Metasurface, metasurface design method and antenna

Abstract

The invention relates to a metasurface, a metasurface design method and an antenna. The metasurface comprises a plurality of metasurface units which are uniformly arranged; the metasurface unit comprises a dielectric plate and metal layers pressed on the two sides of the dielectric plate. The metal layer comprises a metal square ring, a single-side open circular ring, a double-side open circular ring and a circular patch; the circle centers of the single-edge-opened circular ring, the double-edge-opened circular ring and the circular patch are the same and coincide with the geometric center of the metal square ring; the inner diameter of the double-edge opening ring is larger than the diameter of the circular patch, the outer diameter of the double-edge opening ring is smaller than the inner diameter of the single-edge opening ring, and the outer diameter of the single-edge opening ring is smaller than the side length of an inner frame of the metal square ring; the first opening and the second opening of the double-side opening circular ring are the same in shape and opposite in opening direction. The radio frequency identification reader-writer comprises the carrier suppression circuit. According to the invention, diffraction-free Bessel beams can be generated by using resources of a whole space, and left-hand circular polarization and right-hand circular polarization of the Bessel beams can be independently regulated and controlled.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a metasurface, a metasurface design method and an antenna. Background Art

[0002] Orbital Angular Momentum (OAM), as a new degree of freedom for controlling electromagnetic waves, has become a research hotspot because it can increase the capacity and efficiency of channels to an exponential level. Currently, there are schemes such as spiral phase plates, reflector antennas, uniform circular arrays, and metasurfaces to generate vortex electromagnetic waves with OAM to meet the current needs of wireless communications.

[0003] However, the inherent divergence angle of OAM limits its application in long-distance communications. High-order Bessel beams carrying OAM are one of the solutions to the above-mentioned divergence angle problem due to their special non-diffraction characteristics. Metasurfaces can be used to generate Bessel beams due to their planar structure, cost-effectiveness and precise modulation of electromagnetic waves, but traditional metasurfaces only use half-space to generate vortex electromagnetic waves in the reflection or transmission direction, resulting in a great waste of space resources. Summary of the invention

[0004] Based on this, it is necessary to provide a metasurface, a metasurface design method and an antenna that can utilize the resources of the entire space to generate Bessel waves.

[0005] In a first aspect, in one embodiment, the present application provides a metasurface, comprising a plurality of metasurface units arranged uniformly; the metasurface unit comprises a dielectric plate and a metal layer pressed on both sides of the dielectric plate; the metal layer comprises a metal square ring, a single-sided open circular ring, a double-sided open circular ring and a circular patch;

[0006] The centers of the single-sided open circular ring, the double-sided open circular ring and the circular patch are the same, and the centers coincide with the geometric center of the metal square ring;

[0007] The inner diameter of the double-sided open ring is larger than the diameter of the circular patch, the outer diameter of the double-sided open ring is smaller than the inner diameter of the single-sided open ring, and the outer diameter of the single-sided open ring is smaller than the side length of the inner frame of the metal square ring;

[0008] The first opening of the double-sided open circular ring and the second opening of the double-sided open circular ring have the same shape and opposite opening directions.

[0009] In one embodiment, the direction of the first opening is parallel to the opening direction of the single-sided opening circular ring.

[0010] In one embodiment, there is a positive correlation between the opening width of the single-sided opening circular ring and the opening width of the first opening.

[0011] In one embodiment, the positive correlation is a positive proportional relationship.

[0012] In one embodiment, the metal material used for the metal layer includes copper.

