Sub-wavelength structural unit and preparation method thereof, reflective array and broadband planar film antenna

Abstract

The invention provides a sub-wavelength structure unit and a preparation method thereof, a reflective array and a broadband planar film antenna, and the sub-wavelength structure unit comprises a sub-wavelength structure, a metal reflective layer, a first film and a second film. The sub-wavelength structure comprises at least two types of single resonant structures; the at least two types of single resonance structures are arranged on the first thin film; the metal reflecting layer is arranged on the second thin film; a spacing layer is arranged between the first film and the second film; and the phase and dispersion characteristics of the sub-wavelength structure unit in the first resonance area and / or the second resonance area are determined by setting parameters of the single resonance structure. According to the invention, the sub-wavelength structure comprises multiple types of single-resonant structures for forming different multi-resonant sub-wavelength structures, so that the problem of narrow bandwidth of a single-layer film antenna formed by the sub-wavelength structure unit can be solved.

Description

Technical Field

[0001] The present application relates to the field of antennas, and more specifically, to a subwavelength structural unit and a preparation method thereof, a reflective array, and a broadband planar thin film antenna. Background Art

[0002] Subwavelength structural units are becoming a research hotspot in the fields of advanced materials science and micro-nanofabrication. These microstructures, characterized by their characteristic dimensions smaller than the wavelength of the light they interact with, exhibit unique and exceptional optical, electromagnetic, and other physical properties, offering enormous potential for applications in a wide range of high-tech fields, including super-resolution imaging, integrated photonic devices, invisibility cloaking, and high-efficiency solar cells.

[0003] However, the dispersion properties of subwavelength structural units result in narrow operating bandwidths for planar thin-film antennas constructed from them. Traditional approaches have employed multilayer film structures to overcome this narrow bandwidth. However, this approach introduces a new technical challenge: multilayer alignment. Due to the delicate structural dimensions required, achieving the desired functionality often requires stacking and combining multiple layers of material. However, achieving high-precision alignment of these multiple layers is extremely challenging in actual design and fabrication. Summary of the Invention

[0004] In view of this, the purpose of the embodiments of the present application is to provide a subwavelength structural unit and a preparation method, a reflective array, and a broadband planar thin film antenna, which can avoid the problem of interlayer alignment of the subwavelength structural unit and reduce the difficulty of manufacturing and designing the subwavelength structural unit.

[0005] In a first aspect, an embodiment of the present application provides a subwavelength structure unit, comprising: a subwavelength structure, a metal reflective layer, a first film, and a second film; wherein the subwavelength structure comprises: at least two types of single resonant structures; at least two types of the single resonant structures are arranged on the first film; the metal reflective layer is arranged on the second film; a spacer layer is arranged between the first film and the second film; wherein the phase and dispersion characteristics of the subwavelength structure unit in the first resonant region and / or in the second resonant region are determined by the set parameters of the single resonant structure.

[0006] In the above implementation, by configuring the subwavelength structure to include multiple types of single-resonance structures, the subwavelength structural units resonate within different frequency ranges, thereby overcoming the narrow bandwidth problem of single-layer thin-film antennas formed by the subwavelength structural units. This improves the bandwidth of single-layer thin-film antennas formed by the subwavelength structural units while also avoiding interlayer alignment issues, reducing the difficulty in fabricating and designing the subwavelength structural units. Furthermore, by using a thin-film substrate, the subwavelength structural units can be designed to be lightweight.

[0007] In one embodiment, the single resonant structures are of three types, including: a first single resonant structure, a second single resonant structure, and a third single resonant structure; wherein the phase and dispersion characteristics of the subwavelength structure unit in the first resonant region are determined by the size of the first single resonant structure; the phase and dispersion characteristics of the subwavelength structure unit in the second resonant region are determined by the size of the second single resonant structure; and the phase and dispersion characteristics of the subwavelength structure unit in the third resonant region are determined by the capacitance value and size of the third single resonant structure.

[0008] In the above implementation process, by setting the first single resonant structure, the second single resonant structure and the third single resonant structure, a multi-resonant mode can be formed, thereby adjusting the phase and dispersion characteristics of different frequency regions of the subwavelength structure unit, thereby improving the flexibility and accuracy of adjusting the phase and dispersion characteristics of the subwavelength structure unit.

[0009] In one embodiment, the third single resonant structure includes a first patch along a first direction, a second patch arranged along a second direction, and a capacitor; wherein the first patch and the second patch are perpendicular; the capacitor is arranged on the first patch and / or the second patch, and the capacitor is located at the separation of the first patch and / or the second patch; wherein the phase and dispersion characteristics of the subwavelength structure unit in the third resonant region are determined by the capacitance value of the capacitor and the size of the first patch and the second patch.

[0010] In one embodiment, the first single resonant structure includes a third patch and a fourth patch arranged along a first direction, and a fifth patch and a sixth patch arranged along a second direction; wherein the third patch is parallel to the fourth patch, and the fifth patch is parallel to the sixth patch; the first patch is arranged between the fifth patch and the sixth patch, and is perpendicular to the fifth patch and the sixth patch; the second patch is arranged between the third patch and the fourth patch, and is perpendicular to the third patch and the fourth patch.

