Glass substrate metasurface planar transmission array and method of manufacturing an array

Abstract

The application provides a glass substrate metasurface planar transmission array and a manufacturing method of the array, and the glass substrate metasurface planar transmission array comprises: a plurality of array units, the array unit comprises a dielectric substrate and a metal pattern arranged on the dielectric substrate; the metal pattern is arranged as a metal pattern with a cross slot opened at an angle, each array unit adjusts the resonant frequency in a manner of adjusting the size of the metal pattern; and the metal pattern is provided with four T / I metal film pieces on the circumferential side for controlling the phase shift, and each array unit adjusts the phase in a manner of adjusting the size of the T / I metal film piece. The transmission array provided by the application meets the phase coverage of more than 360 degrees of each array unit by using the high-order mode excited between layers through the design change of the pattern size, and the transmission amplitude reaches more than -3db within a certain bandwidth centered at 28.5GHz, and the processing precision is only required to be 20um, so that the array formed has the characteristics of wide passband and good convergence effect.

Description

Technical Field

[0001] The present application belongs to the field of antenna design technology, and more specifically, relates to a glass substrate metasurface planar transmission array and a method for manufacturing the array. Background Art

[0002] With the evolution of wireless communication technology, frequency resources for wireless communications are limited, driving frequency bands towards higher frequencies. 5G frequency bands have already reached the millimeter wave band. However, when millimeter waves (and even higher frequency bands) propagate in locations where line of sight is obstructed, signals have difficulty reaching them, resulting in signal strength failing to reach the demodulation threshold. Metamaterial planar transmission arrays with subwavelength periodic structures can help redirect wireless signals in specific directions, thereby improving wireless network coverage and boosting network signal strength. This is a new, cost-effective and practical solution, particularly for addressing millimeter wave penetration through walls and homes, and is increasingly being used in the wireless communication field. The design of a planar transmission array typically requires: 1. Array element phase coverage greater than 360 degrees; 2. Optimum transmission efficiency within the passband; 3. Optimum passband bandwidth; and 4. A symmetrical structure that is insensitive to polarization direction.

[0003] Based on the above requirements, most of the current transmission metasurfaces with converging functions adopt a multi-layer stacking structure in order to meet the 360-degree phase coverage requirements, and even have strict air cavities between layers. Generally, the thickness of the medium plus the air cavity is required to meet 1 / 4 wavelength so that they can be connected in series layer by layer.

[0004] However, existing transmissive metasurfaces with converging functions are not compact enough overall, have very high requirements for manufacturing and assembly precision, and are difficult to debug. In addition, most of the materials used are PCB boards, which are not light-transmitting. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a glass-based metasurface planar transmission array to solve the problems in the prior art that the existing transmission metasurface with a converging function is not compact enough as a whole, has very high requirements for manufacturing and assembly precision, and is difficult to debug; and the material selection mostly uses PCB boards, which are not light-transmitting.

[0006] To achieve the above objectives, the technical solution adopted in this application is to provide a glass substrate metasurface planar transmission array, comprising:

[0007] A plurality of array units, each comprising a dielectric substrate and a metal pattern disposed on the dielectric substrate;

[0008] The metal pattern is configured as a metal pattern with cross grooves opened diagonally, and each array unit adjusts its own resonant frequency in accordance with the manner of adjusting the specifications of the metal pattern;

[0009] Four T / I-shaped metal thin films are provided around the metal pattern for controlling phase shift, and each of the array units adjusts its phase by adjusting the size of the T / I-shaped metal thin films.

[0010] Optionally, the metal pattern sizes of the array units are different, and the array units form an N×N array.

[0011] Optionally, at least three dielectric substrates are provided, and the plurality of dielectric substrates are stacked on each other; at least two metal patterns are provided, and the at least two metal patterns are respectively sandwiched between the dielectric substrates.

[0012] Optionally, the metal pattern is arranged in a square shape, and the four T / I-shaped metal sheets are respectively arranged at the midpoints of the four sides of the metal pattern and extend toward a side away from the metal pattern;

[0013] The cross groove is opened in the metal pattern at a 45° angle;

[0014] The width of the metal pattern, the length of the T / I-shaped metal film sheet, and the width of the T / I-shaped metal film sheet can be adjusted.

