Reconfigurable intelligent surface

Abstract

A reconfigurable intelligent surface. The reconfigurable intelligent surface comprises a three-layer structure, comprising an artificial microstructure array capable of reflection and transmission within a specific frequency band range. By applying an external voltage to control the on / off of a semiconductor switch, an original phase shift structure is changed, ultimately achieving phase control of reflection and transmission. In addition, the structure is simple, can be realized by a microfabrication means, involves a mature process, and is easy to implement in high-frequency bands such as millimeter-wave and terahertz bands.

Description

A reconfigurable smart metasurface

[0001] This application claims priority to the Chinese patent application with application number 202410390581.8 filed with the State Intellectual Property Office of China on March 29, 2024, and priority to the Chinese patent application with the invention name “A Reconfigurable Intelligent Metasurface”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of antenna technology, and more specifically, to a reconfigurable intelligent metasurface. Background Art

[0003] Metasurfaces and engineered materials with rationally designed subwavelength-scale building blocks enable us to control the behavior of physical fields in optics, microwaves, radio, acoustics, heat transfer, and other applications with flexibility and performance not achievable with natural materials. Planar, ultrathin metamaterials further expand these capabilities. Reconfigurable intelligent surfaces (RIS) with a transmissive-reflective architecture for multifunctional manipulation of electromagnetic waves across space have become a research hotspot for scholars both domestically and internationally, with promising applications in wireless communications, radar imaging, electromagnetic stealth, and smart skins.

[0004] Existing transflective metasurfaces typically exhibit multi-layered and complex structures. Furthermore, they typically employ polarization separation of two polarized waves to achieve transmission and reflection, which is less feasible. Furthermore, the beam scanning bandwidth is relatively narrow.

[0005] Therefore, how to design a reconfigurable intelligent metasurface that uses a single polarized wave to achieve transmission and reflection, has a simple structure, and has a large beam scanning bandwidth is a technical problem that needs to be solved urgently. Summary of the Invention

[0006] The present application provides a reconfigurable smart metasurface, which controls the reflection and transmission phase shift by controlling the on and off of semiconductor switches. In this way, the structure of the reconfigurable smart metasurface can be simplified.

[0007] In a first aspect, a reconfigurable smart metasurface is provided, characterized in that it includes: a first gridline layer, a first dielectric layer, and a first phase-shift layer arranged in a stacked manner; the first dielectric layer is used to support the first gridline layer and the first phase-shift layer, and the first dielectric layer is located between the first gridline layer and the first phase-shift layer; the first gridline layer is used to obtain a second electromagnetic wave having a first polarization direction; the first phase-shift layer has a first operating mode and a second operating mode, in the first operating mode, the first phase-shift layer performs polarization conversion and phase control on the second electromagnetic wave to obtain a third electromagnetic wave, and the third electromagnetic wave is emitted in a direction opposite to the first gridline layer; in the second operating mode, the first phase-shift layer performs phase control on the second electromagnetic wave, and the second electromagnetic wave is reflected toward the direction of the first gridline layer, and the phase control is used to achieve beam scanning and / or beam forming.

[0008] In this technical solution, the reconfigurable intelligent metasurface includes a three-layer structure, in which the phase-shift layer can realize the control of the transmission and reflection of electromagnetic waves, and can also realize phase regulation. It can be seen that through the design of the phase-shift layer, two functions (transmission and reflection and phase regulation) can be realized simultaneously on this structural layer, thereby directly simplifying the hierarchical structure. In addition, after the structure is simplified, it can be realized through micro-processing means, the process is mature, and it is easy to realize in high-frequency bands such as millimeter waves and terahertz, expanding the scope of application.

[0009] In combination with the first aspect, in some implementations of the first aspect, n phase shift units are provided on the first phase shift layer, each phase shift unit is provided with a semiconductor switch unit, and the semiconductor switch unit is used to control the first phase shift layer to operate in the first operating mode or the second operating mode, where n is a positive integer greater than or equal to 4.

[0010] In this technical solution, the switching of the working mode is achieved by setting a semiconductor switch unit on the phase shift layer. The semiconductor switch has a fast regulation function. It is used as the core dynamic functional material of the present invention to achieve high-speed phase shift reconfigurable characteristics.

[0011] In combination with the first aspect, in some implementations of the first aspect, the semiconductor switch unit includes a first switch and a second switch. In the first working mode, the on-off state of the semiconductor switch unit includes a first state and a second state. In the second working mode, the on-off state of the semiconductor switch unit includes a third state and a fourth state, wherein: the first state is that the first switch is disconnected and the second switch is turned on, the second state is that the first switch is turned on and the second switch is disconnected, the third state is that the first switch is disconnected and the second switch is disconnected, and the fourth state is that the first switch is turned on and the second switch is turned on.

[0012] In this technical solution, the on-off characteristics of two semiconductor switches are adjusted to change the equivalent circuit of the entire structure, thereby enabling the array to achieve phase control of transmission and reflection.

[0013] In combination with the first aspect, in some implementations of the first aspect, the phase difference between the phase shift in the first state and the phase shift in the second state is 180°, and the phase difference between the phase shift in the third state and the phase shift in the fourth state is 180°.

[0014] In this technical solution, by adjusting the on-off characteristics of the two semiconductor switches, not only transmission and reflection can be achieved, but also phase regulation can be achieved.

[0015] In combination with the first aspect, in some implementations of the first aspect, the second electromagnetic wave includes a millimeter wave or a terahertz wave.

