Reflective array

Abstract

The purpose of the present invention is to provide a reflective array which is reduced in thickness and weight. A representative reflective array of the present invention is a reflective array including a ground layer, a dielectric layer, and an element pattern layer having a plurality of element patterns, the reflective array being characterized in that the thickness t (mm), which is the thickness of the dielectric layer, and the element length l (mm), which is the length of the plurality of element patterns, satisfy the following relational expression. In addition, the surface resistance value of the grounding layer is less than or equal to 100 omega / square. In addition, at least one of the ground layer and the element pattern layer is formed of Cu or Al.

Description

TECHNICAL FIELD

[0001] The present application relates to a reflecting array capable of reflecting electromagnetic waves of specific frequencies. BACKGROUND

[0002] With respect to the 5th generation mobile communication system (5G), electromagnetic waves of sub 6 frequency band (3.6 GHz~) higher than the existing LTE (4G) and millimeter wave frequency band (24 GHz~) are used. The millimeter wave has the following characteristics, that is, the information capacity is large, and on the contrary, the straight propagation property of the electromagnetic wave is high, and the reaching distance is short. Therefore, in the case of using electromagnetic waves of the millimeter wave frequency band, there is a problem that the electromagnetic wave is sharply attenuated due to the shielding of buildings and the like, and a "communication blind area" in which the communication quality cannot be ensured is easily generated. This problem can be solved by adding a base station or a repeater, but there are various obstacles such as cost, securing of the place of installation, and the like.

[0003] The reflecting array is a reflecting plate capable of asymmetrically reflecting electromagnetic waves of specific frequencies by its special configuration. Unlike a metal reflecting plate that reflects electromagnetic waves in a positive direction like a mirror, the frequency band, the incident direction and the reflection direction, or the diffusion method of the reflected wave can be freely designed to be reflected. By utilizing such characteristics, it is expected that the electromagnetic wave condition can be improved without adding a base station to the communication blind area.

[0004] Based on the above background, the development of the reflecting array is thriving.

[0005] In Patent Literature 1, it is disclosed that a reflecting array that reflects an incident wave toward a desired direction includes a substrate having a surface perpendicular to a prescribed axis, and a plurality of elements provided to the substrate, a specific element of the plurality of elements reflecting the incident wave with a specific reflection phase of a plurality of reflection phases, the plurality of elements each having an element configuration having at least a patch and a ground plate, an element interval of a first adjacent element being different from an element interval of a second adjacent element, and a length of a gap between the patches of the first adjacent element being equal to a length of a gap between the patches of the second adjacent element.

[0006] In Patent Literature 2, a relay device has a periodic array in which metal-made phase shift elements are alternately arranged, the array being periodic in at least one axis, formed on a first surface of a dielectric substrate, the surface opposite to the first surface of the dielectric substrate having a ground plane formed thereon, each phase shift element providing a phase shift of 0° to 360° in a microwave frequency range. It is disclosed that the relay device can be used in a microwave network.

[0007] In Patent Literature 3, it is disclosed that a metasurface reflection plate has a dielectric substrate, a metal ground layer provided on a bottom surface of the dielectric substrate, which makes all directions of polarized waves not pass through the metasurface reflection plate, and a plurality of super units having two or more cross-shaped metal resonators different in arm length. The super units having the metal resonators are formed on an upper surface of the dielectric substrate, arranged at a period of a diffraction grating, which reflects vertical and horizontal polarized waves of incident waves and makes electromagnetic waves at a prescribed frequency reflect at a required phase.

[0008] Patent Literature 1: Japanese Patent No. 5410558

[0009] Patent Literature 2: Japanese Patent No. 7026124

[0010] Patent Literature 3: Japanese Patent Application Publication No. 2021-048465 SUMMARY

[0011] The thinning and lightening of the reflection array have many advantages in terms of manufacturing and construction, but have not been sufficiently studied in any of the prior arts.

[0012] Therefore, an object of the present application is to provide a reflection array that achieves thinning and lightening.

[0013] To solve the above problems, one of the representative reflection arrays of the present application is characterized by including a ground layer, a dielectric layer, and an element pattern layer having a plurality of element patterns, the thickness t (mm) of the dielectric layer and the length l (mm) of the plurality of element patterns satisfy the following relationship:

[0014] [Formula 1]

[0015] l ≥ 4.4 x t and 0.001 < t < 0.25.

[0016] EFFECT OF THE INVENTION

[0017] According to the present application, a reflection array that achieves thinning and lightening can be provided.