[0011] In one embodiment, the second single resonant structure includes a seventh patch and an eighth patch arranged along a first direction, and a ninth patch and a tenth patch arranged along a second direction; wherein the seventh patch is parallel to the eighth patch, the ninth patch is parallel to the tenth patch, and the seventh patch and the eighth patch are perpendicular to the ninth patch and the tenth patch.

[0012] In the above implementation, the first single resonant structure includes a first patch, a second patch, and a capacitor; the second single resonant structure includes a third patch, a fourth patch, a fifth patch, and a sixth patch; and the third single resonant structure includes a seventh patch, an eighth patch, a ninth patch, and a tenth patch. That is, the first, second, and third single resonant structures are formed by a few patches and / or capacitors, resulting in a simple structure that is easy to implement and simplifies the structure of the subwavelength structure unit.

[0013] In one embodiment, the spacer layer is a gas layer and / or a dielectric layer; the subwavelength structure unit further comprises: a bracket; a side of the first film away from the subwavelength structure and the metal reflective layer are connected via the bracket.

[0014] In the above implementation process, by setting the spacer layer as a gas layer and / or a dielectric layer, according to the microstrip transmission line theory, the gas layer and / or the dielectric layer are introduced into the overall structure, thereby increasing the Q value and improving the resonance bandwidth.

[0015] In a second aspect, an embodiment of the present application further provides a reflective array, comprising: a plurality of sub-wavelength structural units in the first aspect, or any one of the first aspects, arranged in an array surface arrangement manner; wherein the lateral arrangement interval and / or longitudinal arrangement interval between adjacent sub-wavelength structural units is less than half a wavelength.

[0016] In the above implementation process, a reflective array is constructed by arranging multiple sub-wavelength structural units in an array plane, which can expand the bandwidth of the reflective array and thereby improve the bandwidth of the reflective array.

[0017] In a third aspect, an embodiment of the present application further provides a broadband planar thin film antenna, comprising: a feed antenna and a reflective array according to the second aspect; the feed antenna is arranged on one side of the reflective array; wherein the feed antenna is configured to transmit electromagnetic waves to the reflective array and / or receive the electromagnetic waves reflected by the reflective array.

[0018] In the above implementation process, by setting the broadband planar film antenna to include a reflective array, and the reflective array includes multiple sub-wavelength structural units arranged according to the array surface arrangement, the bandwidth of the broadband planar film antenna can be expanded and the bandwidth of the broadband planar film antenna can be increased.

[0019] In one embodiment, the feed antenna includes one of a patch antenna, a standard waveguide, a slot antenna, and a Vivaldi antenna.

[0020] In the above implementation process, by setting the feed antenna to include one of the patch antenna, standard waveguide, slot antenna, and Vivaldi antenna, the corresponding feed antenna can be selected according to actual needs, thereby increasing the flexibility of feed antenna selection and increasing the application scenarios of the broadband planar thin film antenna.

[0021] In a fourth aspect, an embodiment of the present application also provides a method for preparing a subwavelength structure unit, including: determining the first setting parameters of the target single resonant structure and / or the second setting parameters of the target capacitance of each resonant region according to the operating frequency of each resonant region of the subwavelength structure unit and the set resonance formula; preparing the target single resonant structure on a first film according to the first setting parameters; separating one or more regions in one or more target single resonant structures; setting the target capacitance on the side away from the first film at the separation of one or more target single resonant structures according to the second setting parameters; preparing a metal reflective layer on a second film; arranging the first film and the second film on opposite sides of the spacer layer; or, determining the first setting parameters of the target single resonant structure of each resonant region according to the operating frequency of each resonant region of the subwavelength structure unit and the set resonance formula; preparing the target single resonant structure on a first film according to the first setting parameters; preparing a metal reflective layer on a second film; and arranging the first film and the second film on opposite sides of the spacer layer.

[0022] In order to make the above-mentioned objectives, features and advantages of the present application more obvious and easy to understand, the following embodiments are given in conjunction with the accompanying drawings for detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 A schematic structural diagram of a sub-wavelength structural unit provided in an embodiment of the present application;

[0025] Figure 2 A schematic plan view of a sub-wavelength structural unit provided in an embodiment of the present application;

[0026] Figure 3 A schematic diagram of the electromagnetic performance simulation results of the sub-wavelength structural unit provided in the embodiment of the present application;

[0027] Figure 4 A schematic diagram of the structure of a reflector array provided in an embodiment of the present application;

[0028] Figure 5 A schematic structural diagram of a broadband planar film antenna provided in an embodiment of the present application;

[0029] Figure 6 A schematic diagram of experimental test results of the directional pattern of a broadband planar film antenna provided in an embodiment of the present application;

[0030] Figure 7 A schematic diagram of the gain test results of a broadband planar thin film antenna provided in an embodiment of the present application;

[0031] Figure 8 A flow chart of a method for preparing a sub-wavelength structural unit provided in an embodiment of the present application;

[0032] Figure 9 A flow chart of another method for preparing a sub-wavelength structural unit provided in an embodiment of the present application.

[0033] Description of the drawings: 10-subwavelength structure unit, 100-subwavelength structure, 110-third single resonant structure, 111-first patch, 112-second patch, 120-first single resonant structure, 123-third patch, 124-fourth patch, 125-fifth patch, 126-sixth patch, 130-second single resonant structure, 137-seventh patch, 138-eighth patch, 139-ninth patch, 131-tenth patch, 140-capacitor, 200-metal reflective layer, 300-first film, 400-second film. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application.