[0013] In a second aspect, in one embodiment, the present application provides a metasurface design method, which is applied to a metasurface; the metasurface includes a plurality of metasurface units arranged uniformly; the metasurface unit includes a dielectric plate and a metal layer pressed on both sides of the dielectric plate; the metal layer includes a metal square ring, a single-sided open circular ring, a double-sided open circular ring and a circular patch; the centers of the single-sided open circular ring, the double-sided open circular ring and the circular patch are the same, and the centers coincide with the geometric centers of the metal square rings; the inner diameter of the double-sided open circular ring is greater than the diameter of the circular patch, the outer diameter of the double-sided open circular ring is smaller than the inner diameter of the single-sided open circular ring, and the outer diameter of the single-sided open circular ring is smaller than the inner frame side length of the metal square ring; the first opening of the double-sided open circular ring is the same as the second opening of the double-sided open circular ring, and the opening directions are opposite; the method includes:

[0014] A left-hand circularly polarized electromagnetic wave and a right-hand circularly polarized electromagnetic wave are vertically incident on the geometric center of the metasurface using a feed source;

[0015] Determining the opening direction of the first opening of each metasurface unit according to the circular polarization phase of the target Bessel beam in the full space of the metasurface; the full space includes a half space in the reflection direction of the metasurface and a half space in the transmission direction of the metasurface;

[0016] Acquire a compensation phase of the metasurface, and determine an opening width of a first opening of each metasurface unit on the metasurface according to the compensation phase;

[0017] Based on the opening directions and opening widths of the first openings of all the metasurface units on the metasurface, a target metasurface for generating a target Bessel beam is acquired.

[0018] In one of the embodiments, determining the opening direction of the first opening of each metasurface unit according to the circular polarization phase of the target Bessel beam in the whole space of the metasurface includes:

[0019] According to the following rotation angle function relationship, the direction of the first opening of each supersurface unit on the supersurface is obtained:

[0020]

[0021]

[0022]

[0023] in, is the right-hand circular polarization phase of the target Bessel beam, is the left-hand circular polarization phase of the target Bessel beam, is the linear polarization phase difference of the target Bessel beam, is the rotation angle of the first opening of the metasurface unit.

[0024] In one embodiment, obtaining a compensation phase of a metasurface includes:

[0025] According to the compensation phase function, the compensation phase is obtained:

[0026]

[0027]

[0028]

[0029]

[0030] in, is the phase compensation required to convert a spherical wave into a plane wave, is the phase required to compensate for the deflected beam, is the phase required to generate the Bessel beam, is the wave vector in free space, is the distance between the geometric center of the metasurface and the feed, is the z-axis coordinate of the feed, is the pitch angle of the deflected beam on the metasurface, is the azimuth of the deflected beam, is the convergence angle of the Bessel beam, is the mode of the vortex beam, is the coordinate value of each hypersurface unit, is the wavelength in free space, is the wavelength of the operating frequency, and is the location index of each hypersurface unit, is the compensation phase.

[0031] In one embodiment, determining the opening width of the first opening of each metasurface unit on the metasurface according to the compensation phase includes:

[0032] Based on the compensation phase, the width of the first opening of each metasurface unit is scanned and optimized through simulation software to select the size of the width of the first opening of each metasurface unit.

[0033] In the third aspect, in one embodiment, the present application provides an antenna, comprising a metasurface as described in any embodiment of the first aspect and a feed source arranged directly above the geometric center of the metasurface; the feed source comprises a circularly polarized horn for vertically incident left-handed circularly polarized electromagnetic waves and right-handed circularly polarized electromagnetic waves onto the metasurface.

[0034] The above-mentioned metasurface, metasurface design method and antenna, the metasurface unit of the metasurface includes a dielectric plate and a metal layer pressed on both sides of the dielectric plate, and the metal layer includes a metal square ring, a single-sided open circular ring, a double-sided open circular ring and a circular patch; the center of the single-sided open circular ring, the double-sided open circular ring and the circular patch is the same, and the center of the circle coincides with the geometric center of the metal square ring; the inner diameter of the double-sided open circular ring is larger than the diameter of the circular patch, the outer diameter of the double-sided open circular ring is smaller than the inner diameter of the single-sided open circular ring, and the outer diameter of the single-sided open circular ring is smaller than the inner length of the inner frame of the metal square ring; the first opening of the double-sided open circular ring and the second opening of the double-sided open circular ring have the same shape and opposite opening directions. Based on the structure of the above-mentioned metasurface, the present application can utilize the resources of the entire space to generate a diffraction-free Bessel beam, and independently control the left-handed circular polarization and the right-handed circular polarization of the outgoing Bessel beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A schematic diagram of a super surface structure in an embodiment;