[0016] In this technical solution, the reconfigurable smart surface can be applied to high frequency bands such as millimeter waves and terahertz.

[0017] In combination with the first aspect, in some implementations of the first aspect, the phase shift units provided on the first phase shift layer are arranged in an M×N array.

[0018] In combination with the first aspect, in certain implementations of the first aspect, a feed line is provided on both sides of each column of phase shift units in the M×N array along the longitudinal direction, the feed lines on both sides of each column of phase shift units are connected to the control unit from above, a feed line is provided below each column of phase shift units, and the feed lines provided at the lateral lower position of each column of phase shift units are connected to the control unit via a bus, wherein M and N are positive integers greater than or equal to 2.

[0019] In combination with the first aspect, in certain implementations of the first aspect, each of the phase shift units includes a square metal patch having a "J"-shaped groove, and the first switch and the second switch are respectively provided on the left and right sides of the "J"-shaped groove, and two feeders are respectively provided on the first switch and the second switch, connected to the feeders provided longitudinally on the two longitudinal sides.

[0020] In combination with the first aspect, in certain implementations of the first aspect, the reconfigurable smart metasurface further includes a second dielectric layer and a second grid line layer, the second dielectric layer being used to support the second grid line layer and the first phase shift layer, and the second dielectric layer being located between the second grid line layer and the first phase shift layer; the second grid line layer being used to obtain a fourth electromagnetic wave having a second polarization direction, the second polarization direction being orthogonal to the first polarization direction.

[0021] Based on the above solution, the second dielectric layer and the second gate line layer structure can improve the reflectivity or transmittance of electromagnetic waves.

[0022] In a second aspect, an antenna array is provided, comprising the reconfigurable intelligent metasurface described in any of the above aspects.

[0023] In a third aspect, a communication method is provided, which is applied to a reconfigurable smart metasurface. The reconfigurable smart metasurface includes a first grid line layer, a first dielectric layer, and a first phase shift layer arranged in a stacked manner. The first dielectric layer is used to support the first grid line layer and the first phase shift layer. The first dielectric layer is located between the first grid line layer and the first phase shift layer. The first grid line layer is used to obtain a second electromagnetic wave having a first polarization direction; in the first operating mode, the first phase shift layer performs polarization conversion and phase control on the second electromagnetic wave to obtain a third electromagnetic wave, and the third electromagnetic wave is emitted in a direction opposite to the first grid line layer; in the second operating mode, the first phase shift layer performs phase control on the second electromagnetic wave, and the second electromagnetic wave is reflected in the direction of the first grid line layer, and the phase control is used to achieve beam scanning and / or beam forming.

[0024] In this technical solution, the reconfigurable intelligent metasurface includes a three-layer structure, in which the phase-shift layer can realize the control of the transmission and reflection of electromagnetic waves, and can also realize phase regulation. It can be seen that through the design of the phase-shift layer, two functions (transmission and reflection and phase regulation) can be realized simultaneously on this structural layer, thereby directly simplifying the hierarchical structure. In addition, after the structure is simplified, it can be realized through micro-processing means, the process is mature, and it is easy to realize in high-frequency bands such as millimeter waves and terahertz, expanding the scope of application.

[0025] In combination with the third aspect, in certain implementations of the third aspect, the first phase-shift layer includes a semiconductor switch unit, the on / off state of the semiconductor switch unit is in a first state and a second state, and the first phase-shift layer operates in the first operating mode; the on / off state of the semiconductor switch unit is in a third state and a fourth state, and the first phase-shift layer operates in the second operating mode, wherein:

[0026] The first state is that the first switch is on and the second switch is off, the second state is that the first switch is off and the second switch is on, the third state is that the first switch is on and the second switch is on, and the fourth state is that the first switch is off and the second switch is off.

[0027] In a fourth aspect, a computer-readable storage medium is provided, which stores program code for execution by a device, wherein the program code includes code for executing the method provided in the third aspect.

[0028] In a fifth aspect, a computer program product comprising instructions is provided, which, when run on a computer, enables the computer to execute the method provided in the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 shows a schematic structural diagram of a reconfigurable smart surface provided in an embodiment of the present application.

[0030] FIG. 2 shows a schematic structural diagram of a first gate line layer 110 provided in an embodiment of the present application.

[0031] FIG3 shows a schematic structural diagram of a first phase-shift layer 130 provided in an embodiment of the present application.

[0032] FIG4 shows a schematic structural diagram of a phase shift unit provided in an embodiment of the present application.

[0033] FIG5 shows a schematic diagram of a phase shift unit pattern provided in an embodiment of the present application.

[0034] FIG6 shows a schematic diagram of the working principle of a reconfigurable intelligent metasurface provided in an embodiment of the present application.

[0035] FIG7 is a schematic diagram showing simulation results of current distribution in four states of a semiconductor switch provided in an embodiment of the present application.

[0036] FIG8 is a schematic diagram showing simulation results of reflection and transmission amplitudes and phase shift curves provided in an embodiment of the present application.

[0037] FIG9 is a schematic diagram showing the beam simulation scanning results of the reconfigurable smart surface provided in an embodiment of the present application at transmission and reflection angles of 10° to 60°.

[0038] FIG10 shows a schematic structural diagram of a reconfigurable smart surface provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solution in this application will be described below with reference to the accompanying drawings.

[0040] The embodiments described in this application are only some embodiments, not all embodiments. Based on the contents described in the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection required by the embodiments of this application.