[0035] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0036] As a key payload component of satellites, spaceborne antennas play a vital role in deep space communications, space-based Earth observation, and other fields. Existing spaceborne antenna structures mostly use parabolic antennas and flat-panel phased array antennas. Parabolic antennas achieve high gain through a curved surface design, which requires high surface precision, is difficult to control, and requires a complex surface-maintaining mechanism. Flat-panel phased array antennas achieve high gain through unit arrays, requiring a complex feed network and facing the challenges of large size and weight. With the development of related fields, existing technologies are unable to meet the development trend of large-diameter and lightweight spaceborne antennas.

[0037] The sub-wavelength structured planar array antenna achieves the beam-forming capability of the curved surface through the structural phase modulation mechanism, avoiding the problems of difficult surface control and complex feeding in traditional technical means, and providing a new technical approach for the construction of satellite-borne antennas.

[0038] However, the dispersion properties of subwavelength materials result in a narrow operating bandwidth for planar array antennas. Multilayer subwavelength structures can expand the antenna's bandwidth, but to avoid interlayer coupling effects that could distort the wavefront response, high alignment accuracy is required. Multilayer thin-film design presents significant engineering challenges. To meet lightweight requirements, broadband planar thin-film antennas are becoming a trend in spaceborne antennas.

[0039] In view of this, the present application proposes a sub-wavelength structural unit. By setting at least two types of single resonant structures, the sub-wavelength structural unit produces resonance in different frequency ranges, thereby forming a wide-band, lightweight broadband planar thin-film antenna. The structural design of the sub-wavelength structural unit avoids the problem of inter-layer alignment and reduces the difficulty of manufacturing and designing the sub-wavelength structural unit.

[0040] To facilitate understanding of this embodiment, the sub-wavelength structural unit disclosed in the embodiment of the present application is first introduced in detail.

[0041] like Figure 1 , which is a schematic structural diagram of a subwavelength structural unit, includes: a subwavelength structure 100, a metal reflective layer 200, a first film 300 and a second film 400. The subwavelength structure 100 includes: at least two types of single resonant structures.

[0042] The subwavelength structure 100 is disposed on the first film 300 ; the metal reflective layer 200 is disposed on the second film 400 ; and a spacer layer is disposed between the first film 300 and the second film 400 .

[0043] Optionally, the thickness of the spacer layer between the first film 300 and the second film 400 can be 7 mm, 8 mm, 9 mm, etc., and the thickness of the spacer layer can be selected based on actual conditions. According to microstrip transmission line theory, the introduction of a spacer layer (e.g., an air layer or a dielectric layer) between the first film 300 and the second film 400 can increase the Q value and improve the resonant bandwidth. In one embodiment, the dielectric constant of the dielectric in the spacer layer is greater than or equal to 1.0.

[0044] The subwavelength structure 100 is a two-dimensional artificial structure with unique electromagnetic properties. The subwavelength structure 100 has the following characteristics: the unit dimensions (such as period, width, thickness, etc.) of the structure are significantly smaller than the operating wavelength; the entire structure is composed of only a single layer of material, and the thickness is much smaller than the wavelength.

[0045] In one embodiment, the sub-wavelength structure 100 is a composite structure composed of multiple metal structures (eg, metal patches).

[0046] Optionally, the subwavelength structure 100 may be a ring shape such as a square ring, a rectangular ring, or a circular ring, or may be an open shape such as an "I" shape, a "W" shape, or an open rectangle. The shape of the subwavelength structure 100 may be selected according to actual conditions.

[0047] The metal reflective layer 200 is a thin film or coating made of a metal material, which is mainly used to reflect light (especially light of a specific wavelength band) or electromagnetic waves, and has the characteristics of high reflectivity and low absorptivity. For example, silver, aluminum, gold, copper, etc. can be selected according to actual conditions.

[0048] Optionally, the metal structure in the sub-wavelength structure 100 and the metal structure in the metal reflective layer 200 may be made of the same metal or different metals.

[0049] Optionally, the material of the first film 300 includes one or more of PET film, PMMA film, PI film, PS film, etc., and the material of the second film 400 includes one or more of PET film, PMMA film, PI film, PS film, etc. The materials of the first film 300 and the second film 400 can be selected according to actual conditions.

[0050] The dielectric constant of the first film 300 and / or the second film 400 is greater than or equal to 2.0. For example, 2.1, 3.5, etc. The dielectric constant of the first film 300 and / or the second film 400 can be selected according to actual conditions. At least two types of single resonant structures are disposed on the first film 300.

[0051] The single resonant structure here is a basic resonant circuit or mechanical structure that can produce resonance at a specific frequency.

[0052] Optionally, the single resonant structure may be annular or open, for example, a circular ring, a square, a double-sided ring, a Phoenix unit, a matrix, a circle, an I-shaped, a X-shaped, a W-shaped, etc. The shape of the single resonant structure may be selected according to actual conditions.

[0053] It should be understood that the above-mentioned single resonance structure can achieve multi-resonance by nesting square rings, multiple microstrip lines, etc.

[0054] The phase and dispersion characteristics of the above-mentioned sub-wavelength structure unit 10 in the first resonance region and / or the second resonance region are determined by setting parameters of the single resonance structure.