[0015] Optionally, the edge corners of the metal pattern, the T / I-shaped metal film, and the connection between the T / I-shaped metal film and the metal pattern are passivated.

[0016] Optionally, the metal pattern is arranged in a circular shape, and the four T / I-shaped metal film sheets are arranged in pairs opposite to each other and spaced apart on the circumference of the metal pattern, and the T / I-shaped metal film sheets extend toward a side away from the metal pattern;

[0017] The cross groove is opened in the metal pattern at a 45° angle;

[0018] The width of the metal pattern, the length of the T / I-shaped metal film sheet, and the width of the T / I-shaped metal film sheet can be adjusted.

[0019] Optionally, the feature is that each of the dielectric substrates and each of the metal patterns are bonded and fixed by OCR glue, and each of the dielectric substrates and each of the metal patterns are completely fitted together.

[0020] A method for manufacturing a glass substrate metasurface planar transmission array, comprising:

[0021] Selecting a target medium substrate material and testing the material properties of the substrate material;

[0022] The thickness of the dielectric substrate is selected according to the material properties of the substrate material, and the pattern size, period, line width of the array unit and the size of the metal thin film piece are designed on the basis of the dielectric substrate to find the resonance point;

[0023] The length of the top of the T / I metal thin film piece and the arm length of the T / I metal thin film piece are adjusted by equal steps with a certain accuracy, so that the unit structure realizes linear phase shift characteristics, and the phase coverage range is greater than 360 degrees.

[0024] Optionally, after the length of the top of the T / I metal thin film piece and the arm length of the T / I metal thin film piece are adjusted by equal steps with a certain accuracy, so that the unit structure realizes linear phase shift characteristics, and the phase coverage range is greater than 360 degrees, the method further comprises:

[0025] The array size NxN and the focal length are determined, the required phase of each array unit at a specified position of the array is calculated, and the array units are arranged, so as to realize the converging function of the incident electromagnetic wave.

[0026] The glass substrate metasurface planar transmission array provided by the application has the beneficial effects that compared with the prior art, by changing the design of the pattern size, the glass substrate metasurface planar transmission array provided by the application utilizes the high-order mode excited between layers to meet the phase coverage of each array unit of more than 360 degrees, and in a certain bandwidth centered at 28.5 GHz, the transmission amplitude reaches more than -3db, and the processing precision is only 20um, so that the array has the characteristics of wide passband and good converging effect. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0028] Figure 1 A structure diagram of a glass substrate metasurface planar transmission array provided by an embodiment of the application Figure 1 ;

[0029] Figure 2 A structure diagram of a glass substrate metasurface planar transmission array provided by an embodiment of the application Figure 2 ;

[0030] Figure 3 A schematic diagram of S21 amplitude-frequency characteristic curves of all array elements constituting 360-degree coverage

[0031] Figure 4This is a schematic diagram of the polar coordinate form of S21 at 25GHz;

[0032] Figure 5 This is a schematic diagram of the polar coordinate form of S21 at 28.5GHz;

[0033] Figure 6 This is a schematic diagram of the polar coordinate form of S21 at 31GHz;

[0034] Figure 7 Schematic diagram of plane lens focusing;

[0035] Figure 8 It is the top view of the transmission array;

[0036] Figure 9 This is the array convergence effect diagram;

[0037] Figure 10 Schematic diagram of another glass substrate metasurface planar transmission array provided in an embodiment of the present application Figure 1 ;

[0038] Figure 11 Schematic diagram of another glass substrate metasurface planar transmission array provided in an embodiment of the present application Figure 2 ;

[0039] Figure 12 A schematic structural diagram of another glass substrate metasurface planar transmission array provided in an embodiment of the present application.