[0041] The present application provides a reconfigurable intelligent metasurface that can be applied to antenna arrays, spatial light modulation of electromagnetic waves and electrically controlled two-dimensional imaging, as well as base station antennas, microwave antennas, satellite communications, millimeter-wave radars and other fields.

[0042] The antenna and / or antenna system of the embodiment of the present application can be applied to various communication systems, such as: global system for mobile communication (GSM) system, code division multiple access (CDMA) system, wideband code division multiple access (WCDMA) system, general packet radio service (GPRS), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, universal mobile telecommunication system (UMTS), world-wide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or new radio (NR), future communication system, intersatellite communication and satellite communication and other communication systems. The antenna and / or antenna system described in the embodiment of the present application can also be applied to other communication systems, which will not be described in detail here.

[0043] First, some terms in the embodiments of this application are introduced in detail.

[0044] 1. Metasurface

[0045] Metasurfaces are specialized composite materials formed by arranging artificial subwavelength structures according to a macroscopic sequence. These subwavelength structural units are equivalent to molecules or atoms in natural materials, but their equivalent dielectric constant and magnetic permeability can be arbitrary, and they lack the binding forces between molecules or atoms found in natural materials. This is unmatched by natural materials. Therefore, artificial microstructures possess more powerful electromagnetic wave control capabilities than natural molecules and atoms. To some extent, the novel properties of metasurfaces are independent of their material properties, but are determined by the subwavelength units and the macroscopic ordering. The concepts of digital coding and programmable metasurfaces provide a digital perspective for real-time control of electromagnetic wave propagation. Compared to metasurfaces with continuous parameters, digitally coded metasurfaces use binary codes to digitally describe physical parameters (such as amplitude, phase, and polarization). Thanks to the digitization of physical parameters, digitally coded metasurfaces enable simple design and binary coding operations for electromagnetic waves. For example, convolution operations have been applied to metasurfaces, allowing for arbitrary manipulation of scattered light beams in the upper space with virtually no distortion. Furthermore, the concept of information entropy has been applied to digitally coded metasurfaces, demonstrating the entropy of coding and scattering patterns. In the microwave field, programmable metasurfaces based on digitally coded metasurfaces were initially proposed to achieve real-time dynamic control of reflection patterns.

[0046] The manipulation of electromagnetic waves by metasurfaces mainly focuses on amplitude, phase, and polarization. By changing the mechanical design, changing the physical structure, changing the material properties of the medium, adding controllable circuit elements, and other methods, metasurfaces can have better control over electromagnetic waves. Depending on the scattering direction of the electromagnetic wave after passing through the metasurface, it can usually be divided into reflection type or transmission type. They only have the ability to manipulate electromagnetic waves in half space (reflection space or transmission space), but cannot process electromagnetic waves in the other half space. However, full-space metasurfaces can realize the manipulation of electromagnetic waves in both reflection and transmission states at the same time, and can also be called transmission-reflection integrated reconfigurable intelligent metasurfaces.

[0047] 2. Reconfigurable intelligent surface (RIS)

[0048] The use of reconfigurable intelligent metasurfaces with a transflective architecture to achieve multifunctional full-space control of electromagnetic waves has become a research hotspot for scholars both domestically and internationally. RIS (Reconfigurable Signal Processing) (RIS) offers significant application prospects in wireless communications, radar imaging, electromagnetic stealth, and smart skins. RIS is a two-dimensional metasurface composed of a large number of reconfigurable components, typically consisting of a large number of carefully designed electromagnetic units. By applying control signals to the adjustable elements within these units, RIS can dynamically control the electromagnetic properties of these units, thereby enabling programmable, intelligent control of electromagnetic waves in space, forming electromagnetic fields with controllable phase, amplitude, polarization, and frequency. RIS technology can flexibly manipulate the electromagnetic properties of a channel environment and offers the advantages of low cost, low energy consumption, programmability, and ease of deployment. It can address technical challenges and application needs in high-frequency communications and integrated communications.

[0049] Currently, there are numerous passive metasurfaces (non-reconfigurable) that can achieve full-space bidirectional beamforming applications. These technologies typically employ polarization diversity, structural adjustment, cascaded architectures, and frequency diversity to separate reflected and transmitted waves into two orthogonally polarized waves. Existing integrated transflective metasurfaces typically exhibit multilayered and complex structures, lack application in ultra-high frequency bands (e.g., the terahertz band), and exhibit narrow beam scanning bandwidths.

[0050] In view of this, the embodiment of the present application provides a reconfigurable intelligent metasurface, which controls reflection, transmission and phase shift by controlling the on and off of semiconductor switches on the basis of simplified structural design. It can be used in ultra-high frequency bands, has a wider range of application scenarios, and reduces processing complexity, which makes the device have great advantages in miniaturization, practicality and production.

[0051] The embodiment of the present application provides a reconfigurable intelligent metasurface, which belongs to RIS technology that can be applied to future communication systems and scenarios such as achieving synaesthesia integration. With the continued rapid growth of wireless network capacity demand, the use of higher frequency bands, larger bandwidths and densely distributed large-scale antenna arrays in future communication systems is an inevitable development trend. The communication frequency band will also gradually shift from the current microwave band to the higher frequency millimeter wave and terahertz bands. For synaesthesia integration, integrating communication and perception functions can not only reduce hardware costs and save spectrum resources, but also effectively avoid problems such as low work efficiency, low frequency band utilization, and decreased energy splitting performance caused by the separation of communication systems and perception systems. The embodiment provides a reconfigurable intelligent metasurface that can be applied to beam control in millimeter wave and terahertz bands, including beam shaping, beam scanning, beam deflection, etc. In addition to beam control, the reconfigurable array antenna can also be used in programmable holographic imaging systems, adaptive intelligent perception, new system wireless communication systems and other fields.

