Multi-feed-source dynamic multi-beam scanning method and device for transmission metasurface

Abstract

The invention discloses a multi-feed-source dynamic multi-beam scanning method and device for a transmission metasurface, and belongs to the technical field of wireless communication. The system comprises a transmission metasurface module used for transmitting electromagnetic waves and realizing beam forming, an antenna excitation module used for radiating the electromagnetic waves, and a feed source digital regulation and control module used for dynamic multi-beam generation regulation and control. The antenna excitation module is perpendicular to the array plane of the transmission metasurface module, and the antenna excitation module and the feed source digital regulation and control block are sequentially and electrically connected according to mode setting. The feed source digital regulation and control module is combined with the antenna excitation module to form three modes which are respectively a single feed source mode, a multi-feed source mode and a phased array mode, dynamic multi-beam modulation is performed through the system in radiation of different modes, beam digital regulation and control are realized in combination with the transmission metasurface module, and dynamic shaping of beams generated by the system is determined at the same time. According to the invention, a low-cost alternative scheme of a super-large-scale MIMO technology is realized, and flexible and controllable dynamic multi-beam forming is realized.

Description

Technical Field

[0001] The present invention belongs to the field of wireless communication technology, and specifically refers to a multi-feed dynamic multi-beam scanning method and device for a transmission metasurface. Background Art

[0002] In order to meet the needs of future 6G networks for large-scale data transmission and connected devices, and to provide faster, more stable and more extensive wireless communication services, Massive MIMO technology is a key technology that can effectively improve the capacity, coverage and signal quality of 5G networks. However, Massive MIMO technology requires the use of a large number of antennas and transceiver hardware, and has high requirements and costs for equipment, which limits the popularity and application scope of Massive MIMO technology. Moreover, although Massive MIMO technology can improve the utilization efficiency of spectrum resources by using multiple antennas to transmit multiple signals, the signal transmission of multiple close-range antennas under near-field conditions may be affected by multipath effects, damping loss, etc., resulting in the inability to fully improve the utilization efficiency of spectrum resources.

[0003] Metasurface is a new type of artificial electromagnetic structure. By designing the geometry, material and arrangement of its surface units, the transmission, reflection, refraction and other characteristics of electromagnetic waves can be flexibly manipulated over a wide range. This technology is different from traditional optical and electromagnetic methods. It can achieve efficient control of electromagnetic waves on a subwavelength scale, thereby realizing functions such as dynamic beamforming, wavefront reconstruction, and multi-beam generation.

[0004] Compared with very large-scale MIMO, transmissive metasurfaces have higher space utilization efficiency and can achieve functions similar to very large-scale MIMO arrays in a smaller physical space, reducing the number and layout requirements of physical antennas, thus having obvious economic advantages. By dynamically adjusting the electromagnetic response of metasurface units, transmissive metasurfaces can change the propagation path and characteristics of electromagnetic waves in real time, providing higher flexibility and adjustability than very large-scale MIMO arrays. Therefore, it is necessary to propose a system solution that combines a small number of feed sources with transmissive metasurfaces to achieve multi-channel signal transmission with higher flexibility and adjustability, improve the utilization efficiency of spectrum resources, and solve the problem of a huge number of antennas and high costs in traditional very large-scale MIMO systems. Summary of the invention

[0005] In order to solve the problems existing in Massive MIMO technology, the present invention provides a multi-feed dynamic multi-beam scanning method and device for a transmissive metasurface, which uses the generalized Snell's law to design a metasurface array with a given precoding, constructs a near-field channel between the feed antenna and the transmissive metasurface, and realizes low-cost, flexible and adjustable dynamic multi-beam control by selecting or regulating the position and excitation of a small number of feeds.