[0018] The above-mentioned problems, structures, and effects other than the above are made clear by the description of the means for carrying out the following invention. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a cross-sectional view of a reflection array related to the first embodiment.

[0020] Figure 2 is a view schematically showing a part of the reflection array.

[0021] Figure 3 This is a diagram showing a cross-shaped element pattern.

[0022] Figure 4 This is a diagram showing an example of the result of a simulation on the reflection control area.

[0023] Figure 5 It is a cross-sectional view of a reflect array according to a modified example of the first embodiment.

[0024] Figure 6 It is a cross-sectional view of a reflect array according to the second embodiment.

[0025] Figure 7 It is a cross-sectional view of a reflect array according to the second embodiment.

[0026] Figure 8 It is a cross-sectional view of a reflect array according to the third embodiment.

[0027] Figure 9 It is a cross-sectional view of a reflect array according to the third embodiment.

[0028] Figure 10 It is a cross-sectional view of a reflect array according to the third embodiment.

[0029] Figure 11 It is a cross-sectional view of a reflect array according to the third embodiment.

[0030] Figure 12 It is a cross-sectional view of a reflect array according to the third embodiment.

[0031] Figure 13 It is a cross-sectional view of a reflect array according to the third embodiment.

[0032] Figure 14 It is a cross-sectional view of a reflect array according to the third embodiment.

[0033] Figure 15 This is a diagram showing the evaluation results of whether the reflection control region can obtain the desired reflection phase characteristics through simulation.

[0034] Figure 16 This is a diagram showing evaluation results when a reflect array is produced.

[0035] Figure 17 It is a diagram showing the shape of the element pattern.

[0036] Figure 18 It is a diagram showing the shape of the element pattern. DETAILED DESCRIPTION

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to these embodiments. In the description of the accompanying drawings, the same reference numerals are used to indicate the same parts.

[0038] In addition, when there are multiple components having the same or the same function, different superscripts may be assigned to the same reference numerals for description. In addition, when there is no need to distinguish the multiple components, superscripts may be omitted for description.

[0039] In the present invention, "surface" refers not only to the surface of a plate-like component but also, in some cases, to the interface between layers contained in a plate-like component and substantially parallel to the surface of the plate-like component. Furthermore, "upper surface" and "lower surface" refer to the surface shown above or below in a drawing when illustrating a plate-like component or a layer contained in a plate-like component. Furthermore, "upper surface" and "lower surface" may also be referred to as "first surface" and "second surface."

[0040] In addition, the distance in the z-axis direction is sometimes referred to as "thickness".

[0041] In addition, a “cross-sectional view” may refer to a part or all of a cross section of an object.

[0042] Furthermore, "obtaining a desired reflection phase characteristic" refers to having characteristics that produce multiple targeted reflection phases. For example, if the difference between the upper and lower limits of the reflection phase can be set to a desired phase difference when a certain parameter is varied within a predetermined range, or if multiple targeted reflection phases can be obtained when a certain parameter is varied within a predetermined range, then "the desired reflection phase characteristic" can be said to be obtained.

[0043] [First embodiment]

[0044] Figure 1 This is a cross-sectional view of a reflectarray 1 according to the first embodiment. The reflectarray 1 includes a ground layer 11, a dielectric layer 12, and an element pattern layer 13. The element pattern layer 13 is a layer having a plurality of element patterns 14. As described later, the thickness tp of the element pattern layer 13 is, for example, greater than or equal to 10 nm and less than or equal to 18 μm.

[0045] (Ground layer)

[0046] The ground layer 11 is provided to reflect electromagnetic waves reaching the reflect array 1. It also supports and protects the dielectric layer 12 described later. The ground layer 11 is made of a conductive material such as an inorganic oxide material, a metal material, or a conductive organic material.

[0047] For example, as inorganic oxide materials and metal materials, indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), antimony tin oxide, Ag, Al, Au, Pt, Pd, Cu, Co, Cr, In, Ag-Cu, Cu-Au and Ni are used. In addition, nanoparticles or nanowires containing at least one of the above materials can also be used. As conductive organic materials, polythiophene derivatives, polyacetylene derivatives, polyaniline derivatives, polypyrrole derivatives, carbon nanotubes, graphene and the like can be cited. In particular, from the perspectives of material cost, conductivity and film forming properties, Cu and Al are preferred. In addition, in order to reflect electromagnetic waves, the surface resistance value of the ground layer 11 is preferably less than or equal to 100Ω / □ (ohm per square). As long as this condition is met, inorganic oxide materials such as ITO and organic materials such as a mixture of polyethylene dioxythiophene (PEDOT) and polystyrene sulfonic acid (PSS) (PEDOT / PSS) can also be used. By using inorganic oxide materials or organic materials, a reflective array having transparency can also be produced.