[0037] Figure 2 is a schematic diagram of a three-dimensional structure of a super surface unit in one embodiment;

[0038] Figure 3 is a schematic diagram of a planar structure of a super surface unit in one embodiment;

[0039] Figure 4 A schematic diagram of the annotation of various parameters of a super surface unit in an embodiment;

[0040] Figure 5 A 3D simulation diagram of vortex electromagnetic waves emitted by a metasurface in the entire space and a diagram of the electric field phase and amplitude results in one embodiment;

[0041] Figure 6 A schematic diagram of a curve of the reflection coefficient (a) and the transmission coefficient (a) of a metasurface under circularly polarized incidence conditions in one embodiment;

[0042] Figure 7 1 is an amplitude characteristic (a) and a phase characteristic (b) of a metasurface unit in a reflection direction in an embodiment;

[0043] Figure 8 1 is an amplitude characteristic (a) and a phase characteristic (b) of a metasurface unit in a transmission direction in an embodiment;

[0044] Fig. 9 Schematic diagram of the process of a super surface design method in one embodiment. DETAILED DESCRIPTION

[0045] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0047] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0048] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least a portion of an element” means a part or all of an element.

[0049] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0050] Orbital Angular Momentum (OAM), as a new degree of freedom for controlling electromagnetic waves, has become a hot topic of research because it can significantly increase channel capacity and efficiency to an exponential level. In traditional technologies, spiral phase plates, reflector antennas, uniform circular arrays, and metasurfaces can be used to generate vortex electromagnetic waves to meet the needs of wireless communication.

[0051] Metasurfaces are used to generate Bessel beams due to their planar structure, cost-effectiveness, and precise modulation of electromagnetic waves. However, the inherent divergence angle of OAM limits its practical application in long-distance communications. High-order Bessel beams carrying OAM can be used as one of the solutions to solve the above technical problems due to their special non-diffraction characteristics.

[0052] In the literature of the prior art, the document “YANG Y, ZHU Y, XIE W, BU L, ZANG Y, LIU X. High-efficiency ultrathin metasurfaces with simultaneous control of complete phase, amplitude, and polarization [J]. Optics Express, 2023, 31(2) :3134-3142.” uses a single-layer transmission plate to achieve independent control of amplitude and phase, but its total profile height is only 4.6 , but the diffraction-free distance only reaches 37.4 ;

[0053] The paper "WU S, ZHANG Y, CUI X, et al. Generation of dual-polarizationorbital angular momentum vortex beams with reflection-type metasurface[J].Optics Communications, 2024, 553: 130107." uses a reflective anisotropic metasurface to generate single-beam, multi-beam and different-mode vortex electromagnetic waves;

[0054] The paper "DING G, CHEN S, LUO XY, et al. Ultrathin Single-Substrate Pancharatnam-Berry Phase Metasurface with High Transmission Efficiency[J].IEEE Transactions on Antennas and Propagation, 2023: 1-1." uses an ultrathin PB-type transmission metasurface and applies the Huygens principle to expand the bandwidth of vortex electromagnetic waves.

[0055] Based on the above literature, in order to further utilize the new degrees of freedom provided by orbital angular momentum to improve communication capacity, the problem of hollowness generated by the metasurface needs to be solved urgently: the energy distribution of the Bessel beam generated by the traditional metasurface will be ring-shaped, and the energy in the central area is zero, forming a "hollow area" of energy distribution. In addition, the metasurface in traditional technology only uses the resources of half space to generate reflected or transmitted vortex electromagnetic waves, resulting in a huge waste of space resources.

[0056] In order to solve the above problems, the present application provides a metasurface, a metasurface design method and an antenna that can generate Bessel waves using resources in the entire space.