[0055] The set parameters may include parameters such as the size of the single resonant structure and the capacitance of the single resonant structure. The size of the single resonant structure may include the side length and width of the single resonant structure, and the size of the single resonant structure may be selected based on actual conditions. The capacitance of the single resonant structure may refer to the capacitance value of capacitor 140.

[0056] It should be understood that by providing at least two types of single resonant structures in the subwavelength structure 100 and by appropriately combining the at least two types of single resonant structures, a multi-resonant mode can be formed.

[0057] By adjusting the size of the single resonant structure, the phase of the resonant region of the sub-wavelength structure 100 can be controlled.

[0058] Optionally, the single resonant structures used to form multiple resonances can be of multiple types. For example, there can be two, three, four, or five types. A greater variety of single resonant structures can achieve a greater variety of resonance modes and dispersion control. The embodiments of this application do not limit the number or arrangement of single resonant structures used to form multiple resonances.

[0059] In the above implementation, by configuring the subwavelength structure 100 to include multiple types of single-resonance structures, the subwavelength structural units resonate within different frequency ranges, overcoming the narrow bandwidth problem of single-layer thin-film antennas formed from conventional subwavelength structural units. This improves the bandwidth of single-layer thin-film antennas formed from subwavelength structural units while also avoiding inter-layer alignment issues, reducing the difficulty in fabricating and designing the subwavelength structural units. Furthermore, by configuring the substrate as a thin film substrate, a lightweight design of the subwavelength structural units can be achieved.

[0060] In a possible implementation, the overall structure formed by at least two types of single resonant structures is symmetrical along the center line of the first film 300 .

[0061] In the above implementation process, by combining the two types of single-resonance structures into a multi-resonance structure, the overall multi-resonance structure is rotationally symmetric, which can achieve polarization-independent characteristics and improve the stability of the subwavelength structure unit.

[0062] In a possible implementation, there are three types of single resonant structures, including: a third single resonant structure 110 , a first single resonant structure 120 , and a second single resonant structure 130 .

[0063] The third single resonant structure 110, the first single resonant structure 120, and the second single resonant structure 130 are all disposed on the first film 300; the third single resonant structure 110 and the first single resonant structure 120 are disposed orthogonally, and the third single resonant structure 110 and / or the first single resonant structure 120 are disposed around the second single resonant structure 130.

[0064] In one embodiment, the phase and dispersion characteristics of the subwavelength structure unit 10 in the first resonance region are determined by the size of the first single resonant structure 120; the phase and dispersion characteristics of the subwavelength structure unit 10 in the second resonance region are determined by the size of the second single resonant structure 130; and the phase and dispersion characteristics of the subwavelength structure unit 10 in the third resonance region are determined by the size and capacitance value of the third single resonant structure 110.

[0065] In one embodiment, the third single resonant structure 110 and the first single resonant structure 120 are open structures, and the second single resonant structure 130 is a closed structure.

[0066] The first resonance region is a high frequency region, the second resonance region is a medium frequency region, and the third resonance region is a low frequency region.

[0067] It should be understood that by disposing the first single resonant structure 120, the second single resonant structure 130, and the third single resonant structure 110 on the first film 300, the coupling between adjacent resonant modes affects the phase response of each single resonant structure, thereby increasing the complexity of the aperture design. To address this issue, a particle swarm optimization algorithm can be used to accurately compensate for dispersion errors, optimize the overall phase distribution, and improve design accuracy.

[0068] In the above implementation, by providing the first single resonant structure 120, the second single resonant structure 130, and the third single resonant structure 110, a multi-resonant mode can be formed, thereby adjusting the phase and dispersion characteristics of the subwavelength structure unit 10 in different frequency regions, thereby improving the flexibility and accuracy of adjusting the phase and dispersion characteristics of the subwavelength structure unit 10. In addition, since electromagnetic waves of different frequencies are subject to dispersion when incident on the array, independent phase control over a wide range can be achieved through multi-resonance, and combined with achromatic aberration and spatial phase compensation, bandwidth expansion can be achieved.

[0069] In a possible implementation, the third single resonant structure 110 includes a first patch 111 along a first direction, a second patch 112 arranged along a second direction, and a capacitor 140;

[0070] The first patch 111 and the second patch 112 are perpendicular to each other, and the capacitor 140 is disposed on the first patch 111 and / or the second patch 112 , and the capacitor 140 is located at the separation between the first patch 111 and / or the second patch 112 .

[0071] Optionally, the capacitor 140 may be an interdigital capacitor, an equivalent gap capacitor, etc. The structure of the capacitor 140 may be selected according to actual conditions.

[0072] The phase and dispersion characteristics of the subwavelength structure unit 10 in the third resonance region are determined by the capacitance value of the capacitor 140 , the size of the first patch 111 , and the size of the second patch 112 .

[0073] In one embodiment, the third resonance region may be a low frequency region.

[0074] Optionally, the capacitance value of the capacitor 140 can be 1.0 pF, 1.2 pF, 2.2 pF, etc.

[0075] As can be understood, there is a breakpoint between the first patch 111 and the second patch 112. The breakpoint divides the first patch 111 and the second patch 112 into two parts. Capacitor 140 is disposed at this breakpoint, with one end of capacitor 140 contacting a portion of the first patch 111 or the second patch 112, and the other end of capacitor 140 contacting another portion of the second patch 112 or the first patch 111. In other words, capacitor 140 connects the two parts of the first patch 111 or the second patch 112, which are divided by the breakpoint.

