix of rotating the patch resonator by -α degrees; then the phase of the left-hand circularly polarized radiated wave will advance by -α+β, and the phase responses of the reflected wave and the radiated wave will be decoupled.

[0020] The antenna described in the present invention includes the circularly polarized multiplexing metasurface that integrates and controls radiation waves and reflected waves.

[0021] The communication device described in the present invention includes the circularly polarized multiplexing metasurface that integrates and controls the radiated waves and the reflected waves.

[0022] Beneficial effects: Compared with the prior art, the significant technical effects of the present invention are: (1) the metasurface unit can be used as an antenna array element to control the radiation wave, and can also be used as a reflective metasurface unit to control the reflection wave; when the patch resonator is excited by the waveguide, the unit will radiate a left-handed circularly polarized wave; however, when the right-handed circularly polarized wave is irradiated on the unit, due to the polarization mismatch, the electromagnetic energy cannot be received and is reflected back to the free space in the form of a right-handed circularly polarized wave; by combining the geometric phase obtained by rotating the patch resonator and the transmission phase obtained by changing the length of the phase delay line, decoupled radiation and reflection phases can be obtained, thereby realizing independent control of the radiation wave and the reflection wave; (2) there is a circle of metal through-holes between the patch layer and the isolation ground, which can prevent the propagation of surface waves, thereby effectively suppressing mutual coupling between units; (3) the metasurface unit has different phase responses to the radiation wave and the orthogonal circularly polarized reflection wave, so the radiation wave and the reflection wave can be controlled at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1Schematic diagram of the structure of the metasurface unit of the present invention, wherein (a) is a schematic diagram of the unit layered structure, (b) is a schematic diagram of the patch layer, and (c) is a schematic diagram of the phase delay line layer;

[0024] Figure 2 Schematic diagram of the simulation results of the metasurface unit, where (a) is a schematic diagram of the reflection amplitude changing with the rotation angle, (b) is a schematic diagram of the reflection phase changing with the rotation angle, and (c) is a schematic diagram of the radiation amplitude and S 11 Schematic diagram of the change with the rotation angle, (d) is a schematic diagram of the change of radiation phase with the rotation angle;

[0025] Figure 3 Schematic diagram of dual-beam gain arbitrary allocation and RCS reduction phase distribution and simulation, where (a) is the calculated RCS reduction reflection phase distribution, (b) is the rotation angle distribution, (c) is the simulated RCS far-field pattern, (d) is the radiation phase distribution of Example I, (e) is the transmission phase distribution of Example I, (f) is the far-field pattern of Example I, (g) is the radiation phase distribution of Example II, (h) is the transmission phase distribution of Example II, (i) is the far-field pattern of Example II, (j) is the radiation phase distribution of Example III, (k) is the transmission phase distribution of Example III, and (l) is the far-field pattern of Example III;

[0026] Figure 4 Schematic diagram of dual-channel holographic imaging phase distribution and simulation, where (a) is the reflection phase distribution of Example IV, (b) is the rotation angle distribution of Example IV, (c) is the near-field simulation result of Example IV, (d) is the radiation phase distribution of Example IV, (e) is the transmission phase distribution of Example IV, (f) is the near-field simulation result of Example IV, (g) is the reflection phase distribution of Example V, (h) is the rotation angle distribution of Example V, (i) is the near-field simulation result of Example V, (j) is the radiation phase distribution of Example V, (k) is the transmission phase distribution of Example V, and (l) is the near-field simulation result of Example V;

[0027] Figure 5 Schematic diagrams of the far-field test environment and the sample processed in Example I, where (a) is the far-field test environment in radiation mode, (b) is the far-field test environment in reflection mode, (c) is a schematic diagram of the front side of Example I, and (d) is a schematic diagram of the back side of Example I;

[0028] Figure 6 The far-field functional test results of Example I are shown in Figure 1, where (a) is the S of the simulation and test. 11 , (b) is the far-field radiation pattern of 10.3GHz simulation and test, (c) is the schematic diagram of the change of dual-beam gain and axial ratio with frequency in simulation and test, (d) is the schematic diagram of the change of co-polarization and cross-polarization RCS reduction with frequency in simulation and test;