[0048] Examples of forms of using the above-mentioned materials include a continuous film, a mesh shape, a perforated shape, and a periodic structure.

[0049] Here, the grid refers to a state in which mesh-like through-holes (openings) are formed on the plane of the conductor. When the conductor is formed in a grid shape, the mesh of the grid can be square or rhombus. When the mesh of the grid is formed in a square shape, the mesh of the preferred grid is square. If the mesh of the grid is square, the appearance is good. In addition, it can also be a random shape formed based on a self-assembly method. By being set to a random shape, moire fringes can be prevented. When metal is processed into a grid shape, methods such as perforation processing of a metal plate, etching of a metal plate, etc. can be adopted.

[0050] When the ground layer is in a grid shape and a transparent conductive material is used, the reflective array shows visible light transparency, and the landscape after installation can be ensured.

[0051] When the ground layer 11 is formed in a grid shape, the line width of the grid is preferably greater than or equal to 5 μm and less than or equal to 30 μm, more preferably greater than or equal to 6 μm and less than or equal to 15 μm. The line spacing of the grid is preferably greater than or equal to 50 μm and less than or equal to 500 μm, more preferably greater than or equal to 100 μm and less than or equal to 300 μm. In addition, regarding the line spacing of the grid, when the wavelength of the operating frequency (hereinafter also referred to as the "design frequency") is set to λ0 (mm), it is preferably less than or equal to 0.5×λ0, more preferably less than or equal to 0.1×λ0, and even more preferably less than or equal to 0.01×λ0. If the line spacing of the grid is less than or equal to 0.5×λ0, the performance of the ground layer 11 can be exerted. In addition, the line spacing of the grid can be greater than or equal to 0.001×λ0.

[0052] When using an inorganic oxide material or a metal material for the ground layer 11, the thickness of the ground layer 11 is preferably less than or equal to 18 μm, and more preferably within the range of greater than or equal to 50 nm and less than or equal to 2 μm. A film thickness of 50 nm or greater facilitates the formation of a uniform film without pinholes, further enhancing the function of the ground layer 11. On the other hand, a film thickness of 2 μm or less maintains sufficient flexibility, suppressing cracks in the ground layer 11 caused by external factors such as bending and stretching. By making the ground layer 11 less than or equal to 1 μm, the flexibility is increased, making it easier to attach to curved surfaces, etc., and also achieving weight reduction.

[0053] As a method for forming the ground layer 11, when a metal material is used, dry coating such as sputtering and vapor deposition, wet coating such as gravure coating or die coating by ink-forming the metal material, and surface treatment such as electroplating can be selected. Alternatively, a ground layer obtained by rolling a metal plate can be used as the ground layer 11. When an inorganic oxide material is used, dry coating can be selected as the method for forming the ground layer 11. When an organic material is used, wet coating can be selected as the method for forming the ground layer 11. Alternatively, the ground layer 11 can be formed by painting or spraying.

[0054] When the ground layer is a thin film formed by electroplating, vapor deposition, or the like, the flexibility of the reflect array can be improved, thereby enabling application to curved surfaces and roll-to-roll production processes.

[0055] Furthermore, in order to improve the reflection efficiency of electromagnetic waves, it is recommended to reduce the loss caused by the ground layer. Therefore, it is preferable that the surface roughness of the ground layer is small.

[0056] When the ground layer has a periodic structure, it can selectively reflect or transmit specific frequencies. For example, when a structure with a periodically arranged patch-like conductive pattern is used as the ground layer, it is possible to reflect only specific frequencies, thereby providing the ability to transmit frequencies other than the operating frequency. Furthermore, when a structure is used that periodically arranges areas without conductive material as holes, it is possible to design a reflective array that asymmetrically reflects the operating frequency while transmitting only specific frequencies.

[0057] In the present invention, surface resistance is measured in accordance with JIS-K-7194. As a surface resistance measurement method, a four-terminal method, a two-terminal method, a four-probe method, a dielectric method, an eddy current method, or the like can be appropriately selected. For example, the surface resistance value of the ground layer 11 can be measured using Loresta-GP MCP-T610 (trade name, manufactured by Mitsubishi Chemical Analytical Technology Co., Ltd.).