[0006] A multi-feed dynamic multi-beam scanning method for a transmissive metasurface performs dynamic multi-beam modulation according to different radiation modes, specifically:

[0007] First, the high-transmittance phase modulation unit at each position of the transmission metasurface module determines the transmission compensation phase and amplitude of the unit at that position through the generalized Snell's law, so that the electromagnetic wave signal propagating on one side can be intelligently controlled;

[0008] Then, dynamic multi-beam modulation is performed in different radiation modes of the feed excitation module:

[0009] (1) The orientation of a single microstrip patch antenna in single feed mode is always perpendicular to the transmissive metasurface array, and dynamic beam deflection of the target beam is achieved by moving the position of the microstrip patch antenna relative to the transmissive metasurface module;

[0010] The position movement of the microstrip patch antenna includes the front, back, left, right, top and bottom positions relative to the transmission metasurface array, and the movement distance in each position affects the system beamforming;

[0011] (2) The orientations of several microstrip patch antennas in the multi-feed mode are always perpendicular to the transmission metasurface array, and the amplitude and phase excitation coefficients of the antennas remain consistent. Multi-beam generation is achieved by moving the positions of several microstrip patch antennas relative to the transmission metasurface module and the positional relationship between the combined microstrip patch antennas.

[0012] The position movement of the microstrip patch antenna includes the front, back, left, right, top and bottom positions relative to the transmission metasurface array. The movement distance in each position affects the multi-beam forming of the system. The position relationship between the microstrip patch antennas includes the relationship between the number and the position, and determines the number and shape of the beams generated by the multi-beam system.

[0013] (3) The orientation of several microstrip patch antennas in the phased array feed mode is always perpendicular to the transmission metasurface array surface. The phased array is an array structure composed of several microstrip patch antennas arranged at equal intervals in a plane. The operating frequency is 10 GHz, and the array element spacing is 15 mm half wavelength. Single beam generation is achieved by moving the position of the antenna excitation module relative to the transmission metasurface module in the phased array mode and changing the amplitude and phase excitation coefficients of several microstrip patch antennas.

[0014] The position movement of the antenna excitation module includes the front, back, left, right, top and bottom positions relative to the transmissive metasurface array, and the movement distance in each position affects the system beamforming; a number of microstrip patch antennas are arranged at equal intervals of half a wavelength to form a phased array feed mode, and the amplitude and phase excitation coefficients of the microstrip patch antennas are encoded through a phased array based on particle swarm optimization combined with a transmissive metasurface system matching scheme, and the digital beam control is realized in combination with the transmissive metasurface module, while the dynamic shaping of the beam generated by the system is determined.

[0015] To achieve the above-mentioned dynamic multi-beam modulation, a multi-feed dynamic multi-beam scanning device facing a transmissive metasurface includes a transmissive metasurface module for transmitting electromagnetic waves and realizing beamforming, an antenna excitation module for radiating electromagnetic waves, and a feed digital control module for dynamic multi-beam generation and control; the antenna excitation module is perpendicular to the array surface of the transmissive metasurface module, and the antenna excitation module and the feed digital control block are electrically connected in sequence according to a pattern setting.

[0016] The transmission metasurface module is a rectangular array structure composed of a number of high-transmittance phase modulation units arranged periodically and at equal intervals in a plane;

[0017] Optionally, the high-transmittance phase modulation unit is a frequency-selective structure composed of three intermediate dielectric layers and four metal layers, the four metal layers are separated by the three intermediate dielectric layers, the metal layers are etched on the dielectric layers, and the three dielectric layers are interconnected by bonding;

[0018] The metal layer includes a square ring at the edge and a quasi-snow spot shape at the center, the outer periphery of the square ring is a square, the middle is hollowed out, and the quasi-snow spot shape is located at the center of the hollowed-out part;

[0019] The high transmittance phase modulation unit realizes 360° continuous transmission phase regulation by changing the length of the quasi-snow spot shape, and the insertion loss of the high transmittance phase modulation unit is less than 2.5dB;

[0020] The transmission metasurface module realizes the array arrangement design of multiple high-transmittance phase modulation units based on the generalized Snell's law. The generalized Snell's law is applied to the metasurface to achieve phase regulation by introducing phase mutation. The generalized Snell's law of refraction formula is:

[0021]

[0022] In the formula, θ t and θ i Represent the refraction angle and incident angle of the plane wave, n t With n i are the refractive indices of the media in which the refracted wave and the incident wave are located, k 0 =2π / λ 0 is the free space wave number at the design frequency, λ0 is the free space wavelength corresponding to the electromagnetic wave frequency, and dx represents the distance between the incident points of the two paths on the interface.