[0057] The metasurface in the present application can be applied to antennas or devices with antennas, that is, antennas or antenna arrays designed based on any metasurface provided in the present application can be applied to transmitters or receivers. For example, the transmitter or receiver adopts a system based on a reflector antenna or a lens antenna: the transmitter and the receiver can be a wireless base station or a relay station; the receiver can be a terminal. For example, the transmitter includes a transmission signal source, a power amplifier (PA), a feed antenna, and an antenna array of a metasurface. For example, a carrier signal is emitted by the transmission signal source in the transmitter and hits the electromagnetic metasurface antenna array. At the same time, the transmitter calculates the phase information corresponding to the maximum gain of the transceiver antenna, and dynamically adjusts the equivalent circuit impedance of the antenna array unit of the metasurface antenna array according to the calculation result, thereby phase modulating the incident carrier signal and reflecting and transmitting it.

[0058] When the solution of the embodiment of the present application is applied to a wireless access network device, the wireless access network device can be a base transceiver station (BTS) in a global system for mobile communications (GSM) or a code division multiple access (CDMA) network, a node base station (NB) in a wideband code division multiple access (WCDMA), an evolutionary NB (eNB or eNodeB) in a long term evolution (LTE), a wireless controller in a cloud radio access network (CRAN) scenario, a base station in a 5G mobile communication system or a new generation of wireless (NR) communication system, or a base station in a future mobile communication system, an access node in a WiFi system, a device that performs base station functions in device-to-device (D2D) communication and machine communication, an access network device in a future evolved PLMN network, or a vehicle networking device, etc. The embodiment of the present application does not limit the specific technology and specific device form adopted by the wireless access network device. In the embodiments of the present application, the terms 5G and NR may be equivalent.

[0059] When the solution of the embodiments of the present application is applied to a terminal device, the terminal device may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, and the like.

[0060] In one embodiment, Figure 1 As shown, the present application provides a metasurface 10, comprising a plurality of metasurface units 100 arranged uniformly. Figure 2The metasurface unit 100 includes a dielectric plate and metal layers laminated on both sides of the dielectric plate. Figure 3 The metal layer includes a metal square ring 102 , a single-sided open circular ring 104 , a double-sided open circular ring 106 and a circular patch 108 .

[0061] Among them, the centers of the single-sided open circular ring 104, the double-sided open circular ring 106 and the circular patch 108 are the same, and the centers coincide with the geometric center of the metal square ring 102; the inner diameter of the double-sided open circular ring 106 is larger than the diameter of the circular patch 108, the outer diameter of the double-sided open circular ring 106 is smaller than the inner diameter of the single-sided open circular ring 104, and the outer diameter of the single-sided open circular ring 104 is smaller than the inner frame side length of the metal square ring 102; the first opening of the double-sided open circular ring 106 and the second opening of the double-sided open circular ring 106 have the same shape and opposite opening directions.

[0062] Among them, the metal layer composed of the metal square ring 102, the single-sided open circular ring 104, the double-sided open circular ring 106 and the circular patch 108 can expand the bandwidth of the metasurface 10. Exemplarily, the single-sided open circular ring 104 and the double-sided open circular ring 106 can be a single-sided open circular resonant ring and a double-sided open circular resonant ring. Optionally, the dielectric plate of the metasurface unit 100 can adopt a F4BM2-2 dielectric plate, and the thickness of the dielectric plate can be set according to application requirements.

[0063] In practical applications, such as Figure 1 As shown, a feed source 20 may be disposed above the metasurface 10, and the feed source 20 is used to vertically irradiate left-hand circularly polarized electromagnetic waves and right-hand circularly polarized electromagnetic waves onto the metasurface 10, so that the metasurface 10 generates a required Bessel beam accordingly.

[0064] Specifically, the embodiment of the present application can achieve spin decoupling by setting the arrangement of the metal patches of the metasurface unit 100 and the size of the metal layer structure (metal square ring 102, single-sided open circular ring 104, double-sided open circular ring 106 and circular patch 108), thereby utilizing spin decoupling to achieve independent control of the two handed circular polarizations of the target Bessel beam generated by the metasurface 10.

[0065] By using the above-mentioned metasurface 10, a vortex electromagnetic wave with mode 1 in both the reflection and transmission directions can be generated, and since the metasurface 10 generates a Bessel beam, the problem of OAM divergence angle can be solved to a certain extent. In addition, the metasurface 10 of the embodiment of the present application can generate beams in two directions, making full use of the resources of the entire space, and can keep the amplitude of reflection and transmission basically consistent (about 0.5) at 7-10GHz, and make the phase meet 360° coverage, which can effectively solve the hollow problem that is difficult to handle with the traditional metasurface 10.