[0040] Among them, the reference numerals in the figures are:

[0041] 10-array unit;

[0042] 11- dielectric substrate;

[0043] 12-Metal pattern;

[0044] 121-cross slot;

[0045] 122-T / I metal film sheet. DETAILED DESCRIPTION

[0046] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0047] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0048] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0050] See also Figures 1-12 The glass-based metasurface planar transmission array provided in an embodiment of the present application is now described. This embodiment of the present application provides a glass-based metasurface planar transmission array 11, comprising a plurality of array units 10. The array units 10 include a dielectric substrate 11 and a metal pattern disposed on the dielectric substrate 11. The dielectric substrate 11 is typically made of a dielectric material, such as glass, which has the advantages of good light transmittance and high hardness, enabling both visible light and electromagnetic wave transmission through the same glass material. When glass is used as the dielectric substrate 11, the dielectric constant of the glass material typically varies widely, ranging from approximately 3 to 10, and the loss of different glass types is also relatively high. For example, in the millimeter wave band, the Dk of typical soda-lime glass is approximately 7, and the Df reaches 0.02 or even higher. Furthermore, because the millimeter wave band also requires high thickness and process uniformity of the glass substrate, these factors greatly increase the difficulty of designing transparent planar transmission arrays in the millimeter wave band, making it difficult to find large-scale transparent transmission array products. In the present application, a metal pattern is provided on a dielectric substrate 11, and the metal pattern is provided as a metal pattern 12 having a cross groove 121 opened diagonally. Each array unit 10 adjusts its respective resonant frequency by adjusting the specifications of the metal pattern 12; four T / I-shaped metal film sheets 122 for controlling phase shift are provided on the circumferential side of the metal pattern 12, and each array unit adjusts its respective phase by adjusting the size of the T / I-shaped metal film sheet 122.

[0051] Based on the above embodiment, optionally, at least three dielectric substrates 11 are provided, with multiple dielectric substrates 11 stacked one on top of the other, and at least two metal patterns 12 are provided, with at least two metal patterns 12 sandwiched between each dielectric substrate. The double-layer metal pattern 12 is distributed on the interlayer plane on both sides of the inner glass layer. The outer dielectric substrate 11 not only participates in determining the resonance related to the material properties but also protects the metal pattern 12. A relatively regular metal pattern 12 is designed on the surface of the dielectric substrate 11. By varying the design size of the pattern and utilizing the high-order modes excited between layers, the phase coverage of each array element is achieved to exceed 360 degrees. Within a certain bandwidth centered at 28.5 GHz, the transmission amplitude is consistently above -3 dB. The machining accuracy requires only 20 μm, resulting in an array with a wide bandwidth and good focusing effect.

[0052] Specifically, the basic elements of the metal pattern are composed of an oscillation control unit, a broadband enhancement unit, and a phase shift control unit. Among them, the oscillation control unit and the broadband enhancement unit are usually composed of a metal pattern 12 and a cross slot 121 arranged in the middle part. By adjusting the size of the metal pattern, the resonance point of the array unit 10 can be adjusted. Correspondingly, the phase shift control unit is composed of four T / I-shaped metal film sheets 122 arranged on the side of the metal pattern 11. The T / I-shaped metal film sheets 122 are increased and adjusted according to certain rules to achieve phase adjustment of the array unit 10; accordingly, the dual resonant circuit formed by the two resonant points has a relatively wide bandwidth. Usually, the size of the center patch determines the high end of the passband, and the width of the cross slot on the center patch controls the low end of the passband. The design is relatively convenient and the passband width is relatively wide.

[0053] In this embodiment, according to the requirements of glass medium thickness, dielectric constant, etc., 1 / 2-1 / 3 of the wavelength is generally selected as the unit period, and the width LG of the cross groove 121 set on the metal pattern 12 is 0.06 mm, which is a fixed parameter. Accordingly, when the length Lc and width Lb of the T / I-shaped metal film sheet 122 are minimized, the size of the metal pattern 12 is adjusted to achieve the starting frequency, where the starting frequency is 2 GHz higher than the center frequency. After reaching the starting point, the adjustment of the metal pattern 12 is stopped, and the size of the metal pattern 12 is kept unchanged. From this point on, the length Lc and width Lb of the four groups of T / I-shaped metal film sheets 122 are adjusted independently or jointly, so that a phase coverage of more than 360 degrees can be combined. Therefore, the sizes of the pattern parts of each array unit 10 can be different, and can be adjusted from, for example Figure 1 The three dimensions La, Lb, and Lc shown are flexibly adjusted to meet the array's phase requirements for that element position.