[0023] Optionally, the high transmittance phase modulation unit arrangement design follows the generalized Snell's law, and the expected compensation phase distribution of the array element at the array element position (x, y) in the array deflected on the E plane and the H plane is:

[0024]

[0025] In the formula, θ 0 The beam deflection angle is the angle along the z axis, and the position is (x 0 ,y 0 ), the distance between the feed source and the metasurface is F.

[0026] The antenna excitation module is located on one side of the transmission metasurface module, and is composed of a number of microstrip patch antennas for emitting electromagnetic waves. The microstrip patch antenna units are arranged periodically and evenly spaced in a plane, and radiate different numbers and types of electromagnetic waves through different modes of the feed source digital control module.

[0027] Optionally, the microstrip patch antenna is designed based on the mutual coupling of a microstrip transmission line and a metal patch, and its structure includes a dielectric substrate, a metal patch attached to the top side of the dielectric substrate, and a metal patch on the bottom side of the substrate corresponding to the patch, and a feeding coaxial line runs through the microstrip patch antenna, connecting the metal patches on the top side and the bottom side, and is used to provide feeding of electrical signals;

[0028] The feed digital control module is composed of a number of digital control feed excitation circuits, which are combined with the antenna excitation module to form three modes, namely single feed mode, multi-feed mode and phased array mode.

[0029] Optionally, the single feed mode is composed of only a single microstrip patch antenna as an antenna excitation module, and the placement position of the single microstrip patch antenna is determined according to the focal design position of the transmission metasurface module and the target beam deflection angle;

[0030] Optionally, the multi-feed mode is composed of a plurality of microstrip patch antennas as antenna excitation modules and a plurality of power division circuits as feed digital control modules. In this mode, a plurality of microstrip patch antennas are randomly arranged, and the number of microstrip patch antennas is adjusted according to the target beam; the output end of the power division circuit is respectively connected to a plurality of microstrip patch antennas, and the placement position of the microstrip patch antenna is determined according to the focal design position of the transmission metasurface module, the number of target generated beams, and the respective deflection angles of the target beams;

[0031] Optionally, the phased array mode is composed of a number of microstrip patch antennas as antenna excitation modules and a number of power division circuits, amplification circuits, phase shifting circuits, and attenuation circuits as feed digital control modules. Each microstrip patch antenna unit is on one side of the transmission metasurface module and in the same direction as the metasurface. The microstrip patch antennas are arranged at equal intervals in the plane to form an array structure. The array element spacing meets the half-wavelength requirement, and the array combination shape is adjusted according to the target beam scanning range; in the feed excitation module, the signal excitation is input from the power division circuit, and the output end of the power division circuit is respectively connected to the input end of the phase shifting circuit, and the output end of each phase shifting circuit is correspondingly connected to the input end of each amplification circuit, and the output end of each amplification circuit is correspondingly connected to the input end of each attenuation circuit, and the output end of each attenuation circuit is correspondingly connected to each microstrip patch antenna unit of the antenna array. After digital control, the signal is output from the microstrip patch antenna to realize beam forming.

[0032] The present invention has the following beneficial effects:

[0033] (1) The present invention realizes a low-cost alternative to ultra-large-scale MIMO technology by combining a feed excitation module with a transmission metasurface module, and realizes flexible and controllable dynamic multi-beamforming by intelligently controlling the metasurface transmission beam.

[0034] (2) The present invention simplifies the target beam modulation method and realizes large-angle beam scanning and multi-beam modulation generation by moving the feed position, increasing or decreasing the number of feeds, and digitally controlling the feed array excitation, while greatly improving the beam gain.