[0052] The following is a detailed description of the reconfigurable smart surface provided in the embodiments of the present application.

[0053] Referring to FIG. 1 , as an example, FIG. 1 shows a schematic structural diagram of a reconfigurable smart surface provided in an embodiment of the present application.

[0054] As shown in FIG. 1 , the reconfigurable smart surface includes a three-layer structure arranged in a stacked manner: a first gate line layer 110 , a first dielectric layer 120 , and a first phase-shift layer 130 .

[0055] The three-layer structure is described in detail below.

[0056] (1) First dielectric layer 120

[0057] The first dielectric layer 120 may also be referred to as a dielectric substrate. The first dielectric layer 120 is located between the first gate line layer 110 and the first phase-shift layer 130 and is used to support the first gate line layer 110 and the first phase-shift layer 130 .

[0058] The first dielectric layer 120 is used to support the first gateline layer 110 and the first phase-shift layer 130. It can be understood that the first dielectric layer 120 can serve as a processing carrier for the metal patterns of the first gateline layer 110 and the first phase-shift layer 130. For example, the first gateline layer 110 and the first phase-shift layer 130 can be provided on both surfaces of the first dielectric layer 120 in the form of metal coatings.

[0059] It can be understood that the first dielectric layer 120 is a support carrier for the first gate line layer 110 and the first phase shift layer 130 , and does not affect the function of the structure. Therefore, it can be replaced by any structure that can achieve the function of a support carrier, and the embodiment of the present application is not limited to this.

[0060] Exemplarily, the first dielectric layer 120 may be made of a semiconductor material, such as sapphire, high-resistance silicon, InP, GaAs, or silicon carbide, etc., which is not limited in the present embodiment.

[0061] It can be understood that the three-layer structure of the first gate line layer 110, the first dielectric layer 120 and the first phase shift layer 130 shown in Figure 1 is tightly stacked. The independent layering in Figure 1 is only for the convenience of illustrating the three-layer structure and does not limit the embodiment of the application.

[0062] (2) First gate line layer 110

[0063] The first gate line layer 110 is used to obtain a second electromagnetic wave having a first polarization direction. In other words, the electromagnetic wave having the first polarization direction can pass through the first gate line layer.

[0064] The second electromagnetic wave includes millimeter wave, terahertz wave or microwave.

[0065] Exemplarily, the millimeter wave frequency band ranges from 30 GHz to 300 GHz; the terahertz wave frequency band ranges from 0.1 THz to 10 THz; and the microwave frequency band ranges from 300 MHz to 300 GHz.

[0066] Specifically, when the incident first electromagnetic wave reaches the first gridline layer 110, the first electromagnetic wave with a first polarization direction can pass through the first gridline layer 110 to obtain the second electromagnetic wave. Conversely, the first electromagnetic wave with a polarization direction orthogonal to the first polarization direction will be reflected by the first gridline layer 110 and cannot pass through the first gridline layer 110.

[0067] It is understood that the first gridline layer 110 is used to transmit electromagnetic waves with a single polarization direction. For example, electromagnetic waves with a y-polarization direction can pass through the first gridline layer 110, while electromagnetic waves with a x-polarization direction will be reflected by the first gridline layer 110. For another example, electromagnetic waves with a x-polarization direction can pass through the first gridline layer 110, while electromagnetic waves with a y-polarization direction will be reflected by the first gridline layer 110.

[0068] Referring to FIG. 2 , as an example, FIG. 2 shows a schematic structural diagram of a first gate line layer 110 .

[0069] As shown in FIG. 2 , the first gate line layer 110 is a plurality of metal bars arranged in parallel on the surface of the first dielectric layer 120 .

[0070] The plurality of metal bars may be arranged at equal intervals or at non-equal intervals.

[0071] The gate line widths of the plurality of metal grids may be the same or different.

[0072] It should be understood that the plurality of metal bars arranged in parallel may be arranged in parallel in the horizontal direction or in the vertical direction.

[0073] It will be understood that the number of metal gate lines, the arrangement spacing of the metal gate lines, the width of the metal gate lines, and the arrangement direction of the metal gate lines shown in FIG. 2 are merely examples and do not limit the embodiments of the present application.

[0074] (3) First phase shift layer 130

[0075] The first phase-shift layer 130 has two operating modes, for example, a first operating mode and a second operating mode.

[0076] In the first operating mode, the first phase-shift layer 130 performs polarization conversion and phase control on the second electromagnetic wave to obtain a third electromagnetic wave, which is emitted in a direction opposite to the first gate line layer 110. In the second operating mode, the first phase-shift layer 130 performs phase control on the second electromagnetic wave, which is reflected in the direction of the first gate line layer 110. Phase control is used to achieve beam scanning and / or beam forming.

[0077] After the second electromagnetic wave with the first polarization direction enters the first phase-shift layer 130 , the polarization direction can be controlled (polarization conversion or non-polarization conversion) and the phase can be regulated in different working modes.

[0078] In the first operating mode, the first phase-shift layer 130 converts the polarization direction of the second electromagnetic wave into a third electromagnetic wave having the second polarization direction. The third electromagnetic wave is emitted in a direction opposite to the first gate line layer 110. In other words, the third electromagnetic wave can be emitted in the incident direction. For ease of description, this is hereinafter referred to as transmission of the incident wave.