[0054] On the basis of the above embodiment, in order to meet the requirements of array arrangement, the array units at each position of the array are individually adjusted to achieve a phase distribution of 360 degrees or more. Optionally, the sizes of the array units 10 are different, and the array units 10 form an N×N array. The required phase is calculated using the focusing equations of different array units 10. Then, within the corresponding array unit set, a unit with a size close to the phase and meeting the bandwidth requirements is found. The unit module is placed in a specified position of the array and arranged. The above selection is performed on all array elements of the N×N array to achieve the focusing function of the incident electromagnetic wave.

[0055] Based on the above embodiments, the shape of the metal pattern 12 can be set to be square, circular, and various irregular shapes to achieve better performance.

[0056] For example, in one embodiment of the present application, Figures 1-2 As shown, the metal pattern 12 is set to be square, and four T / I-shaped metal film sheets 122 are respectively arranged at the midpoints of the four sides of the metal pattern 12 and extend toward the side away from the metal pattern 12; the cross groove 121 is opened at 45° in the metal pattern 12; the width La of the metal pattern 12, the length Lc of the T / I-shaped metal film sheet 122 and the width Lb of the T / I-shaped metal film sheet 122 can be adjusted.

[0057] Specifically, in this embodiment, the period of the array unit 10 is P = 4.08 mm, and the width of each microstrip line (i.e., the portion of the microstrip line connecting the metal pattern 12 and the T / I-shaped metal film sheet 122) is W = 0.3 mm; the T / I-shaped metal sheet 122 diverges outward from the center of the four sides of the array unit, and its arm length Lc can be changed; when Lc changes to a certain extent, the I-shaped structure is deformed into a T-shaped structure. At this time, the length of the top of the T-shape is Lb, which can be adjusted within a certain range to help achieve a phase distribution of 360 or more; the glass substrate is Corning Eagle glass, with a dielectric constant of approximately 5.3, a loss tangent of 0.01, and a thickness of 1.3 mm.

[0058] like Figure 3 As shown, Figure 3 The S21 amplitude-frequency characteristic curves corresponding to the size change of the array unit of the structure, these curves cover 360 degrees (see Figures 4-6 ), it can be seen that from 25GHz to 31GHz, the amplitude drop within the passband does not exceed 3dB. Figures 4-6 In the figure, the polar coordinates of S21 corresponding to the three frequency points of 25GHz, 28.5GHz and 31GHz are displayed on the graph. The phase coverage can reach 360 degrees or above, and the overall amplitude is high and stable, which meets the phase requirements when designing the focusing array and can achieve a good convergence effect.

[0059] In this embodiment, the design utilizes only two layers of the same metal coating. To avoid the prior art problem of requiring strict air cavities between layers to meet 360-degree phase coverage requirements, which generally requires the dielectric plus air cavity thickness to meet 1 / 4 wavelength for layer-by-layer cascade connection and results in an overall lack of compactness, each dielectric substrate 11 and each metal pattern 12 are optionally bonded and fixed using OCR glue, with each dielectric substrate 11 and each metal pattern 12 fully bonded. The use of glue to fully bond the metal pattern to the glass dielectric avoids the need for highly precise air cavities. Even if the metal coating utilizes a transparent conductive ITO film, a converged array effect can be achieved, resulting in complete transparency and simplified fabrication, making it easy to extend to various application scenarios and readily available. Furthermore, the design of this embodiment of the present application utilizes two resonant points to form a dual resonant circuit, allowing for a relatively wide bandwidth. Typically, the size of the center patch determines the high end of the passband, while the cross slot on the center patch controls the low end of the passband. This design is relatively convenient and results in a wide passband width. The I / T-shaped portion adjusts the phase, slowly varying from small to large, allowing for phase coverage exceeding 360 degrees. It exhibits excellent linearity and monotonicity, resulting in robustness. Even material variations only cause phase shifts in the same direction. By effectively combining square patches, cross slots, and I / T-shaped patterns, the design achieves a bandwidth exceeding 5-6 GHz with minimal intra-band fluctuations. Careful adjustment can reduce the overall intra-band loss to less than 3 dB. The high similarity among all patterns facilitates array deployment.