[0076] In a possible implementation, the first single resonant structure 120 includes a third patch 123 and a fourth patch 124 arranged along the first direction, and a fifth patch 125 and a sixth patch 126 arranged along the second direction.

[0077] Among them, the third patch 123 and the fourth patch 124 are parallel, and the fifth patch 125 and the sixth patch 126 are parallel; the first patch 111 is arranged between the fifth patch 125 and the sixth patch 126, and is perpendicular to the fifth patch 125 and the sixth patch 126; the second patch 112 is arranged between the third patch 123 and the fourth patch 124, and is perpendicular to the third patch 123 and the fourth patch 124.

[0078] In a possible implementation, the second single resonant structure 130 includes a seventh patch 137 and an eighth patch 138 arranged along the first direction, and a ninth patch 139 and a tenth patch 131 arranged along the second direction.

[0079] The seventh patch 137 and the eighth patch 138 are parallel, the ninth patch 139 and the tenth patch 131 are parallel, and the seventh patch 137 and the eighth patch 138 are perpendicular to the ninth patch 139 and the tenth patch 131 .

[0080] Here, one or more of the first patch 111, the second patch 112, the third patch 123, the fourth patch 124, the fifth patch 125, the sixth patch 126, the seventh patch 137, the eighth patch 138, the ninth patch 139 and the tenth patch 131 may be metal patches.

[0081] Optionally, the first patch 111, the fifth patch 125, and the sixth patch 126 can form an open shape such as a "工" shape, a "土" shape, or a "士" shape. The second patch 112, the third patch 123, and the fourth patch 124 can also form an open shape such as a "工" shape, a "土" shape, or a "士" shape.

[0082] The seventh patch 137, the eighth patch 138, the ninth patch 139, and the tenth patch 131 can form a closed shape such as a square or a matrix.

[0083] Exemplarily, as Figure 1 shown, Figure 1 it is shown in that the first patch 111, the fifth patch 125, and the sixth patch 126 are in the shape of a "工", the second patch 112, the third patch 123, and the fourth patch 124 are also in the shape of a "工", and the seventh patch 137, the eighth patch 138, the ninth patch 139, and the tenth patch 131 are square. Among them, the third single resonant structure 110 and the first single resonant structure 120 are orthogonally arranged, and the second single resonant structure 130 is embedded in multiple regions formed by the third single resonant structure 110 and the first single resonant structure 120.

[0084] It should be understood that for the third single resonant structure 110, the phase and dispersion characteristics can be adjusted by adjusting the capacitance value of the capacitor 140 on the third single resonant structure 110, the length of the first patch 111, and the length of the second patch 112. For the first single resonant structure 120, the phase and dispersion characteristics can be adjusted by adjusting the lengths of the third patch 123, the fourth patch 124, the fifth patch 125, and the sixth patch 126. For the second single resonant structure 130, the phase and dispersion characteristics can be adjusted by the lengths of the seventh patch 137, the eighth patch 138, the ninth patch 139, and the tenth patch 131. It should be understood that by setting the third single resonant structure 110, the first single resonant structure 120, and the second single resonant structure 130 in the sub-wavelength structure unit 10. The phase and dispersion characteristics of the third resonant region can be regulated based on the capacitance value of the third single resonant structure 110 and the side length of the third single resonant structure 110, the phase and dispersion characteristics of the first resonant region can be regulated based on the side length of the first single resonant structure 120, and the phase and dispersion characteristics of the second resonant region can be regulated based on the side length of the second single resonant structure 130, so as to independently regulate the phase and dispersion characteristics of different frequency bands.

[0085] Next, taking a specific structure of the sub-wavelength structure unit 10 as an example, the process of regulating the phase and dispersion characteristics of the sub-wavelength structure unit 10 in the embodiments of the present application is further demonstrated:

[0086] Exemplarily, taking Figure 1 、 Figure 2Taking the subwavelength structure unit 10 shown as an example, the subwavelength structure unit 10 may include a first patch 111 and a second patch 112 with a length of 2L1, a third patch 123, a fourth patch 124, a fifth patch 125, and a sixth patch 126 with a length of L2. The first patch 111, the fifth patch 125, and the sixth patch 126 form an "I"-shaped structure, the second patch 112, the third patch 123, and the fourth patch 124 form an "I"-shaped structure, and the seventh patch 137, the eighth patch 138, the ninth patch 139, and the tenth patch 131 form a square ring structure with a length of L3. The line width w of the patches in the subwavelength structure is 2 mm. The metal reflective layer 200 is a square metal patch with a side length of p. The thickness h1 of the first film 300 is 0.025 mm, and the first film 300 is a square with a side length of p. The thickness h2 of the gap layer is 9 mm. The capacitance C of capacitor 140 is 1 pF. During the control process, the phase of the subwavelength structure unit 10 can be controlled by changing the capacitance of capacitor 140 and the geometric parameters L1, L2, and L3 of the third patch 123, the fourth patch 124, the fifth patch 125, the sixth patch 126, the seventh patch 137, the eighth patch 138, the ninth patch 139, and the tenth patch 131.