[0066] In one embodiment, the direction of the first opening is parallel to the opening direction of the single-sided opening ring 104 .

[0067] The direction of the first opening of the double-sided open ring 106 can affect the geometric phase of the target Bessel wave generated by the metasurface 10 .

[0068] Specifically, the opening directions of the first opening, the second opening and the single-sided opening ring 104 of the double-sided opening ring 106 of the metasurface unit 100 remain parallel in the same plane, that is, when the rotation angle of any of the above openings is the same as the rotation angle of the other openings.

[0069] In one embodiment, there is a positive correlation between the opening width of the single-sided opening ring 104 and the opening width of the first opening.

[0070] Among them, the opening width of the first opening of the double-sided open ring 106 and the opening width of the single-sided open ring 104 can affect the propagation phase of the target Bessel wave generated by the metasurface 10.

[0071] In one embodiment, the positive correlation is a positive proportional relationship.

[0072] For example, the ratio of the opening width of the first opening of the double-sided opening circular ring 106 to the opening width of the single-sided opening circular ring 104 may be 1.2.

[0073] It can be understood that the ratio between the opening width of the first opening of the above-mentioned double-sided open ring 106 and the opening width of the single-sided open ring 104 is not limited to the implementation method mentioned in the above-mentioned embodiment. The embodiment of the present application does not specifically limit the ratio between the opening width of the first opening of the double-sided open ring 106 and the opening width of the single-sided open ring 104.

[0074] In one embodiment, the metal material used for the metal layer includes copper.

[0075] In order to make the technical solutions and structures of the embodiments of the present application clearer, Figure 4 The present application provides an exemplary structure of the metal layer of the super surface unit 100, and further describes the present application in detail. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0076] In one possible implementation, see Figure 4 As shown, the key parameters of the metal layer of the metasurface unit 100 are shown in Table 1 below:

[0077] Table 1

[0078]

[0079] Among them, p is the unit size width of the super surface unit 100, h is the unit thickness of the super surface unit 100 (not shown in the figure), r1 is the radius of the circular patch 108, r2 is the outer diameter of the double-sided open ring 106, r3 is the inner diameter of the single-sided open ring 104, r4 is the outer diameter of the single-sided open ring 104, r5 is the inner diameter of the double-sided open ring 104, x1 is the opening depth (including the first opening and the second opening) of the double-sided open ring 106, x2 is the opening depth of the single-sided open ring 104, y1 is the opening width of the second opening of the double-sided open ring 106 (the numerical value is the same as the opening width of the first opening), y2 is the opening width of the single-sided open ring 104, and t is the frame width of the metal square ring 102. In addition, Figure 4 The opening direction (ie, the rotation angle α) of the first opening of the double-sided opening circular ring 106 is 90°.

[0080] Based on the structure of the metasurface 10 of the metasurface unit 100, the feed source 20 can be used to vertically incident left-handed circularly polarized and right-handed circularly polarized electromagnetic waves on the metasurface 10, and the following can be obtained: Figure 5 The 3D simulation diagram of the full-space vortex electromagnetic wave emitted by the metasurface 10 structure and the electric field phase and amplitude result diagram of the Bessel beam are shown.

[0081] Furthermore, based on the structure of the super surface 10 of the super surface unit 100, the following can be obtained: Figure 6 The reflection coefficient of the metasurface 10 shown in FIG. 1 under circularly polarized incidence is ( Figure 6 a) and the transmission coefficient ( Figure 6 b). Optionally, the feed source 20 may be a circularly polarized horn.

[0082] In some examples, such as Figure 7 and Figure 8 As shown, based on the metasurface structure of the metasurface unit 100, according to the opening direction of the first opening of the double-sided open ring 106 (i.e., the rotation angle α), the reflection of the metasurface unit 100 can also be obtained ( Figure 7 a) Amplitude characteristics and ( Figure 7 b) phase characteristics, and the transmission ( Figure 8 a) Amplitude characteristics and ( Figure 8 b) Phase characteristics.