[0029] Figure 7 Schematic diagrams of the near-field test environment and the sample processed in Example V, where (a) is the near-field test environment in radiation mode, (b) is the near-field test environment in reflection mode, (c) is a schematic diagram of the front side of Example V, and (d) is a schematic diagram of the back side of Example V;

[0030] Figure 8 Schematic diagram of the near-field functional test results of example V, where (a) is the simulated and tested S 11 , (b) is the radiation near-field scanning result of the letter “y”, and (c) is the reflection near-field scanning result of the letter “L”. DETAILED DESCRIPTION

[0031] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0032] The circular polarization multiplexing metasurface for integrated control of radiation wave and reflection wave of the present invention is composed of metasurface units arranged periodically along the x and y directions. Figure 1 As shown in (a), the metasurface unit includes, from top to bottom, a patch layer 1, a first dielectric substrate 2, an isolation ground 3, an adhesive layer 4, a second dielectric substrate 5, and a phase delay line 6.

[0033] like Figure 1 As shown in (a) and (b), the patch layer 1 includes a left-handed circularly polarized patch resonator and a peripheral hole-shaped quadrilateral ring structure. The through holes on the hole-shaped quadrilateral ring structure are arranged in a ring. The patch resonator is an irregular octagonal metal patch structure etched with rectangular through holes. It is based on a square structure with a side length of a. Two groups of diagonals are cut to a set size. One group of diagonals is cut to remove the right angle side t a The isosceles right triangle, the other set of diagonals cut off the right angle side is t b The length and width of the etched rectangular through hole are l a , l b The distance between the center of the rectangular through hole and the center of the metasurface unit is v x By optimizing the length of the cut corners and the size of the rectangular through-holes, the polarization purity of the left-handed circularly polarized (LCP) radiation wave is improved. At the same time, the rotation angle of the patch resonator on the top layer of each metasurface unit in the metasurface is set according to the phase distribution of the designed reflection function. That is, the angle of each patch resonator depends on the function of the designed reflection wave. Different functions correspond to different metasurface phase distributions, and further correspond to the rotation angle distribution. For example: if you want to achieve Figure 3 The RCS reduction function shown in (c) requires a reflection phase distribution such as Figure 3As shown in (a) in Figure 1. According to formula (8), the reflection phase is equal to twice the rotation angle, so the rotation angle distribution can be calculated as Figure 3 As shown in (b).

[0034] like Figure 1 As shown in (a), the first dielectric substrate 2 is provided with first metal through holes 7 that match the through holes on the patch layer 1 and are arranged in a circular shape, in order to reduce unnecessary coupling effects between adjacent units of the metasurface.

[0035] The isolation ground is used to isolate the mutual coupling between the patch resonator and the phase delay line, and is provided with through holes matching the through holes on the patch layer 1 and the first metal through holes 7 of the first dielectric substrate 2 .

[0036] like Figure 1 As shown in (c), the phase delay line 6 is a meandering line with a width of w. By designing phase delay lines of different lengths, different transmission phases β are introduced. One end of the phase delay line 6 is located at the center of the metasurface unit.

[0037] like Figure 1 As shown in (a), a second metal through-hole 8 is provided at the center of the metasurface unit. The second metal through-hole 8 passes through the patch layer 1, the first dielectric substrate 2, the isolation ground 3, the adhesive layer 4 and the second dielectric substrate 5, connecting the upper patch resonator and the lower phase delay line 6 to ensure that the electromagnetic energy can be transmitted from the phase delay line to the patch resonator.