[0087] Please refer to Figure 3 , Figure 3 The electromagnetic performance simulation results of the sub-wavelength structural unit 10 provided in the embodiment of the present application are shown. Figure 3 (a) Specifically shown Figure 1 、 Figure 2 The electromagnetic performance simulation results are as follows: the parameters of the subwavelength structural unit are: p = 21mm, L1 = 7.2mm, L2 = 13.8, L3 = 6mm, w = 2mm, h1 = 0.025mm, h2 = 9mm, C = 1.2pF or 15pF; Figure 3 (b) Specifically shown are the electromagnetic performance simulation results for the case where p = 21 mm, L1 = 9.3 mm, L2 = 16.5 mm, w = 2 mm, h1 = 0.025 mm, h2 = 9 mm, C = 1.2 pF, and L3 = 4.1 mm or 8.1 mm; Figure 3 (c) Specifically shown are the electromagnetic performance simulation results when p = 21 mm, L1 = 5.1 mm, L3 = 1.8, w = 2 mm, h1 = 0.025 mm, h2 = 9 mm, C = 1.2 pF, and L2 = 3.6 mm or 5.1 mm.

[0088] The simulation results show that by keeping the geometric parameters of the third patch 123, the fourth patch 124, the fifth patch 125, the sixth patch 126, the seventh patch 137, the eighth patch 138, the ninth patch 139 and the tenth patch 131 unchanged, and changing the capacitance value C of the capacitor 140, the reflection phase of the third resonant region (4.0-5.2GHz) can be regulated; by keeping the capacitance value of the capacitor 140 and the geometric parameters of the first patch 111, the second patch 112, the third patch 123, the fourth patch 124, the fifth patch 125 and the sixth patch 126 unchanged, and changing the capacitance value C of the seventh patch 137, the eighth patch 138 and the ninth patch 139 can be regulated. The outer side length L3 of the patch 138, the ninth patch 139 and the tenth patch 131 can realize the regulation of the reflection phase of the second resonance region (5.2-6.6GHz); by keeping the capacitance value of the capacitor 140 and the geometric parameters of the first patch 111, the second patch 112, the seventh patch 137, the eighth patch 138, the ninth patch 139 and the tenth patch 131 unchanged, and changing the length L2 of the third patch 123, the fourth patch 124, the fifth patch 125 and the sixth patch 126, the reflection phase of the first resonance region (6.6-8.0GHz) can be regulated, and the phase regulation in the three resonance regions is independent.

[0089] In the above implementation process, the third single resonant structure 110 includes a first patch 111, a second patch 112, and a capacitor 140; the first single resonant structure 120 includes a third patch 123, a fourth patch 124, a fifth patch 125, and a sixth patch 126; and the second single resonant structure 130 includes a seventh patch 137, an eighth patch 138, a ninth patch 139, and a tenth patch 131. That is, the third single resonant structure 110, the first single resonant structure 120, and the second single resonant structure 130 are formed by several patches and / or capacitors 140. This has a simple structure and is easy to implement, thereby simplifying the structure of the subwavelength structure unit 10.

[0090] In a possible implementation, the spacer layer is a gas layer and / or a dielectric layer; the sub-wavelength structural unit further includes: a bracket.

[0091] The surface of the first film 300 away from the sub-wavelength structure 100 and the metal reflective layer 200 are connected via a bracket.

[0092] Optionally, the gas layer is filled with gas, for example, air, inert gas, etc.

[0093] The support here refers to a structure that separates the first film 300 from the second film 400. For example, a support rod, an empty frame, etc. The support can be selected according to actual conditions.

[0094] Optionally, the spacer layer may also be a dielectric layer, and the dielectric layer may be filled with dielectric materials such as foam and honeycomb. The specific structure of the spacer layer may be adjusted according to actual conditions.

[0095] In the above implementation process, by setting the spacer layer as a gas layer and / or a dielectric layer, according to the microstrip transmission line theory, the gas layer and / or the dielectric layer are introduced into the overall structure, thereby increasing the Q value and improving the resonance bandwidth.

[0096] like Figure 4 , which is a schematic structural diagram of a reflective array, including: a plurality of sub-wavelength structural units 10 in the above embodiment arranged in an array plane arrangement manner.

[0097] The lateral arrangement interval and / or the longitudinal arrangement interval between adjacent sub-wavelength structural units 10 is less than half a wavelength.

[0098] The reflective array here can be constructed by compensating for the spatial phase shift and dispersion of the planar array through the sub-wavelength structural unit 10 and the optimization algorithm.

[0099] Optionally, the optimization algorithm may include a genetic algorithm, a particle swarm algorithm, a conjugate gradient algorithm, a neural network algorithm, etc. The optimization algorithm may be selected according to actual conditions.

[0100] The above-mentioned reflective array can be formed by arranging a plurality of sub-wavelength structural units 10. For example, 15, 10, 20, etc. The number of sub-wavelength structural units 10 in the reflective array can be selected according to actual conditions.

[0101] Optionally, the shape of the reflective array includes: circular ( Figure 4 ), square, rectangle, hexagon, etc. The shape of the reflective array can be selected according to actual conditions.

[0102] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the structure of a reflector array provided in an embodiment of the present application. The reflector array is constructed using subwavelength structural units 10 combined with an intelligent optimization algorithm to compensate for the spatial phase shift and dispersion of a planar array, resulting in an achromatic, focusing, multi-resonant subwavelength reflector array. The reflector array has 15 subwavelength structural units 10 arranged radially. The reflector array is arranged in a circular configuration.