[0060] In another embodiment provided in the present application, the metal pattern 12, the T / I metal sheet 122, and the edge corners of the connection between the T / I metal film sheet 122 and the metal pattern 12 are optionally passivated. Figure 12 As shown, based on the above embodiment, and with the same parameters as the above embodiment, this embodiment will not be described in detail. Specifically, the edge angles of the metal pattern 12, the T / I-shaped metal film 122, and the connection between the T / I-shaped metal film 122 and the metal pattern 12 are blunted to further optimize the performance of the present application and achieve a better converged array effect.

[0061] Alternatively, as in another embodiment provided by the present application, Figure 10 、 Figure 11 As shown, optionally, the metal pattern 12 is set to be circular, and four T / I-shaped metal film sheets 122 are arranged in pairs opposite to each other and at intervals on the circumference of the metal pattern 12, and the T / I-shaped metal film sheets 122 extend toward the side away from the metal pattern 12; the cross groove 121 is opened at 45° in the metal pattern 12; the width La of the metal pattern 12, the length Lc of the T / I-shaped metal film sheet 122 and the width Lb of the T / I-shaped metal film sheet 122 can be adjusted.

[0062] Specifically, in this embodiment, the period of the array unit 10 is P = 4.08 mm, and the width of each microstrip line (i.e., the portion of the microstrip line connecting the metal pattern 12 and the T / I-shaped metal film sheet 122) is W = 0.3 mm; the T / I-shaped metal film 122 radiates outward from the center of the four sides of the array unit 10, and its arm length Lc can be changed; when Lc changes to a certain extent, the I-shaped structure is deformed into a T-shaped structure. At this time, the length of the top of the T-shape is Lb, which can be adjusted within a certain range to assist in achieving a phase distribution of 360 or more; the glass substrate is Corning Eagle glass, with a dielectric constant of approximately 5.3, a loss tangent of 0.01, and a thickness of 1.3 mm.

[0063] The present application also provides a method for manufacturing a glass substrate metasurface planar transmission array, comprising:

[0064] S100: Select the target dielectric substrate material, such as quartz glass, ceramics, polymer materials, etc., and test the material properties of the substrate material, such as dielectric constant and loss tangent.

[0065] S200: The thickness of the dielectric substrate is selected based on the material properties of the substrate, and parameters such as the pattern size, period, line width, and size of the metal sheet of the array unit are designed based on the dielectric substrate to find the starting point of the array unit;

[0066] S300: Adjust the top length Lb of the T / I-shaped metal sheet and the arm length Lc of the T / I-shaped metal film sheet with a certain precision (such as 20 μm) so that the unit structure achieves a linear phase shift characteristic and a phase coverage range greater than 360 degrees. At the same time, a certain transmittance is guaranteed, and a set of array element sizes with S21 phase coverage of 360 degrees is obtained.

[0067] After adjusting the top length of the T / I-shaped metal sheet and the arm length of the T / I-shaped metal sheet with a certain precision and equal steps so that the unit structure achieves a linear phase shift characteristic and the phase coverage range is greater than 360 degrees, the following is also included:

[0068] S400: Determine the array size NxN and focal length, calculate the required phase for the array unit at each specified position of the array and arrange them to achieve the function of converging the incident electromagnetic waves.

[0069] Specifically, the phase calculation is achieved through the following array focusing equation. In the aforementioned S21 phase set, the unit corresponding to the size that is close to the phase and meets the bandwidth requirements is found. The unit module is placed in the specified position of the array and arranged. The above selection is performed on all array elements of the NxN array to achieve the focusing function of the incident electromagnetic wave.