[0038] The feeding point of the patch resonator is located at the center of the unit structure and is connected to the phase delay line through a second metal through-hole. The geometric phase of the metasurface unit is controlled by the rotation angle of the patch resonator, and the transmission phase of the metasurface unit is controlled by the length of the phase delay line. When the patch resonator is excited by the waveguide, the metasurface unit will radiate a left-handed circularly polarized wave. However, when a right-handed circularly polarized wave irradiates the metasurface unit, the electromagnetic energy cannot be received and is still reflected back to the free space in the form of a right-handed circularly polarized wave. By combining the geometric phase introduced by rotating the patch resonator and the transmission phase obtained by changing the length of the phase delay line, the decoupling of the radiation phase and the reflection phase can be achieved. The present invention can achieve simultaneous and independent control of the radiation wave and the reflected wave, expanding the ability of the metasurface to control various types of electromagnetic waves.

[0039] In this embodiment, the aperture d of the second metal through hole 8 is 0.65 mm; the period of the metasurface unit is 12 mm; the dielectric constant of the medium used in the first dielectric substrate is 4.4, the loss tangent is 0.0025, and the thickness h1 is 2.5 mm; the dielectric constant of the medium used in the adhesive layer is 3.7, the loss tangent is 0.004, and the thickness is 0.101 mm; the dielectric constant of the medium used in the second dielectric substrate is 3.5, the loss tangent is 0.002, and the thickness h2 is 0.508 mm. Figure 1 (b) and (c) are schematic diagrams of the structure of the patch resonator and phase delay line respectively. The specific geometric parameters are as follows: a =1.6mm, t b =0.8mm, l a =1.5mm, l b =5mm, v x =1.275mm, d=0.65mm, w=0.65mm, k=3mm. When the patch resonator is excited by the waveguide, the metasurface unit will radiate a left-handed circularly polarized wave. However, when the right-handed circularly polarized wave is irradiated on the metasurface unit, due to the polarization mismatch, the electromagnetic energy cannot be received, and is reflected back to the free space in the form of a right-handed circularly polarized (RCP) wave. Based on this unique property, by rotating the patch resonator α degrees alone, the right-handed circularly polarized reflected wave will be added with a geometric phase. In addition, the phase delay line will also bring a transmission phase to the radiated wave, so that the geometric phase and the transmission phase can work together to produce decoupled radiation phase and reflection phase. It should be pointed out that the shape of the phase delay line is not necessarily a bent straight line, and can be designed as any shape such as a curve, as long as the same length is achieved.

[0040] In order to further understand the independent control mechanism of radiation wave and reflection wave, Jones matrix is used to explain it. Consider a passive, lossless and reciprocal metasurface unit, whose reflection characteristics can be expressed by an ideal circular basis Jones matrix J cir express:

[0041]

[0042] Wherein, the subscripts L and R represent left-hand circular polarization and right-hand circular polarization, respectively; LR is the reflection coefficient of the incident right-hand circularly polarized wave and the reflected left-hand circularly polarized wave; r LL is the reflection coefficient of the incident left-hand circularly polarized wave and the reflected left-hand circularly polarized wave; r RR is the reflection coefficient of the incident right-hand circularly polarized wave and the reflected right-hand circularly polarized wave; r RL is the reflection coefficient of the incident left circularly polarized wave and the reflected right circularly polarized wave. Then, the Jones matrix of the linear basis vector J lin The calculation formula is:

[0043]

[0044] Wherein, the subscripts x and y represent x-polarization and y-polarization respectively; xx is the reflection coefficient of the incident x-polarized wave and the reflected x-polarized wave; r xy is the reflection coefficient of the incident y-polarized wave and the reflected x-polarized wave; ryx is the reflection coefficient of the incident x-polarized wave and the reflected y-polarized wave; r yy is the reflection coefficient of the incident y-polarized wave and the reflected y-polarized wave; is the coordinate transformation factor, Λ -1 is the inverse matrix of Λ.