[0058] (Dielectric layer)

[0059] exist Figure 1 In the embodiment of the present invention, the thickness of the dielectric layer 12 is set to t. As the dielectric layer 12, the following materials can be used as resin components: ethylene-vinyl acetate copolymer (EVA), polyvinyl chloride, polyurethane, acrylic acid, acrylic polyurethane, polyolefin, polyethylene, polypropylene, silicone, polyethylene terephthalate, polyester, polystyrene, polyimide, polycarbonate, polyamide, polysulfone, polyethersulfone, polytetrafluoroethylene, cycloolefin polymer, epoxy resin and other synthetic resins; and synthetic rubber materials such as polyisoprene rubber, styrene-butadiene rubber, polybutadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber butadiene rubber, butyl rubber, acrylic rubber, ethylene-propylene rubber and silicone rubber. In addition, materials obtained by impregnating these resin components into glass fiber, synthetic fiber, non-woven fabric or paper can also be used. In particular, from the perspective of low price and excellent versatility, polyethylene terephthalate (PET) is preferably used. In addition, these resin materials and synthetic rubber materials can be used alone or in combination of two or more. The dielectric layer 12 may be a single layer or multiple layers. A foam obtained by foaming the above-mentioned materials may be used as the dielectric layer 12. As the foam, a highly flexible foam is preferably used.

[0060] The relative dielectric constant of the dielectric layer 12 is preferably in the range of greater than or equal to 1 and less than or equal to 20, more preferably in the range of greater than or equal to 1 and less than or equal to 10, and even more preferably in the range of greater than or equal to 2 and less than or equal to 4. If the relative dielectric constant is within this range, it is likely that the desired reflection phase characteristics will be easily obtained in the reflect array 1. In addition, the dielectric loss tangent is preferably in the range of greater than or equal to 0.00005 and less than or equal to 0.01, more preferably in the range of greater than or equal to 0.00005 and less than or equal to 0.001. If it is within this range, a reflect array 1 with low dielectric loss can be produced.

[0061] The dielectric layer 12 can be formed using, for example, wet coating methods such as die coating, comma coating, and gravure coating, melt extrusion methods such as T-die method and inflation method, calendaring film forming method, solution casting method, hot pressing method, etc. In addition, a co-extrusion method can be used to extrude multiple resins in layers to form a thin film.

[0062] The thickness t of the dielectric layer 12 is appropriately selected according to the design frequency. When the design frequency is set to 28 GHz, it is preferably greater than or equal to 40 μm and less than or equal to 250 μm, and more preferably greater than or equal to 50 μm and less than or equal to 200 μm. If it is too thin, it is difficult to ensure the reflection phase and it is difficult to design the reflect array 1. On the other hand, if it is too thick, it tends to be difficult to ensure the reflection phase, the flexibility disappears, and the total thickness of the reflect array 1 becomes thicker, making it difficult to achieve space saving. Therefore, the thickness t of the dielectric layer 12 is preferably less than or equal to 250 μm. When the design frequency is set to 60 GHz, the thickness t of the dielectric layer 12 is preferably greater than or equal to 10 μm and less than or equal to 250 μm. When the design frequency is greater than or equal to 100 GHz, if the thickness t of the dielectric layer 12 is set to greater than or equal to a few μm and less than or equal to about 100 μm, it is easy to design the reflect array 1. Even when the thickness t of the dielectric layer 12 is set to be less than or equal to 250 μm, a sufficient reflection phase may not be ensured due to the relationship with the element length l of the element pattern 14 described later. The reflect array 1 can be manufactured by satisfying both the relationship between the element length l and the thickness t of the dielectric layer 12 in equations (6) and (7) described later, and the relationship between the thickness t of the dielectric layer 12. If the thickness t of the dielectric layer 12 is less than or equal to 1 μm, it tends to be difficult to stably form the dielectric layer 12 using the above-mentioned formation method.

[0063] In addition to the above materials, dielectric layer 12 can be formed from a material comprising a metal compound contained within a resin component. The density and dielectric constant of dielectric layer 12 can be adjusted by the type and content of the metal compound in dielectric layer 12. The inclusion of a metal compound in dielectric layer 12 can enhance flame retardancy and provide a flame spread prevention effect. Examples of the metal compound include barium titanate, titanium dioxide, and zinc oxide. The metal compound is preferably in the form of a powder (e.g., nanoparticles).