[0070] Let the plane wave be perpendicular incident, the angle deflection of the beam convergence point be theta and phi, (x, y) be the coordinates of the center of each array element on the array surface, NxN be the array size, focus be the focal length, be the distance from the focal point to the center of the array surface, and the coordinates of the focal point be converted to:

[0071]

[0072]

[0073] zf = focus*cos(theta)

[0074] Then the phase of each array element satisfies the following constraint condition:

[0075]

[0076] Lambda0 is the wavelength in free space corresponding to the center frequency. The convergence principle is shown in the schematic Figure 7 .

[0077] Further, for example, a 9x9 array is designed, the focal point is 31.6mm, the focal ratio F / D = 0.86, and the effect after arraying is as shown in Figure 8 In the XOY plane at the focal point, the array convergence effect is as shown in Figure 9 It can be seen that the electric field energy is converged to the focal point.

[0078] On the basis of the above embodiment, the application further provides an antenna, comprising an antenna body and the glass substrate metasurface planar transmission array. Wherein, the glass substrate metasurface planar transmission array provided in the embodiment has the same structure as the glass substrate metasurface planar transmission array provided in the above embodiment, and has the same technical effect, and the embodiment of the application does not make redundant description.

[0079] The above is only a preferred embodiment of the application, and does not limit the application, any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A glass substrate metasurface planar transmission array, characterized in that: include: A plurality of array units, each comprising a dielectric substrate and a metal pattern disposed on the dielectric substrate; By changing the design of the pattern size and utilizing the high-order modes excited between layers, the phase coverage of each array unit can reach more than 360 degrees. The metal pattern is configured as a metal pattern with cross grooves opened diagonally, and each array unit adjusts its own resonant frequency in accordance with the manner of adjusting the specifications of the metal pattern; Four T / I-shaped metal thin films are provided on the periphery of the metal pattern for controlling phase shift, and each of the array units adjusts its phase by adjusting the size of the T / I-shaped metal thin films; The edge corners of the metal pattern, the T / I-shaped metal film, and the connection between the T / I-shaped metal film and the metal pattern are passivated; At least three dielectric substrates are provided, and the plurality of dielectric substrates are stacked on each other; There are at least two metal patterns, and the at least two metal patterns are respectively sandwiched between the dielectric substrates; The metal pattern is arranged in a square shape, and the four T / I-shaped metal thin films are respectively arranged at the midpoints of the four sides of the metal pattern and extend toward a side away from the metal pattern; The cross groove is opened in the metal pattern at a 45° angle; The width of the metal pattern, the length of the T / I-shaped metal film sheet, and the width of the T / I-shaped metal film sheet can be adjusted.

2. The glass substrate metasurface planar transmission array according to claim 1, wherein: The array units have different sizes, and the array units form an N×N array.

3. The glass substrate metasurface planar transmission array according to claim 1 or 2, wherein: Each dielectric substrate and each metal pattern are bonded and fixed by OCR glue, and each dielectric substrate and each metal pattern are completely adhered to each other.

4. A method for manufacturing a glass substrate metasurface planar transmission array according to any one of claims 1 to 3, characterized in that: include: Selecting a target medium substrate material and testing the material properties of the substrate material; The thickness of the dielectric substrate is selected according to the material properties of the substrate, and the pattern size, period, line width of the array unit and the size of the metal film are designed based on the dielectric substrate to find the starting point of the metal film; The top length of the T / I-shaped metal film and the arm length of the T / I-shaped metal sheet are adjusted with a certain precision and equal steps so that the unit structure can achieve linear phase shift characteristics and the phase coverage range is greater than 360 degrees.

5. The method for manufacturing a glass substrate metasurface planar transmission array according to claim 4, wherein: After adjusting the top length of the T / I-shaped metal film and the arm length of the T / I-shaped metal film with a certain precision and equal steps so that the unit structure achieves a linear phase shift characteristic and the phase coverage range is greater than 360 degrees, the method further includes: Determine the array size NxN and focal length, calculate the required phase for the array elements at each specified position of the array and arrange them to achieve the focusing function of the incident electromagnetic waves.

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