[0035] (3) The system of the present invention has the advantages of low profile, low cost, high precision and rapid adjustment, and can be widely used in the field of 6G communication services for multiple users. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of a multi-feed dynamic multi-beam scanning device for a transmission metasurface of the present invention;

[0037] Figure 2 It is a schematic diagram of another viewing angle of the structure of a multi-feed dynamic multi-beam scanning device facing a transmission metasurface of the present invention;

[0038] Figure 3 is a schematic structural diagram of a transmission metasurface module of the present invention;

[0039] Figure 4 is a schematic diagram of a high transmittance phase modulation unit of the present invention;

[0040] Figure 5 The test results of the high transmittance phase modulation unit structure and phase relationship of the present invention;

[0041] Figure 6It is a schematic diagram of the structure of the microstrip patch antenna of the present invention;

[0042] Figure 7 It is a structural block diagram of three modes of the antenna excitation module of the present invention;

[0043] Figure 8 It is a structural block diagram of three modes of the feed digital control module of the present invention.

[0044] In the figure:

[0045] 1-transmission metasurface module, 2-antenna excitation module, 3-feed source digital control module, 4-high transmittance phase modulation unit, 5-quasi-snow spot metal layer, 6-square ring metal layer, 7-dielectric layer, 8-microstrip patch antenna, 9-dielectric substrate, 10-rectangular metal patch, 11-square metal patch, 12-feed coaxial line, 13-signal transmission circuit, 14-power division circuit, 15-phase shift circuit, 16-amplification circuit, 17-attenuation circuit. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0047] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] The embodiment of the present invention provides a multi-feed dynamic multi-beam scanning device for a transmission metasurface, such as Figure 1 and Figure 2 As shown, it includes a transmission metasurface module 1 for transmitting electromagnetic waves and realizing beamforming, an antenna excitation module 2 for radiating electromagnetic waves, and a feed source digital control module 3 for dynamic multi-beam generation control.

[0049] like Figure 2 As shown, the transmission metasurface module 1 can be oriented arbitrarily, and the antenna excitation module 2 needs to be oriented always perpendicular to the array surface of the transmission metasurface module 1 to ensure that the equally spaced high-transmittance phase-modulation units arranged according to the generalized Snell's law can provide accurate phase compensation. The antenna excitation module 2 and the feed digital control module 3 are electrically connected in sequence according to the mode setting.

[0050] like Figure 3As shown, the transmission metasurface module 1 is a rectangular array structure composed of a number of high-transmittance phase-modulating units 4 arranged periodically and equidistantly in a plane according to the generalized Snell's law. Each high-transmittance phase-modulating unit 4 includes a quasi-snow-spotted metal layer 5, a square ring metal layer 6 and a dielectric layer 7 stacked in sequence. The quasi-snow-spotted metal layer 5 and the square ring metal layer 6 together form a metal layer, which is made of metal material. There are 4 stacked layers, and there are 3 stacked layers of the dielectric layer 7. The refractive phase of each high-transmittance phase-modulating unit 4 can be controlled by controlling the length of the structural parameter L of each quasi-snow-spotted metal layer 5, thereby controlling the transmission beam of the transmission metasurface module 1. The design of the four layers of quasi-snow-spotted metal layers 5 of each high-transmittance phase-modulating unit 4 remains consistent.

[0051] In a specific implementation, the high-transmittance phase-modulating units 4 are periodically arranged to form a transmission metasurface module 1, and the square ring metal layers 6 of the high-transmittance phase-modulating units 4 are also connected due to the periodic arrangement. At the same time, the metal layer is etched on the dielectric layer 7, and the three dielectric layers 7 need to be connected to each other, such as Figure 4 As shown, an adhesive layer 8 needs to be added between every two dielectric layers 7. There is no specific material selected for the adhesive layer, but the electromagnetic propagation characteristics of the material will affect the selection of the length of the structural parameter L of the quasi-snow spot metal layer 5.

[0052] The width of the square ring is m=0.2mm, and the boundary distance is 0mm; the quasi-snow spot shape is formed by a rectangular metal sheet with a length of L and a width of w rotating and etching at the center of the square ring; the L value of the quasi-snow spot shape is 1mm~9mm, and w=3mm; the dielectric layer adopts F4B polytetrafluoroethylene high-frequency material, with a relative dielectric constant of 2.65 and a loss tangent of 0.001; the dielectric layer is a cube unit with a side length of length 1 =10mm, thickness H 1 =1.5mm.