[0103] In the above implementation process, a reflective array is constructed by arranging a plurality of sub-wavelength structural units 10 in an array plane, so that the bandwidth of the reflective array can be expanded, thereby improving the bandwidth of the reflective array.

[0104] like Figure 5 FIG. 1 is a schematic structural diagram of a broadband planar thin film antenna, comprising: a feed antenna and the reflector array in the above embodiment.

[0105] The feed antenna is arranged on one side of the reflector array.

[0106] The feed antenna here is the core component of the antenna system. As a primary radiator, its function is to efficiently convert the RF signal from the feed line into electromagnetic waves and radiate them to the reflecting surface or lens, while receiving the reflected signal and transmitting it to the receiving system.

[0107] The feed antenna is configured to transmit electromagnetic waves to the reflective array and / or receive electromagnetic waves reflected by the reflective array.

[0108] It should be understood that since the broadband planar film antenna includes a reflective array, and the reflective array includes a plurality of sub-wavelength structural units 10 arranged in an array surface arrangement, the bandwidth of the broadband planar film antenna can be expanded.

[0109] The following are several experimental test results to verify the commonality of the broadband planar film antenna in the embodiment of the present application:

[0110] Please refer to Figure 6 , Figure 6 The experimental test results of the directional pattern of a broadband planar thin film antenna provided in an embodiment of the present application are shown. Figure 6 (a)-(d) are the normalized radiation patterns of simulation and test at some frequency points, where the solid line is the simulation result and the dotted line is the test result. It can be seen that the simulation results are consistent with the experimental test results and have lower sidelobes.

[0111] Please refer to Figure 7 , Figure 7 The simulation and test results show that the broadband planar thin film antenna has good high gain characteristics in a broadband range.

[0112] In the above implementation process, by setting the broadband planar film antenna to include a reflective array, and the reflective array includes multiple sub-wavelength structural units 10 arranged according to the array surface arrangement, the bandwidth of the broadband planar film antenna can be expanded and the bandwidth of the broadband planar film antenna can be increased.

[0113] In a possible implementation, the feed antenna includes one of a patch antenna, a standard waveguide, a slot antenna, and a Vivaldi antenna.

[0114] Among them, the patch antenna is a planar antenna designed based on microstrip line technology, which has the advantages of being light, thin, low-profile, and easy to integrate.

[0115] A standard waveguide is a metal tubular structure used for efficient microwave signal transmission. Its cross-sectional shape and dimensions adhere to international or industry standards. By confining electromagnetic waves to propagate in a specific pattern within the tube, a standard waveguide achieves low-loss, high-power signal transmission.

[0116] A slot antenna is an antenna with a slot structure on a metal surface. It transmits and receives signals through electromagnetic radiation from the slot. It has the advantages of flexible structure and easy integration.

[0117] The Vivaldi antenna is an ultra-wideband (UWB) end-fire traveling-wave antenna with many advantages, such as simple structure, easy manufacturing, high gain and wide bandwidth.

[0118] It should be understood that the feed antenna in the embodiments of the present application is not limited to the antennas listed in the above embodiments. The feed antenna can also be other types of antennas, and this application does not impose specific restrictions.

[0119] In the above implementation process, by setting the feed antenna to include one of the patch antenna, standard waveguide, slot antenna, and Vivaldi antenna, the corresponding feed antenna can be selected according to actual needs, thereby increasing the flexibility of feed antenna selection and increasing the application scenarios of the broadband planar thin film antenna.

[0120] See also Figure 8 , is a flow chart of the method for preparing a sub-wavelength structural unit provided in the embodiment of the present application. Figure 8 The specific process shown is explained in detail.

[0121] Step S201 : determining first set parameters of a target single resonant structure and / or second set parameters of a target capacitance of each resonant region according to an operating frequency of each resonant region of a sub-wavelength structure unit and a set resonance formula.

[0122] The first setting parameter here may include shape and / or setting size, such as length, width, thickness, etc.

[0123] The above-mentioned formula for setting resonance may be a set calculation formula or a characteristic algorithm model, etc. The formula for setting resonance may be selected according to actual conditions.

[0124] Optionally, in different application scenarios, the corresponding setting resonance formula may be different.

[0125] The second setting parameter here may include a capacitance value.

[0126] The target single resonant structure mentioned above refers to a single resonant structure in a target sub-wavelength structure unit.

[0127] Step S202 : preparing a target single resonant structure on a first film according to first set parameters.

[0128] Wherein, when preparing the target single resonant structure on the first film, the preparation can be performed according to the determined shape and size of the target single resonant structure.

[0129] Step S203: separate one or more regions in one or more target single resonant structures.

[0130] The target single resonant structure here includes one or more patches, breakpoints are set on the one or more patches in the target single resonant structure, and the corresponding one or more patches are disconnected at the breakpoints.

[0131] The breakpoint is used to prepare the target capacitance.

[0132] Step S204 : setting a target capacitance on a side away from the first film at a separation point of one or more target single resonant structures according to a second set parameter.

[0133] When preparing the target capacitor, the target capacitor may be prepared according to the determined shape and capacitance value.