[0079] In the second operating mode, the first phase-shift layer 130 does not convert the polarization direction of the second electromagnetic wave. The second electromagnetic wave with the first polarization direction can be emitted toward the first gate line layer 110. In other words, the second electromagnetic wave can be emitted in a direction opposite to the incident direction. For ease of description, this is hereinafter referred to as reflection of the incident wave.

[0080] It should be noted that part of the energy in the second electromagnetic wave can be emitted along the incident direction, that is, part of the energy can be transmitted, and part of the energy is emitted in the direction opposite to the incident direction, that is, only part of the second electromagnetic wave can pass through the first grid line layer and be reflected to the incident surface.

[0081] In a possible implementation, the first phase-shift layer 130 includes a switch unit, and the switch unit is used to implement the conversion between the first operating mode and the second operating mode.

[0082] Exemplarily, the switch unit may be a semiconductor switch unit, which includes two switches (a first switch and a second switch). For example, a high electron mobility transistor (HEMT) switch, a field effect transistor (FET), a phase change material, etc. This embodiment of the present application is not limited to this. The following description uses a semiconductor switch as an example.

[0083] In a possible implementation, in the first operating mode, the on-off state of the semiconductor switch unit includes a first state and a second state; in the second operating mode, the on-off state of the semiconductor switch unit includes a third state and a fourth state.

[0084] The first state is that the first switch is on and the second switch is off, the second state is that the first switch is off and the second switch is on, the third state is that the first switch is on and the second switch is on, and the fourth state is that the first switch is off and the second switch is off.

[0085] In one possible implementation, in order to implement beam scanning and beam forming with 1-bit train control coding, the phase difference between phase shifts in different states is 180°.

[0086] The phase difference between the phase shift in the first state and the phase shift in the second state is 180°, and the phase difference between the phase shift in the third state and the phase shift in the fourth state is 180°.

[0087] It is understood that the above 1 bit is only for exemplary purposes. For example, when the phase difference between the phase shifts in different states is 90°, beam scanning and beamforming with 2-bit column control coding can be implemented. This embodiment of the present application is not limited to this.

[0088] It should be understood that the conductor switch has a fast regulation function, and using it as the core dynamic functional material of the present application can achieve high-speed phase shift reconfigurable characteristics.

[0089] Next, the structure of the first phase-shift layer 130 will be described in detail.

[0090] The first phase-shift layer 130 includes n phase-shift units disposed on the surface of the first dielectric layer 120 , and each phase-shift unit is provided with a semiconductor switch unit.

[0091] Referring to FIG. 3 , as an example, FIG. 3 shows a schematic structural diagram of a first phase-shift layer 130 .

[0092] As shown in FIG. 3 , the first phase-shift layer 130 is disposed on the first dielectric layer 120 , and the n phase-shift units disposed on the first phase-shift layer 130 are arranged in an M×N array.

[0093] In which, a feed line 131 is respectively arranged along the longitudinal sides of each column of phase shift units in the M×N orthogonal array, and the feed lines on both sides of each column of phase shift units are connected to the control unit from the top through the metal patch 132. A feed line 133 is arranged below each column of phase shift units, and the feed line arranged below each column of phase shift units is connected to the bus 134, and the bus is connected to the control unit through the metal patch 135. In which, M and N are positive integers greater than or equal to 2.

[0094] The feed lines 131 on both sides of each column of phase shift units are connected to the control unit from above, and the feed lines on both sides of each column of phase shift units can be independently controlled.

[0095] The control unit is not shown in the figure. The control unit is, for example, a field-programmable gate array (FPGA) control board.

[0096] The feeder line may be a metal feeder line.

[0097] For example, the metal feed line and the metal patch may be made of Au, Ag, Cu, or Al, which is not limited in this embodiment of the present application.

[0098] Next, the structure of the phase shift unit will be described in detail.

[0099] Referring to FIG. 4 , as an example, FIG. 4 shows a schematic structural diagram of a phase shift unit.

[0100] Each phase shift unit includes a square metal patch with a "J"-shaped groove. A first switch 136 and a second switch 137 are respectively provided on the left and right sides of the "J"-shaped groove. Two feeders 138 are respectively provided on the first switch 136 and the second switch 137 and connected to the feeders 131 provided along the longitudinal sides.

[0101] The first switch 136 and the second switch 137 constitute a semiconductor switch unit.

[0102] As an example, the on-off control of the semiconductor switch can be achieved by applying different voltages to the feeder by the control unit. The embodiment of the present application does not limit the control method of the semiconductor switch.

[0103] It is understood that the present application operates through electrical control to achieve dynamic broadband phase regulation, without the need for external light excitation, temperature excitation, or other more complex excitation methods, giving the device significant advantages in miniaturization, practicality, and production volume.

[0104] The doped heterogeneous material of the semiconductor switch may be AlGaN / GaN, InGaN / GaN, or AlGaAs / GaAs, which is not limited in the present embodiment.

[0105] It should be noted that, in addition to the "X"-shaped pattern, other patterns are also applicable to the square metal patch on each phase shift unit.

[0106] Referring to Figure 5, as an example, Figure 5 shows a schematic diagram of a phase shift unit pattern. Patterns (a) and (b) shown in Figure 5 can both be set on the phase shift unit. The present application does not limit the specific pattern on the phase shift unit.