[0053] like Figure 5 As shown, in a specific implementation, the transmission metasurface module 1 exhibits a structural parameter L-phase relationship in the test, Figure 5 The middle curve represents the transmission phase of the high transmittance phase-modulating unit 4 when the structural parameter L of the quasi-snow spot metal layer 5 of the transmission metasurface module 1 increases from 1 mm to 9 mm in steps of 0.01 mm; the horizontal axis of the relationship diagram is the structural parameter L of the quasi-snow spot metal layer 5, and the vertical axis is the S parameter phase of the high transmittance phase-modulating unit 4 at the center frequency of 10 GHz; it can be seen from the figure that the high transmittance phase-modulating unit 4 has a large phase control capability and can achieve at least 360 degrees of continuous phase adjustment, which lays the foundation for the transmission metasurface module 1 to achieve more functions and larger angles of intelligent control.

[0054] During specific implementation, the operating frequency of the transmission metasurface module 1 is set to 10 GHz, and the high-transmittance phase modulation unit 4 can achieve 360-degree continuous phase adjustment, and has a 16-phase state response capability with high-precision 4-bit control, allowing the transmission metasurface module 1 to achieve efficient control of electromagnetic waves according to the generalized Snell's law.

[0055] like Figure 6 As shown, the microstrip patch antenna 8 is composed of a thin dielectric substrate 9, a rectangular metal patch 10 attached to the top side of the substrate, a square metal patch 11 on the bottom side of the substrate corresponding to the patch, and a feeding coaxial line 12 running through the three, and is combined into an antenna excitation module 2 according to the single feed source, multi-feed source, and phased array modes of the feed source digital control module.

[0056] The dielectric substrate 9 is a F4B polytetrafluoroethylene high-frequency material with a relative dielectric constant of 2.65 and a loss tangent of 0.001. The dielectric substrate 9 is a cube unit with a side length 2 =15mm, thickness H 2 =0.508mm.

[0057] The top metal patch 10 is rectangular, with a length of patchX = 11.9 mm and a width of patchY = 9.8 mm, and its geometric center coincides with the geometric center of the dielectric substrate 9; the bottom metal patch 11 is square and coincides with the bottom of the dielectric substrate 9, with a side length of 2 =15mm; the feeding point of the feeding coaxial line 12 is located at the horizontal offset d of the geometric center of the top side of the antenna 0 =3.42mm.

[0058] Based on the above system, a multi-feed dynamic multi-beam scanning method for transmissive metasurface is implemented, and dynamic multi-beam modulation is performed according to different radiation modes:

[0059] When implementing it, Figure 7 As shown, in the single feed mode, the antenna excitation module 2 is composed of a single microstrip patch antenna 8. The position of the single microstrip patch antenna 8 is selected by the target beam adjustment, and the direction is always perpendicular to the transmission metasurface module 1. The position movement of the microstrip patch antenna 8 includes the front, back, left, right, top and bottom positions relative to the transmission metasurface module 1. The movement distance in each position affects the system beamforming.

[0060] When implementing it, Figure 7As shown, in the multi-feed mode, the antenna excitation module 2 is composed of a plurality of microstrip patch antennas 8. There is no fixed combination pattern for the relative positions between each microstrip patch antenna 8. The number and position selection of the antenna excitation module 2 are selected by the target beam adjustment selection. The orientation is always perpendicular to the transmission metasurface module 1. The position movement includes the front, back, left, right, top and bottom positions relative to the transmission metasurface module 1. The movement distance in each direction affects the beamforming of the system, and the multiple beams will also affect each other.

[0061] When implementing it, Figure 7 As shown, in the phased array mode, the antenna excitation module 2 is composed of a number of microstrip patch antennas 8, which are arranged at equal intervals in a plane to form an array structure. The array element spacing meets the half-wavelength requirement of 15 mm, the operating frequency is 10 GHz, and the array combination shape is adjusted by the target beam scanning range. There is no fixed arrangement pattern requirement such as a rectangular arrangement, which cannot be understood as a limitation on the present invention. The antenna excitation module 2 in the phased array mode is always oriented perpendicular to the transmission metasurface module 1, and the position movement includes the front, back, left, right, top and bottom positions relative to the transmission metasurface module 1. The movement distance in each position affects the beam forming and beam scanning angle of the system.