[0083] In one embodiment, Fig. 9As shown, the present application provides a metasurface design method, which is applied to a metasurface; the metasurface includes a plurality of metasurface units arranged evenly; the metasurface unit includes a dielectric plate and a metal layer pressed on both sides of the dielectric plate; the metal layer includes a metal square ring, a single-sided open circular ring, a double-sided open circular ring and a circular patch; the centers of the single-sided open circular ring, the double-sided open circular ring and the circular patch are the same, and the centers coincide with the geometric centers of the metal square rings; the inner diameter of the double-sided open circular ring is greater than the diameter of the circular patch, the outer diameter of the double-sided open circular ring is smaller than the inner diameter of the single-sided open circular ring, and the outer diameter of the single-sided open circular ring is smaller than the inner frame side length of the metal square ring; the first opening of the double-sided open circular ring is the same as the second opening of the double-sided open circular ring in shape and the opening directions are opposite; the method includes the following steps:

[0084] Step S902, using a feed source to vertically incident left-handed circularly polarized electromagnetic waves and right-handed circularly polarized electromagnetic waves directly above the geometric center of the metasurface.

[0085] Exemplarily, the feed source may include a circularly polarized horn disposed above the metasurface; the direction of the first opening is parallel to the opening direction of the unilateral opening circular ring; and the opening width of the unilateral opening circular ring is in direct proportion to the opening width of the first opening.

[0086] Step S904, determining the opening direction of the first opening of each metasurface unit according to the circular polarization phase of the target Bessel beam in the entire space of the metasurface.

[0087] The full space includes the half space in the reflection direction of the metasurface and the half space in the transmission direction of the metasurface. The target Bessel beam is the Bessel beam that is finally emitted by the required metasurface and meets the communication performance requirements, which can solve the problem of OAM divergence angle to a certain extent.

[0088] Specifically, since the direction of the first opening of the double-sided open ring of the metasurface unit can affect the geometric phase of the target Bessel wave generated by the metasurface, the embodiment of the present application can determine the opening direction (i.e., the rotation angle) of the first opening of each metasurface unit on the metasurface according to the required circular polarization phase of the target Bessel beam, and then the opening direction of the second opening and the opening direction of the single-sided open ring can also be determined according to the opening direction of the first opening.

[0089] Step S906, obtaining a compensation phase of the metasurface, and determining an opening width of a first opening of each metasurface unit on the metasurface according to the compensation phase.

[0090] Among them, the opening width of the first opening of each metasurface unit can affect the propagation phase of the target Bessel wave generated by the metasurface.

[0091] Specifically, the metasurface used for phase modulation also needs to perform corresponding phase compensation. The required compensation phase includes: the compensation phase required to convert the spherical wave into a plane wave , the phase required to deflect the beam and the phase required to generate the Bessel beam .

[0092] Step S908: acquiring a target metasurface for generating a target Bessel beam based on the opening directions and opening widths of the first openings of all metasurface units on the metasurface.

[0093] Specifically, when the opening direction and opening width of the first opening of all the supersurface units on the supersurface are determined, the structural settings and direction settings of each supersurface unit can be determined, so that the target supersurface that can generate the required target Bessel beam can be determined. The structural parameters and performance parameters of the target supersurface can refer to the embodiments described above, and will not be repeated here.

[0094] In one of the embodiments, in step S904, determining the opening direction of the first opening of each metasurface unit according to the circular polarization phase of the target Bessel beam in the whole space of the metasurface specifically includes:

[0095] According to the rotation angle function relationship shown in the following formulas 1 to 3, the direction of the first opening of each supersurface unit on the supersurface is obtained:

[0096] (Formula 1)

[0097] (Formula 2)

[0098] (Formula 3)

[0099] in, is the right-hand circular polarization phase of the target Bessel beam, is the left-hand circular polarization phase of the target Bessel beam, is the linear polarization phase difference of the target Bessel beam, is the rotation angle of the first opening of the metasurface unit.