[0107] Based on the above technical solution, the reconfigurable intelligent metasurface proposed in this application can achieve reflection, transmission, and phase control of electromagnetic waves through a three-layer structure. This structure is simple and can be realized through microfabrication methods. The process is mature and easy to manufacture in high-frequency bands such as millimeter waves and terahertz.

[0108] The above is a description of the structure of the reconfigurable intelligent metasurface proposed in the embodiments of the present application.

[0109] The working principle of the reconfigurable intelligent metasurface proposed in the embodiments of the present application is described in detail below.

[0110] Refer to Figure 6, as an example, refer to Figure 6, which shows a schematic diagram of the working principle of a reconfigurable smart metasurface.

[0111] The first gate line layer 110 in FIG. 6 can obtain electromagnetic waves in the y-polarization direction, that is, the electromagnetic waves in the y-polarization direction can pass through the first gate line layer 110 .

[0112] The polarization direction of the incident wave in Fig. 6 is y-polarized as an example. The electromagnetic wave in the y-polarized direction is an example of the second electromagnetic wave and is hereinafter referred to as y-polarized wave.

[0113] The y-polarized wave reaches the first gate line layer 110, passes through the first gate line layer 110 and the first dielectric layer 120, and reaches the first phase shift layer 130. The first phase shift layer can control the operating mode through a semiconductor switch (for example, the first switch and the second switch shown in FIG. 4 ), which can specifically include the following four operating states:

[0114] First state: when the first switch is off and the second switch is on, the first phase shift layer operates in the first operating mode, and the first phase shift layer performs polarization conversion on the y-polarized wave to obtain an x-polarized wave, which can be transmitted along the incident direction.

[0115] Second state: when the first switch is on and the second switch is off, the first phase shift layer operates in the first operating mode, and the first phase shift layer performs polarization conversion on the y-polarized wave to obtain an x-polarized wave, which can be transmitted along the incident direction.

[0116] Third state: when the first switch is turned off and the second switch is turned off, the first phase-shift layer operates in the second operating mode. The first phase-shift layer does not perform polarization conversion on the y-polarized wave, and it remains a y-polarized wave. Part of the y-polarized wave can pass through the first gate line layer 110 and be reflected in a direction opposite to the incident direction.

[0117] Fourth state: when the second switch is turned on, the first phase-shift layer operates in the second operating mode. The first phase-shift layer does not perform polarization conversion on the y-polarized wave, and it remains a y-polarized wave. Part of the y-polarized wave can pass through the first gate line layer 110 and be reflected in a direction opposite to the incident direction.

[0118] The working principle of phase control performed by the first phase shift layer is described below with reference to FIG7 , FIG8 and FIG9 .

[0119] Referring to FIG. 7 , as an example, FIG. 7 shows a schematic diagram of current distribution simulation results in four states of the semiconductor switch.

[0120] Figure 7 (a) shows the current distribution diagram in the first state (state 1), Figure 7 (b) shows the current distribution diagram in the third state (resonant state 1), Figure 7 (c) shows the current distribution diagram in the second state (state 2), and Figure 7 (d) shows the current distribution diagram in the fourth state (resonant state 2).

[0121] As can be seen from Figure 7 (a) and (c), in the first and second states, the currents in the left and right arms of the "X"-shaped slot of the phase shift unit are asymmetric, allowing polarization conversion, resulting in the transmission of electromagnetic waves. At this time, since the current directions of the left and right arms of the "X"-shaped slot of the phase shift unit in the two states differ by 90°, current reversal occurs. According to the geometric phase principle, the first and second states have a 180° phase difference (1-bit phase difference).

[0122] As can be seen from Figure 7 (b) and (d), in the third and fourth states, the currents in the left and right arms of the "X"-shaped slot of the phase shift unit are symmetrical, and the polarization conversion function is not realized, resulting in electromagnetic wave reflection. At this time, since the currents in the left and right arms of the "X"-shaped slot of the phase shift unit in the two states form a symmetrical structure, a resonant state is formed. The resonant frequency shift in the first and second states is 180° out of phase (1-bit phase difference).

[0123] Referring to FIG8 , as an example, FIG8 shows a schematic diagram of simulation results of amplitude and phase shift curves of reflection and transmission.

[0124] The simulation results shown in Figure 8 use a HEMT as an example semiconductor switch. Changing the voltage difference between the positive and negative lines connected to the transistor electrodes in the structure causes the transistor to switch between off and on states. The simulation results demonstrate that the applied voltage modulates the semiconductor switch's off and on states, enabling phase control of the reflected and transmitted waves.

[0125] FIG8(a) shows the transmission amplitude and phase shift characteristics, and FIG8(b) shows the reflection amplitude and phase shift characteristics.

[0126] As shown in (a) of Figure 8, the horizontal axis is frequency (in THz), and the vertical axis is phase (in angle) and transmission amplitude. When the semiconductor switch of the phase shift unit is in the first state or the second state, the available variable frequency band with a transmission amplitude of more than 0.3 and a phase difference of 180 degrees is around 0.18 THz, which can reach 40 GHz, and the adjustable range is relatively large.

[0127] As shown in (b) of Figure 8, the horizontal axis is frequency (in THz), the vertical axis is phase (in angle) and reflection amplitude. When the semiconductor switch is in the third state or the fourth state, the phase shift unit can achieve a phase shift of about 180 degrees at around 0.16 THz, within a frequency band of about 21 GHz, with an amplitude between 0.4 and 0.5.

[0128] The above results show that under any working state, the working bandwidth range of the phase shift unit is significantly increased and the beam scanning bandwidth is increased.