[0134] The target capacitor is set at the breakpoint of the target single resonant structure, with one end of the target capacitor contacting one part of the disconnected patch and the other end of the target capacitor contacting the other part of the disconnected patch. In other words, the target capacitor connects the two parts of the patch divided by the breakpoint.

[0135] Step S205: preparing a metal reflective layer on the second film.

[0136] Step S206 , disposing a first film and a second film on opposite sides of the spacer layer.

[0137] In another embodiment, Figure 9 As shown, the method for preparing the sub-wavelength structural unit may further include the following steps:

[0138] Step S301 : determining first setting parameters of a target single resonance structure of each resonance region according to an operating frequency of each resonance region of a sub-wavelength structure unit and a setting resonance formula.

[0139] Step S302 : preparing a target single resonant structure on a first film according to first set parameters.

[0140] Step S303: preparing a metal reflective layer on the second film.

[0141] Step S304 : placing a first film and a second film on opposite sides of the spacer layer.

[0142] The foregoing description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures.

[0143] 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 the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A sub-wavelength structural unit, characterized in that: include: A subwavelength structure, a metal reflective layer, a first film, and a second film; wherein the subwavelength structure includes: at least two types of single resonant structures; At least two types of the single resonant structures are both arranged on the first film; The metal reflective layer is provided on the second film; A spacer layer is provided between the first film and the second film; The phase and dispersion characteristics of the sub-wavelength structure unit in the first resonance region and / or the second resonance region are determined by setting parameters of the single resonance structure.

2. The sub-wavelength structural unit according to claim 1, characterized in that: The single resonant structures are of three types, including: a first single resonant structure, a second single resonant structure and a third single resonant structure; The phase and dispersion characteristics of the subwavelength structure unit in the first resonance region are determined by the size of the first single resonance structure; the phase and dispersion characteristics of the subwavelength structure unit in the second resonance region are determined by the size of the second single resonance structure; and the phase and dispersion characteristics of the subwavelength structure unit in the third resonance region are determined by the capacitance value and size of the third single resonance structure.

3. The sub-wavelength structural unit according to claim 2, characterized in that: The third single resonant structure includes a first patch along the first direction, a second patch arranged along the second direction, and a capacitor; Wherein, the first patch and the second patch are perpendicular; The capacitor is provided on the first patch and / or the second patch, and the capacitor is located at a separation between the first patch and / or the second patch; The phase and dispersion characteristics of the subwavelength structure unit in the third resonance region are determined by the capacitance value of the capacitor, the size of the first patch, and the size of the second patch.

4. The sub-wavelength structural unit according to claim 3, characterized in that: The first single resonant structure includes a third patch and a fourth patch arranged along the first direction, and a fifth patch and a sixth patch arranged along the second direction; Among them, the third patch is parallel to the fourth patch, and the fifth patch is parallel to the sixth patch; the first patch is arranged between the fifth patch and the sixth patch, and is perpendicular to the fifth patch and the sixth patch; the second patch is arranged between the third patch and the fourth patch, and is perpendicular to the third patch and the fourth patch.

5. The sub-wavelength structural unit according to claim 2, characterized in that: The second single resonant structure includes a seventh patch and an eighth patch arranged along the first direction, and a ninth patch and a tenth patch arranged along the second direction; The seventh patch is parallel to the eighth patch, the ninth patch is parallel to the tenth patch, and the seventh patch and the eighth patch are perpendicular to the ninth patch and the tenth patch.

6. The sub-wavelength structural unit according to any one of claims 1 to 5, characterized in that: The spacer layer is a gas layer and / or a dielectric layer; the sub-wavelength structural unit further includes: a bracket; A side of the first film away from the sub-wavelength structure and the metal reflective layer are connected via the bracket.

7. A reflective array, characterized in that: include: A plurality of sub-wavelength structural units according to any one of claims 1 to 6 arranged in an array arrangement; Wherein, the lateral arrangement interval and / or the longitudinal arrangement interval between adjacent sub-wavelength structural units is less than half a wavelength.

8. A broadband planar film antenna, characterized in that: include: A feed antenna and a reflector array according to claim 7; The feed antenna is arranged on one side of the reflector array; The feed antenna is configured to transmit electromagnetic waves to the reflector array and / or receive the electromagnetic waves reflected by the reflector array.

9. The broadband planar film antenna according to claim 8, characterized in that: in, The feed antenna includes one of a patch antenna, a standard waveguide, a slot antenna and a Vivaldi antenna.

10. A method for preparing a sub-wavelength structural unit, characterized in that: The method comprises: Determine a first set parameter of a target single resonance structure and a second set parameter of a target capacitance of each resonance region according to the operating frequency of each resonance region of the subwavelength structure unit and a set resonance formula; preparing the target single resonant structure on the first film according to the first set parameters; separating one or more regions in one or more of the target single resonant structures; Setting the target capacitance on a side away from the first film at a separation point of one or more target single resonant structures according to the second setting parameter; preparing a metal reflective layer on the second film; placing the first film and the second film on opposite sides of the spacer layer; or, Determine first set parameters of the target single resonance structure of each resonance region according to the operating frequency of each resonance region of the sub-wavelength structure unit and the set resonance formula; preparing the target single resonant structure on the first film according to the first set parameters; preparing a metal reflective layer on the second film; The first film and the second film are disposed on opposite sides of the spacer layer.

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