[0045] Assuming that the patch resonator is rotated by an arbitrary angle α relative to the z-axis, the Jones matrix can be further rewritten as:

[0046] J lin (α)=M(-α)J lin M(α)=e j2α J lin (3)

[0047] in, is the rotation matrix of the patch resonator α degrees, M(-α) is the rotation matrix of the patch resonator -α degrees, and J lin (α) is the linear basis vector Jones matrix of the rotated patch resonator α degrees. When the metasurface unit is irradiated by a right-handed circularly polarized wave along the -z direction, the incident electric field It can be expressed as:

[0048]

[0049] Where E0 is the electric field amplitude, is a right-hand circularly polarized wave propagating along the -z direction. Then, the reflected wave It can be expressed as:

[0050]

[0051] in, It is a right-hand circularly polarized wave propagating in the +z direction. The phase of the reflected wave will lead by 2α.

[0052] When the patch resonator is excited by a guided wave transmitted through a phase delay line, a left-handed circularly polarized wave will be radiated directly from the metasurface unit into the free space, which can be expressed as:

[0053]

[0054] in, is the electric field expression of the radiation wave, is a left-hand circularly polarized wave propagating in the +z direction, and β is the transmission phase introduced by the phase delay line. After the same rotation operation, the radiated wave can be rewritten as:

[0055]

[0056] in, The electric field expression for the radiated wave when the patch resonator is rotated by α degrees is shown in Figure 1. This indicates that the phase of the left-handed circularly polarized radiated wave advances by -α+β. Therefore, the phase responses of the reflected and radiated waves are decoupled.

[0057] Assume a metasurface composed of M×N metasurface units, whose reflection phase and radiation phase Can be expressed as:

[0058]

[0059] Among them, α ij Here, i = 1, 2, ..., M, j = 1, 2, ..., N, M is the number of units contained in the metasurface in the x direction, and N is the number of units contained in the metasurface in the y direction.

[0060] It can be seen from formulas (8) and (9) that the metasurface has decoupled radiation and reflection phase distributions, which can realize arbitrary radiation and reflection functions in the orthogonal circular polarization state.

[0061] like Figure 2 (a) to (d) are schematic diagrams of the simulation results of the metasurface unit. Figure 2 (a) shows the relationship between the reflection amplitude of the metasurface unit under the illumination of right-handed circularly polarized waves and the rotation angle α of the patch resonator. It can be seen that from 10.1 to 10.65 GHz, the co-polarization (co-pol) reflection amplitude r RR is always not less than -1dB, and the cross-polarization (cro-pol) reflection amplitude r LR It is suppressed below -10dB. This shows that most of the reflected waves maintain their original polarization. Figure 2 (b) shows the relationship between the co-polarization reflection phase response and the rotation angle α. The reflection phase increases linearly and is equal to twice the rotation angle. The amplitude of the radiated wave and the reflection coefficient S 11 like Figure 2 As shown in (c). The reflection coefficient is the ratio of reflected energy to incident energy, expressed in logarithmic form. The lower the value, the less energy is reflected. It can be seen that in the range of 10 to 10.6 GHz, the amplitude of the left-hand circularly polarized wave is always greater than -1.4 dB, while the amplitude of the right-hand circularly polarized wave is less than -12 dB. In addition, the reflection coefficient S in this frequency band is 11 It is always lower than -15dB, which shows that the left-hand circularly polarized wave has good impedance matching and high polarization purity. Figure 2 As shown in (d), the phase of the left-hand circularly polarized radiation decreases linearly as the patch resonator rotates counterclockwise and is equal to one rotation angle.

[0062] like Figure 3(a) to (l) show the phase distribution and simulation diagrams of arbitrary dual-beam gain allocation and radar cross section (RCS) reduction. In this embodiment, a metasurface composed of 16×16 metasurface units is designed. For the reflection function, the far field of the reflected wave of the metasurface composed of M×N metasurface units is It can be expressed as:

[0063]

[0064] Where k = 2π / λ represents the wavelength, P represents the period of the metasurface unit, The response of the feed, is the response of the mnth metasurface unit, θ is the pitch angle of the observation point relative to the center of the metasurface, is the azimuth angle of the observation point relative to the center of the metasurface, θ mn is the pitch angle of the observation point relative to the center of the mnth metasurface unit, is the azimuth angle of the observation point relative to the center of the mnth metasurface unit. For the radiation function, since each metasurface unit is excited with equal amplitude and phase, the radiation wave far field Can be simplified to:

[0065]

[0066] The present invention uses the particle swarm optimization algorithm to calculate the optimal phase distribution. For dual-beam radiation with arbitrary gain distribution, the fitness function F1 can be expressed as:

[0067]

[0068] in, and Represents the pth main beam pointing direction The simulation gain and target gain, SL and SL t represent the simulated and target sidelobe levels respectively, w1 is the weight coefficient for optimizing the gain difference, w2 is the weight coefficient for optimizing the sidelobe level, θ p is the elevation angle of the pth main beam, is the azimuth angle of the pth main beam. In order to reduce the RCS, the incident wave should be reflected in all directions by the metasurface, so the fitness function F2 can be expressed as:

[0069]

[0070] The present invention designs three examples, which can realize dual-beam radiation with different gain distributions, and all have low RCS characteristics. Figure 3 (a) is the RCS reduction phase distribution obtained by numerical calculation, and the rotation angle distribution can be further calculated, such as Figure 3 As shown in (b). Figure 3 (c) shows the simulated far-field pattern of the reflected wave of Example I when the metasurface is illuminated by a right-handed circularly polarized plane wave. The incident plane wave is reflected by the metasurface in all directions in the free space, thereby achieving a low RCS. In terms of radiation function, two left-handed circularly polarized radiation beams B1 and B2 are designed to point to -30° and 20° respectively. For Examples I, II and III, the gain difference between the two beams is designed to be 5dB, 0dB and -3dB respectively. The radiation phase distribution after optimization of Example I is shown in Figure 1. Figure 3 As shown in (d), the transmission phase distribution is obtained based on the calculated rotation angle distribution, as shown in Figure 3 The corresponding far-field radiation pattern is shown in (e). Figure 3 As shown in (f), two main beams pointing to -30.8° and 19.8° can be observed, with a gain difference of 4.9dB. The radiation phase distribution after optimization in Example II is as follows: Figure 3 As shown in (g), the transmission phase distribution is as follows Figure 3 As shown in (h). The simulated far-field radiation pattern is as follows Figure 3 As shown in (i), two main beams pointing to -29.8° and 18.4° can be observed, with a gain difference of -0.5dB. The radiation phase distribution and transmission phase distribution after optimization in Example III are shown as follows: Figure 3 (j) and Figure 3 The simulated far-field radiation pattern is shown in (k). Figure 3 As shown in (l), two main beams pointing at -30.2° and 21.1° are observed, with a gain difference of -3dB. All simulation results were obtained at 10.3GHz and are in good agreement with the preset targets.

[0071] like Figure 4 (a) to (l) show the phase distribution and simulation diagram of dual-channel holographic imaging. The present invention designs two embodiments. Example IV can realize the near-field holographic imaging of three points in the dice in the radiation channel, and realize the near-field holographic imaging of four points in the dice in the reflection channel; Example V can realize the near-field holographic imaging of the letter "y" in the radiation channel, and realize the near-field holographic imaging of the letter "L" in the reflection channel. The holographic imaging algorithm adopts the classic Gerchberg-Saxton algorithm. In Example IV, as Figure 4 (a) shows the phase distribution corresponding to the four-point image obtained by numerical calculation. Figure 4 (b) is the corresponding rotation angle distribution, Figure 4 (c) in the middle is the calculated holographic imaging image, where clear four-point images can be seen. Figure 4 (d) is the radiation phase distribution corresponding to the three-point image obtained by numerical calculation. Figure 4 (e) is the corresponding transmission phase distribution, Figure 4 (f) is the calculated holographic image, and a clear three-point image can be seen. Figure 4 (g) shows the phase distribution corresponding to the letter "L" obtained by numerical calculation. Figure 4 (h) is the corresponding rotation angle distribution, Figure 4 (i) in the middle is the calculated holographic imaging image, in which a clear image of the letter "L" can be seen. Figure 4 (j) is the radiation phase distribution corresponding to the letter "y" obtained by numerical calculation. Figure 4 Where (k) is the corresponding transmission phase distribution, Figure 4 The middle (l) is the calculated holographic imaging image, in which a clear image of the letter "y" can be seen.