[0129] As an example, Figure 9 shows a schematic diagram of the simulated scanning results of a reconfigurable smart surface provided by an embodiment of the present application at transmission and reflection angles of 10° to 60°. In this figure, the horizontal axis represents the scanning angle, and the vertical axis represents the far-field directivity, which describes the distribution of the antenna's radiated energy in different directions. This figure provides an understanding of the antenna's radiation intensity and range in different directions.

[0130] FIG9( a ) shows the scanning result of the y-polarized electromagnetic wave reflected beam. From the simulation results, it can be seen that the y-polarized electromagnetic wave reflected beam scanning can be achieved for the y-polarized electromagnetic wave, and the scanning capability is ±60°.

[0131] FIG9( b ) shows the scanning result of the x-polarized electromagnetic wave transmission beam. From the simulation results, it can be seen that the x-polarized electromagnetic wave transmission beam scanning can be achieved for the x-polarized electromagnetic wave, and the scanning capability is ±60°.

[0132] Based on the above scheme, this application adopts a two-dimensional planar artificial microstructure to change the equivalent circuit of the entire structure by adjusting the on-off characteristics of two semiconductor switches, so that the array can achieve phase control of transmission and reflection. In addition, the structure is simple and can be achieved through micro-machining means. The process is mature and easy to implement in high-frequency bands such as millimeter waves and terahertz.

[0133] In one possible implementation, the reconfigurable smart metasurface further includes a second dielectric layer and a second gate line layer.

[0134] The second dielectric layer is used to support the second gate line layer and the first phase-shift layer, and the second dielectric layer is located between the second gate line layer and the first phase-shift layer.

[0135] The second grid line layer is used to obtain a fourth electromagnetic wave with a second polarization direction, and the second polarization direction is orthogonal to the first polarization direction.

[0136] Referring to FIG. 10 , as an example, FIG. 10 shows a schematic structural diagram of a reconfigurable smart surface provided in an embodiment of the present application.

[0137] As shown in FIG. 10 , the reconfigurable smart surface includes a five-layer structure arranged in a stacked manner: a first gate line layer 110 , a first dielectric layer 120 , a first phase-shift layer 130 , a second dielectric layer 140 and a second gate line layer 150 .

[0138] The first gate line layer 110 , the first dielectric layer 120 , and the first phase-shift layer 130 may be described with reference to FIG. 1 , and will not be described in detail herein.

[0139] The second dielectric layer 140 has the same function and material as the first dielectric layer 120 , and reference may be made to the description in FIG1 , which will not be repeated here.

[0140] The second gridline layer 150 is used to obtain a fourth electromagnetic wave having a second polarization direction, that is, an electromagnetic wave having a polarization direction orthogonal to the first polarization direction can pass through the second gridline layer. In other words, if the electromagnetic wave emitted from the first phase-shift layer is in the first polarization direction, it will be reflected back to the first gridline layer. If the electromagnetic wave emitted from the first phase-shift layer is in the second polarization direction, it can pass through the second gridline layer.

[0141] Exemplarily, the first polarization direction is the y-polarization direction, and the second polarization direction is the x-polarization direction. When the first electromagnetic wave (y-polarization direction) passes through the first grid line layer, a second electromagnetic wave is obtained. The second electromagnetic wave reaches the first phase-shift layer. If polarization conversion occurs, a third electromagnetic wave (x-polarization direction) is obtained. The third electromagnetic wave is emitted in the incident direction, passes through the second dielectric layer, and reaches the second grid line layer. The third electromagnetic wave in the x-polarization direction can pass through the second grid line layer to obtain a fourth electromagnetic wave. If the second electromagnetic wave does not undergo polarization conversion in the first phase-shift layer, part of the second electromagnetic wave is reflected back through the first grid line layer in a direction opposite to the incident direction, and another part of the second electromagnetic wave can be emitted in the incident direction, pass through the second dielectric layer, and reach the second grid line layer. The second electromagnetic wave in the y-polarization direction will be reflected back to the first phase-shift layer by the second grid line layer, and can then pass through the first grid line layer and be reflected back to the incident surface.

[0142] Based on the above solution, the second dielectric layer and the second gate line layer structure can improve the reflectivity or transmittance of electromagnetic waves.

[0143] The present application also provides an antenna array, comprising the above-mentioned reconfigurable smart metasurface.

[0144] This application also provides a communication method, which is applied to the above-mentioned reconfigurable intelligent metasurface. The specific structure can be referred to the above description and will not be repeated here.

[0145] In one possible implementation, in the first operating mode, the first phase-shift layer performs polarization conversion and phase control on the second electromagnetic wave to obtain a third electromagnetic wave, and the third electromagnetic wave is emitted in a direction opposite to the first gridline layer; in the second operating mode, the first phase-shift layer performs phase control on the second electromagnetic wave, and the second electromagnetic wave is reflected toward the first gridline layer.

[0146] In one possible implementation, the first phase-shift layer includes a semiconductor switch unit, the on-off state of the semiconductor switch unit is in a first state and a second state, and the first phase-shift layer operates in a first operating mode; the on-off state of the semiconductor switch unit is in a third state and a fourth state, and the first phase-shift layer operates in a second operating mode. The first state, the second state, the third state, and the fourth state can be referred to in the previous description and will not be repeated here.

[0147] Based on the above scheme, this application provides an artificial microstructure array with both reflection and transmission capabilities within a specific frequency range. By applying an external voltage to control the on and off of semiconductor switches, the original phase-shifting structure is altered, ultimately achieving phase control of reflection and transmission. Furthermore, this structure is simple and can be fabricated using mature microfabrication techniques, making it readily applicable to high-frequency bands such as millimeter waves and terahertz frequencies.