[0062] like Figure 8 As shown, the feed source digital control module 3 is composed of a number of digital control feed source excitation circuits. During specific implementation, different circuits respond according to three different modes.

[0063] When implementing it, Figure 8 As shown, in the single feed mode, the feed digital control module 3 is only composed of a signal transmission circuit 13, and a single microstrip patch antenna is used as the feed excitation input of the system, which is directly connected to the signal input through the signal transmission circuit 13, and beamforming is achieved by moving the position of the antenna excitation module 2 and combining the electromagnetic environment control capability of the transmission metasurface module 1;

[0064] When implementing it, Figure 8 As shown, in the multi-feed mode, the feed digital control module 3 is composed of a signal transmission circuit 13 and a power division circuit 14, the input end of the power division circuit 14 is connected to the original signal output end, and the output end of the power division circuit 14 is connected to the input end of the unit microstrip patch antenna 8 of the antenna excitation module 2;

[0065] When implementing it, Figure 8As shown, in the phased array mode, the feed digital control module 3 is composed of a signal transmission circuit 13, a plurality of power division circuits 14, a phase shift circuit 15, an amplifier circuit 16, and an attenuation circuit 17. In the feed digital control module 3, the signal excitation is input from the power division circuit 14, the output end of the power division circuit 14 is connected to the input end of the phase shift circuit 15, the output end of the phase shift circuit 15 is connected to the input end of the amplifier circuit 16, the output end of each amplifier circuit 16 is connected to the input end of the attenuation circuit 17, the output end of the attenuation circuit 17 is connected to each microstrip patch antenna unit 8 of the antenna excitation module 2, and the signal is digitally controlled to realize beamforming and output from the microstrip patch antenna.

Claims

1. A multi-feed dynamic multi-beam scanning method for a transmissive metasurface, which performs dynamic multi-beam modulation according to different radiation modes, characterized in that: Specifically: First, the high-transmittance phase modulation unit at each position of the transmission metasurface module determines the transmission compensation phase and amplitude of the unit at that position through the generalized Snell's law, so that the electromagnetic wave signal propagating on one side can be intelligently controlled; Then, dynamic multi-beam modulation is performed in different radiation modes of the feed excitation module; The different radiation modes include a single feed mode, a multi-feed mode and a phased array mode.

2. The multi-feed dynamic multi-beam scanning method for a transmissive metasurface according to claim 1, characterized in that: The dynamic multi-beam modulation in different radiation modes is specifically: (1) The orientation of a single microstrip patch antenna in single feed mode is always perpendicular to the transmissive metasurface array, and dynamic beam deflection of the target beam is achieved by moving the position of the microstrip patch antenna relative to the transmissive metasurface module; (2) The orientations of several microstrip patch antennas in the multi-feed mode are always perpendicular to the transmission metasurface array, and the amplitude and phase excitation coefficients of the antennas remain consistent. Multi-beam generation is achieved by moving the positions of several microstrip patch antennas relative to the transmission metasurface module and the positional relationship between the combined microstrip patch antennas. The positional relationship between microstrip patch antennas includes the relationship between quantity and orientation, and also determines the number and shape of beams generated by the system multi-beam; (3) The orientation of several microstrip patch antennas in the phased array feed mode is always perpendicular to the transmission metasurface array surface. The phased array is an array structure composed of several microstrip patch antennas arranged at equal intervals in a plane, and the array element spacing is half a wavelength. Single beam generation is achieved by moving the position of the antenna excitation module relative to the transmission metasurface module in the phased array mode and changing the amplitude and phase excitation coefficients of several microstrip patch antennas. Several microstrip patch antennas are arranged at equal intervals of half the wavelength to form a phased array feed pattern. By encoding the amplitude and phase excitation coefficients of the microstrip patch antennas and combining them with the transmissive metasurface module, digital beam control is achieved and the dynamic shaping of the beam generated by the system is determined.

3. The multi-feed dynamic multi-beam scanning method for a transmissive metasurface according to claim 2, characterized in that: In the different radiation modes, the position movement of the antenna excitation module includes the front, back, left, right, top and bottom positions relative to the transmission metasurface array, and the movement distance in each position affects the system beamforming.