[0072] like Figure 5 (a) to (d) show the far-field test environment and schematic diagrams of the processed samples of Example I. Figure 5 (a) and (b) show the radiation and reflection far-field test scenarios, respectively. In the radiation test scenario, the metasurface and receiving horn antenna are connected to the two ports of the vector network analyzer. In the reflection test scenario, the circularly polarized feed and receiving horn antenna are connected to the two ports of the vector network analyzer. The circularly polarized feed is placed 96 mm from the metasurface. Figure 5 (c) and (d) show the front and back views of Example I. The size of the metasurface prototype is 192×192 mm. 2 .

[0073] like Figure 6 (a) to (d) show the far-field functional test results. "Mea." indicates test results, and "Sim." indicates simulation results. Figure 6 (a) compares the simulation and test S of the metasurface 11 , in the range of 8.1 to 11.2 GHz, S 11 It is suppressed below -10dB, showing good impedance matching performance. Figure 6 Panel (b) shows the normalized far-field pattern of left-hand circularly polarized radiation at 10.3 GHz. The two beams tested were pointed at (19°, 0°) and (-28°, 0°), respectively, with a gain difference of ΔG of 5.3 dB. The maximum angular deviation between the two beams was 2°, and the test results were consistent with the simulation results. Figure 6 (c) further shows the simulated and tested gain and axial ratio of the two beams. After testing, the maximum gain of the two beams are 19.91dBic and 25.06dBic, respectively, and the corresponding aperture efficiencies are 9.35% and 30%, respectively. In the range of 9.9-10.8GHz, the measured axial ratios of the two beams are less than 3dB. The test results are consistent with the simulation results. In addition, Figure 6As shown in (d), the metasurface's co-polarized and cross-polarized RCS reductions were also tested under illumination by a right-handed circularly polarized plane wave and compared with simulation results. Because the geometric phase only responds to the co-polarized component of the reflected wave, the co-polarized wave scatters in all directions. For cross-polarized waves, the RCS reduction primarily stems from the low cross-polarization amplitude of the metasurface's elements. The tested RCS reductions for both co-polarized and cross-polarized waves are consistent with the simulation results.

[0074] like Figure 7 (a) to (d) show the near-field test environment and schematic diagrams of the processed samples of Example V. Figure 7 (a) and (b) show the radiated and reflected near-field test scenarios, respectively. In the radiated test scenario, the metasurface and probe are connected to the two ports of a vector network analyzer. In the reflected test scenario, the circularly polarized feed and probe are connected to the two ports of the vector network analyzer. The imaging plane is set at 180 mm from the metasurface. Figure 7 (c) and (d) show the front view and back view of Example V.

[0075] like Figure 8 (a) to (c) show schematic diagrams of near-field functional test results. Figure 8 (a) compares the simulation and test S of the metasurface 11 , near the operating frequency of 10.3GHz, S 11 It is suppressed below -10dB, showing good impedance matching performance. Figure 8 Panels (b) and (c) show the test results of the radiated and reflected near fields, where the letters "y" and "L" can be clearly observed. Further calculations show that the correlation coefficients between the measured and target images are 82.28% and 70.31%, respectively, indicating good agreement between the measured and simulated results.

[0076] The antenna described in the present invention includes the circularly polarized multiplexing metasurface that integrates and controls radiation waves and reflected waves.

[0077] The communication device described in the present invention includes the circularly polarized multiplexing metasurface that integrates and controls the radiated waves and the reflected waves.