[0148] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0149] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0150] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0151] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0152] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0153] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0154] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A reconfigurable intelligent metasurface, characterized in that: include: A first gate line layer, a first dielectric layer, and a first phase shift layer are stacked; The first dielectric layer is used to support the first gate line layer and the first phase-shift layer, and the first dielectric layer is located between the first gate line layer and the first phase-shift layer; The first grid line layer is used to obtain a second electromagnetic wave with a first polarization direction; The first phase-shift layer has a first working mode and a second working mode. In the first working mode, the first phase-shift layer performs polarization conversion and phase control on the second electromagnetic wave to obtain a third electromagnetic wave, and the third electromagnetic wave is emitted in a direction opposite to the first gate line layer. In the second working mode, the first phase-shift layer performs phase control on the second electromagnetic wave, and the second electromagnetic wave is reflected toward the first grid line layer. The phase control is used to achieve beam scanning and / or beam forming.

2. The reconfigurable smart metasurface according to claim 1, characterized in that: The first phase-shift layer is provided with n phase-shift units, each of which is provided with a semiconductor switch unit, and the semiconductor switch unit is used to control the first phase-shift layer to operate in the first operating mode or the second operating mode, wherein n is a positive integer greater than or equal to 4.

3. The reconfigurable smart metasurface according to claim 2, characterized in that: The semiconductor switch unit includes a first switch and a second switch. In the first operating mode, the on-off state of the semiconductor switch unit includes a first state and a second state. In the second operating mode, the on-off state of the semiconductor switch unit includes a third state and a fourth state, wherein: The first state is that the first switch is off and the second switch is on, the second state is that the first switch is on and the second switch is off, the third state is that the first switch is off and the second switch is off, and the fourth state is that the first switch is on and the second switch is on.

4. The reconfigurable intelligent metasurface according to claim 3, characterized in that: A phase difference between the phase shift in the first state and the phase shift in the second state is 180°, and a phase difference between the phase shift in the third state and the phase shift in the fourth state is 180°.

5. The reconfigurable smart metasurface according to any one of claims 1 to 4, characterized in that: The second electromagnetic wave includes a millimeter wave or a terahertz wave.

6. The reconfigurable smart metasurface according to any one of claims 1 to 5, characterized in that: The phase shift units provided on the first phase shift layer are arranged in an M×N array.

7. The reconfigurable smart metasurface according to claim 6, characterized in that: A feed line is provided on both longitudinal sides of each column of phase shift units in the M×N array, the feed lines on both sides of each column of phase shift units are connected to the control unit from above, a feed line is provided below each column of phase shift units, and the feed lines provided laterally below each column of phase shift units are connected to the control unit via a bus, wherein M and N are positive integers greater than or equal to 2.

8. The reconfigurable intelligent metasurface according to claim 6 or 7, characterized in that: Each phase shift unit includes a square metal patch with a "J"-shaped slot. A first switch and a second switch are respectively provided on the left and right sides of the "J"-shaped slot. Two feeders are respectively provided on the first switch and the second switch to connect to the feeders provided along the longitudinal sides.

9. The reconfigurable smart metasurface according to any one of claims 1 to 8, characterized in that: The reconfigurable intelligent metasurface further includes a second dielectric layer and a second gate line layer. The second dielectric layer is used to support the second gate line layer and the first phase-shift layer, and the second dielectric layer is located between the second gate line layer and the first phase-shift layer; The second grid line layer is used to obtain a fourth electromagnetic wave having a second polarization direction, where the second polarization direction is orthogonal to the first polarization direction.

10. An antenna array, characterized in that: A reconfigurable smart metasurface comprising any one of claims 1-9.

11. A communication method, characterized in that: Applied to a reconfigurable smart metasurface, the reconfigurable smart metasurface includes a first gridline layer, a first dielectric layer, and a first phase-shift layer arranged in a stacked manner, the first dielectric layer being used to support the first gridline layer and the first phase-shift layer, the first dielectric layer being located between the first gridline layer and the first phase-shift layer, and the first gridline layer being used to obtain a second electromagnetic wave having a first polarization direction; In a first operating mode, the first phase-shift layer performs polarization conversion and phase control on the second electromagnetic wave to obtain a third electromagnetic wave, and the third electromagnetic wave is emitted in a direction opposite to the first grid line layer. In a second operating mode, the first phase-shift layer performs phase control on the second electromagnetic wave, and the second electromagnetic wave is reflected in the direction of the first grid line layer. The phase control is used to achieve beam scanning and / or beam forming.

12. The method according to claim 11, characterized in that The first phase-shift layer includes a semiconductor switch unit, the on-off state of the semiconductor switch unit is in a first state and a second state, and the first phase-shift layer operates in the first operating mode; the on-off state of the semiconductor switch unit is in a third state and a fourth state, and the first phase-shift layer operates in the second operating mode, wherein: The first state is that the first switch is on and the second switch is off, the second state is that the first switch is off and the second switch is on, the third state is that the first switch is on and the second switch is on, and the fourth state is that the first switch is off and the second switch is off.

13. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program or instruction. When the computer program or instruction is executed on a communication device, the communication device is caused to perform the method according to any one of claims 11 to 12.

14. A computer program product, characterized in that The computer program product comprises a computer program or instructions for performing the method according to any one of claims 11 to 12.

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