[0100] Specifically, the opening direction (i.e., the rotation angle α) of the first opening of each metasurface unit can be determined according to the right-handed circular polarization phase and the left-handed circular polarization phase of the desired target Bessel beam. Based on the structural setting and direction setting of the above-mentioned metasurface unit, the embodiment of the present application utilizes circular polarization spin decoupling to achieve independent control of two handed circular polarizations.

[0101] In some examples, when the opening directions of the first opening, the second opening and the single-sided opening ring of the double-sided opening ring of the metasurface unit remain parallel in the same plane, the rotation angles of the first opening, the second opening and the opening of the single-sided opening ring are the same; for example, Figure 4 As shown, at this time, the rotation angle α of the first opening of the double-sided opening circular ring is 90°, and the opening directions of the second opening and the single-sided opening circular ring are parallel to the first opening.

[0102] In one embodiment, obtaining a compensation phase of a metasurface, and determining an opening width of a first opening of each metasurface unit on the metasurface according to the compensation phase, comprises the following steps:

[0103] According to the compensation phase function described in the following formula 4 to formula 7, the compensation phase is obtained:

[0104] (Formula 4)

[0105] (Formula 5)

[0106] (Formula 6)

[0107] (Formula 7)

[0108] in, is the phase compensation required to convert a spherical wave into a plane wave, is the phase required to compensate for the deflected beam, is the phase required to generate the Bessel beam, is the wave vector in free space, is the distance between the geometric center of the metasurface and the feed, is the z-axis coordinate of the feed, is the pitch angle of the deflected beam on the metasurface, is the azimuth of the deflected beam, is the convergence angle of the Bessel beam, is the mode of the vortex beam, is the coordinate value of each hypersurface unit, is the wavelength in free space, is the wavelength of the operating frequency, and is the location index of each hypersurface unit, is the compensation phase.

[0109] In one embodiment, in step S906, determining the opening width of the first opening of each metasurface unit on the metasurface according to the compensation phase specifically includes:

[0110] Based on the compensation phase, the width of the first opening of each metasurface unit is scanned and optimized through simulation software to select the size of the width of the first opening of each metasurface unit.

[0111] Specifically, based on the calculated compensation phase, simulation software can be used to scan and optimize the width of the opening of each metasurface unit on the metasurface, so that the width of the opening of the metasurface unit can meet the structural requirements of the compensation phase, thereby selecting the width of the first opening of each metasurface unit (i.e., the y1 parameter in Table 1).

[0112] In one embodiment, the present application provides an antenna, comprising a metasurface as described in any one of the above embodiments.

[0113] In one of the embodiments, it also includes a feed source arranged directly above the geometric center of the metasurface.

[0114] Exemplarily, the feed source can be used to vertically incident left-handed circularly polarized electromagnetic waves and right-handed circularly polarized electromagnetic waves onto the metasurface. Optionally, the feed source includes a circularly polarized horn. The above antenna has a simple structure, no complex feeding structure, and can be manufactured using PCB technology. It can also be applied to multiple frequency bands and has good economic applicability.

[0115] In one embodiment, the present application provides a communication device, comprising the antenna as described in any one of the above embodiments.

[0116] In an exemplary embodiment, the present application provides an electronic device, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0117] In one embodiment, the present application provides a computer program product, including a computer program, which implements the steps in the above-mentioned method embodiments when executed by a processor.

[0118] In one embodiment, the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0119] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0120] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0121] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A metasurface, characterized in that: It comprises a plurality of evenly arranged metasurface units; the metasurface unit comprises a dielectric plate and a metal layer pressed on both sides of the dielectric plate; the metal layer comprises a metal square ring, a single-sided open circular ring, a double-sided open circular ring and a circular patch; The centers of the single-sided open circular ring, the double-sided open circular ring and the circular patch are the same, and the centers coincide with the geometric center of the metal square ring; The inner diameter of the double-sided open circular ring is larger than the diameter of the circular patch, the outer diameter of the double-sided open circular ring is smaller than the inner diameter of the single-sided open circular ring, and the outer diameter of the single-sided open circular ring is smaller than the side length of the inner frame of the metal square ring; The first opening of the double-sided open circular ring and the second opening of the double-sided open circular ring have the same shape and opposite opening directions.