[0078] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A circularly polarized multiplexing metasurface that integrates and controls radiation waves and reflected waves, characterized in that: The metasurface is composed of metasurface units periodically arranged along the x and y directions. The metasurface units include, from top to bottom, a patch layer, a first dielectric substrate, an isolation ground, an adhesive layer, a second dielectric substrate, and a phase delay layer. The patch layer includes a left-handed circularly polarized patch resonator and a peripheral hole-filled quadrilateral ring structure. A second metal through-hole is provided at the center of the metasurface unit, penetrating all layers. The patch resonator and the phase delay layer are connected through the second metal through-hole, so that electromagnetic energy is transmitted from the phase delay layer to the patch resonator. The geometric phase of the reflected wave and the radiated wave is controlled by the rotation angle of the patch resonator, and the transmission phase of the radiated wave is controlled by the delay line length of the phase delay layer. When the patch resonator is excited by the guided wave, the metasurface unit will radiate left-handed circularly polarized waves; when the right-handed circularly polarized waves hit the metasurface unit, the electromagnetic energy cannot be received and is still reflected back into the free space in the form of right-handed circularly polarized waves.

2. The circularly polarized multiplexing metasurface for integrated control of radiation waves and reflected waves according to claim 1, characterized in that: The through holes on the perforated quadrilateral ring structure are arranged in a ring shape. The first dielectric substrate is provided with first metal through holes matching the through holes on the perforated quadrilateral ring structure, and the isolation ground is provided with through holes matching the first metal through holes.

3. The circularly polarized multiplexing metasurface for integrated control of radiation waves and reflected waves according to claim 1, characterized in that: The patch resonator is an irregular octagonal metal patch structure etched with a rectangular through hole, and the center of the rectangular through hole deviates from the center of the metasurface unit.

4. The circularly polarized multiplexing metasurface for integrated control of radiation waves and reflected waves according to claim 3, characterized in that: The irregular octagonal metal patch structure is based on a square structure with a side length of a. Two sets of diagonals are cut according to the set size, and one set of diagonals is cut off with a right angle side of t. a The isosceles right triangle, the other set of diagonals cut off the right angle side is t b An isosceles right triangle.

5. The circularly polarized multiplexing metasurface for integrated control of radiation waves and reflected waves according to claim 1, characterized in that: The phase delay layer is a phase delay line, one end of which is located at the center of the metasurface unit. Different lengths of the phase delay line correspond to different transmission phases.

6. The circularly polarized multiplexing metasurface for integrated control of radiation waves and reflected waves according to claim 1, characterized in that: The isolation ground is used to isolate the mutual coupling between the patch resonator and the phase delay layer.

7. The circularly polarized multiplexing metasurface for integrated control of radiation waves and reflected waves according to claim 1, characterized in that: The rotation angle of the patch resonator of each metasurface unit in the metasurface is independently controlled.

8. The circularly polarized multiplexing metasurface for integrated control of radiation waves and reflected waves according to claim 1, characterized in that: When the metasurface unit is illuminated by a right-handed circularly polarized wave, the reflected wave Expressed as: Among them, J lin (α) is the linear basis vector Jones matrix of the patch resonator rotated α degrees, α is the rotation angle of the patch resonator, is the incident electric field, E0 is the electric field amplitude, For a right-hand circularly polarized wave propagating in the +z direction, the phase of the reflected wave will lead by 2α; When the patch resonator is excited by a guided wave transmitted through a phase delay line, a left-handed circularly polarized wave will be radiated directly from the metasurface unit into the free space, expressed as: in, is the electric field of the radiation wave, is a left-hand circularly polarized wave propagating in the +z direction, and β is the transmission phase introduced by the phase delay line. After the same rotation operation, the radiated wave is rewritten as: in, is the electric field of the radiated wave after rotating the patch resonator by α degrees, and M(-α) is the rotation matrix of rotating the patch resonator by -α degrees; then the phase of the left-hand circularly polarized radiated wave will advance by -α+β, and the phase responses of the reflected wave and the radiated wave will be decoupled.

9. An antenna, characterized in that: A circularly polarized multiplexing metasurface for integrating and controlling radiation waves and reflected waves as described in any one of claims 1 to 7.

10. A communication device, characterized in that: A circularly polarized multiplexing metasurface for integrating and controlling radiation waves and reflected waves as described in any one of claims 1 to 7.

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