4. A device for implementing the multi-feed dynamic multi-beam scanning method for a transmissive metasurface as described in claim 1, characterized in that: It includes a transmission metasurface module for transmitting electromagnetic waves and realizing beamforming, an antenna excitation module for radiating electromagnetic waves, and a feed digital control module for dynamic multi-beam generation and control; the antenna excitation module is perpendicular to the transmission metasurface module array, the antenna excitation module and the feed digital control module are electrically connected in sequence according to the mode setting, and different numbers and types of electromagnetic waves are radiated through different modes of the feed digital control module.

5. The multi-feed dynamic multi-beam scanning device according to claim 4, characterized in that: The feed digital control module is composed of a number of digital control feed excitation circuits, which are combined with the antenna excitation module to form three modes, namely single feed mode, multi-feed mode and phased array mode; The single feed mode is composed of only a single microstrip patch antenna as an antenna excitation module, and the placement position of the single microstrip patch antenna is determined according to the focal design position of the transmission metasurface module and the target beam deflection angle; The multi-feed mode is composed of a plurality of microstrip patch antennas as antenna excitation modules and a plurality of power division circuits as feed digital control modules. In this mode, a plurality of microstrip patch antennas are randomly arranged, and the number of microstrip patch antennas is adjusted according to the target beam; the output end of the power division circuit is respectively connected to a plurality of microstrip patch antennas, and the placement position of the microstrip patch antenna is determined according to the focal design position of the transmission metasurface module, the number of target generated beams, and the respective deflection angles of the target beams; The phased array mode is composed of a number of microstrip patch antennas as antenna excitation modules and a number of power division circuits, amplification circuits, phase shift circuits, and attenuation circuits as feed source digital control modules. Each microstrip patch antenna unit is on one side of the transmission metasurface module and has the same orientation as the metasurface. The microstrip patch antennas are arranged at equal intervals in a plane to form an array structure. The array element spacing meets the half-wavelength requirement, and the array combination shape is adjusted according to the target beam scanning range. In the feed excitation module, the signal excitation is input from the power division circuit, the output end of the power division circuit is respectively connected to the input end of the phase shift circuit, the output end of each phase shift circuit is correspondingly connected to the input end of each amplifier circuit, the output end of each amplifier circuit is correspondingly connected to the input end of each attenuation circuit, the output end of each attenuation circuit is correspondingly connected to each microstrip patch antenna unit of the antenna array, and the signal is digitally controlled to realize beamforming and output from the microstrip patch antenna.

6. The multi-feed dynamic multi-beam scanning device according to claim 4, characterized in that: The transmission metasurface module is a rectangular array structure composed of a number of high-transmittance phase-modulation units that are periodically arranged and evenly spaced in a plane.

7. The multi-feed dynamic multi-beam scanning device according to claim 6, characterized in that: The high transmittance phase modulation unit arrangement design follows the generalized Snell's law. The expected compensation phase distribution of the array element at the array element position (x, y) in the array on the E-plane and H-plane deflection is: In the formula, k0=2π / λ0 is the free space wave number at the design frequency, λ0 is the free space wavelength corresponding to the electromagnetic wave frequency; θ0 is the beam deflection angle along the z-axis, and the position is (x0, y0); the distance between the feed source and the metasurface is F.

8. The multi-feed dynamic multi-beam scanning device according to claim 6, characterized in that: The high-transmittance phase-modulating unit is a frequency-selective structure consisting of three intermediate dielectric layers and four metal layers, wherein the four metal layers are separated by the three intermediate dielectric layers, and the metal layers are etched on the dielectric layers, and the three dielectric layers are interconnected by bonding; the metal layer includes a square ring located at the edge and a quasi-snow spot shape located in the center, and 360° continuous transmission phase regulation is achieved by changing the length L of the quasi-snow spot shape.

9. The multi-feed dynamic multi-beam scanning device according to claim 8, characterized in that: The quasi-snow spot shape is obtained by rotating and etching a rectangular metal sheet with a length of L and a width of w at the center of a square ring.

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