2. The supersurface according to claim 1, characterized in that The direction of the first opening is parallel to the opening direction of the single-sided opening circular ring.

3. The supersurface according to claim 1, characterized in that There is a positive correlation between the opening width of the single-sided opening circular ring and the opening width of the first opening.

4. The supersurface according to claim 3, characterized in that The positive correlation is a positive proportional relationship.

5. The supersurface according to any one of claims 1 to 4, characterized in that: The metal material used for the metal layer includes copper.

6. A super surface design method, characterized in that: Applied to a metasurface; the metasurface comprises a plurality of metasurface units arranged evenly; the metasurface unit comprises a dielectric plate and a metal layer pressed onto both sides of the dielectric plate; the metal layer comprises a metal square ring, a single-sided open circular ring, a double-sided open circular ring and a circular patch; the centers of the single-sided open circular ring, the double-sided open circular ring and the circular patch are the same, and the centers coincide with the geometric centers of the metal square rings; the inner diameter of the double-sided open circular ring is greater than the diameter of the circular patch, the outer diameter of the double-sided open circular ring is smaller than the inner diameter of the single-sided open circular ring, and the outer diameter of the single-sided open circular ring is smaller than the inner frame side length of the metal square ring; the first opening of the double-sided open circular ring is the same shape as the second opening of the double-sided open circular ring, and the opening directions are opposite; The method comprises: Using a feed source to vertically incident a left-hand circularly polarized electromagnetic wave and a right-hand circularly polarized electromagnetic wave directly above the geometric center of the metasurface; Determining the opening direction of the first opening of each of the metasurface units according to the circular polarization phase of the target Bessel beam in the full space of the metasurface; the full space includes a half space in the reflection direction of the metasurface and a half space in the transmission direction of the metasurface; Acquire a compensation phase of the metasurface, and determine an opening width of the first opening of each of the metasurface units on the metasurface according to the compensation phase; Based on the opening directions and opening widths of the first openings of all the metasurface units on the metasurface, a target metasurface for generating the target Bessel beam is acquired.

7. The method according to claim 6, characterized in that Determining the opening direction of the first opening of each of the metasurface units according to the circular polarization phase of the target Bessel beam in the full space of the metasurface includes: According to the following rotation angle function relationship, the direction of the first opening of each of the super surface units on the super surface is obtained: in, is the right-hand circular polarization phase of the target Bessel beam, is the left-hand circular polarization phase of the target Bessel beam, is the linear polarization phase difference of the target Bessel beam, is the rotation angle of the first opening of the super surface unit.

8. The method according to claim 6, characterized in that Obtaining a compensation phase of the metasurface, comprising: According to the compensation phase function, the compensation phase is obtained: in, is the phase compensation required to convert a spherical wave into a plane wave, is the phase required to compensate for the deflected beam, is the phase required to generate the Bessel beam, is the wave vector in free space, is the distance between the geometric center of the metasurface and the feed, is the z-axis coordinate of the feed, is the pitch angle of the deflected beam on the metasurface, is the azimuth angle of the deflected beam, is the convergence angle of the Bessel beam, is the mode of the vortex beam, is the coordinate value of each of the hypersurface units, is the wavelength in free space, is the wavelength of the operating frequency, and is the positioning index of each of the metasurface units, is the compensation phase.

9. The method according to claim 6, characterized in that Determining the opening width of the first opening of each of the metasurface units on the metasurface according to the compensation phase includes: Based on the compensation phase, the width of the first opening of each of the metasurface units is scanned and optimized by simulation software to select the size of the width of the first opening of each of the metasurface units.

10. An antenna, characterized in that: It comprises a metasurface as described in any one of claims 1 to 5 and a feed source arranged directly above the geometric center of the metasurface; the feed source comprises a circularly polarized horn for vertically incident left-handed circularly polarized electromagnetic waves and right-handed circularly polarized electromagnetic waves on the metasurface.

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