[0064] The thickness t of the dielectric layer 12 can be measured using a micrometer method (JIS-C-2151). Alternatively, a spectral interferometry film thickness gauge, an electromagnetic film thickness gauge, an eddy current film thickness gauge, an infrared film thickness gauge, an ultrasonic film thickness gauge, or ellipsometry can be used as a thickness measurement method. Alternatively, a microscope-based film thickness measurement method can be used, such as a microscopic photography method, a field micrometer method, an eyepiece micrometer method, or a scanning electron microscope method.

[0065] (Component pattern layer)

[0066] The element pattern layer 13 is provided to asymmetrically reflect incident electromagnetic waves, reflecting them in a direction different from the symmetrical reflection. The thickness tp of the element pattern layer 13 is, for example, greater than or equal to 10 nm and less than or equal to 18 μm. Considering flexibility and film-forming properties, a thinner thickness is preferred as long as it does not affect the asymmetrical reflection function.

[0067] The element pattern layer 13 preferably has a surface resistance of 100 Ω / □ or less. The material used for the element pattern layer 13 is, for example, a conductive material. The same material as that used for the ground layer 11 can be used as a related material. A conductive inorganic material or organic material can be formed into a film on the dielectric layer 12. From the perspectives of flexibility, film forming properties, stability, sheet resistance, and low cost, a thin film formed by vapor deposition, as described later in the formation method, is preferably used as the element pattern layer 13.

[0068] Examples of forms using the above-mentioned materials include a continuous film, a mesh shape, and a perforated shape.

[0069] As a method for forming the element pattern layer 13, a method of forming a conductive material on the entire surface of the dielectric layer 12 to obtain a continuous film and then forming the element pattern layer 13 by processing can be adopted, or a method of directly forming the element pattern layer 13 on the dielectric layer 12 can be adopted.

[0070] As a method of forming a continuous film of a material having electrical conductivity over the dielectric layer 12, if it is a metal, it can be selected from dry coating such as sputtering method, evaporation method, plating treatment, gravure coating using a metal ink, die coating, and the like, wet coating, and the like. Alternatively, a structure obtained by calendering a metal plate can be attached to the dielectric layer 12. Similarly, if it is an inorganic oxide material, a continuous film can be formed by dry coating, and if it is an organic material, a continuous film can be formed by wet coating. In addition, painting, spraying method can be used.

[0071] For the formed continuous film, an unnecessary portion is removed by removal processing using dry etching, wet etching, cutting, and the like, thereby forming the element pattern layer 13.

[0072] In a case where removal processing is performed by an etching method, it is possible that R is formed at the end portion of the element pattern 14 constituting the reflection array 1 (in other words, formed in a state of having a circular arc), or a pinhole is generated, a cross-sectional shape becomes a right conical shape, an inverted conical shape, or the like, or under cut or over etching occurs. It is conceivable that such a shape change occurs by etching processing, but if the direction of the main beam in the reflected electromagnetic wave is within a range of about ±5° of the designed reflection angle, it is allowable as a reflection phase characteristic. In a case where it is formed by cutting, printing method, dry coating, plating treatment, painting, spraying method, it is also similarly allowable.

[0073] In a case where an etching method is used, Figure 1 The cross-sectional shape of the element pattern 14 shown is preferably a shape in which the bottom expands in the -Z axis direction, that is, a right conical shape. Since it is a right conical shape, the surface area of the element pattern 14 increases, and it is possible to increase the adhesion to a functional layer when the functional layer described later is laminated.

[0074] Further, as a method of directly forming the element pattern layer 13 over the dielectric layer 12, a method of printing by using a letterpress printing, a lithographic printing, a gravure printing, a hole printing, a transfer printing, and the like, performing mask treatment of a portion other than the element pattern 14 portion over the dielectric layer 12 using a mask tape, a mask agent, and the like, and forming the element pattern layer 13 by dry coating, plating treatment, painting, spraying method can also be used.

[0075] Regarding the material of the element pattern layer 13, the same material as that of the ground layer 11 can be used, or a different material can be used. In addition, for example, at least one layer of the ground layer 11 or the element pattern layer 13 can be formed by Cu or Al. Cu has excellent conductivity and can therefore reduce conductor loss. Al is lightweight due to its low density and low cost, so a lightweight and inexpensive reflective array 1 can be formed. In addition, the thickness of at least one layer can be set to be less than or equal to 1 μm. By setting it to be less than or equal to 1 μm, flexibility can be improved, and it can be easily set on a curved surface of the reflective array 1, etc., and lightweighting can be achieved.

[0076] When the element pattern is in a grid shape, the line width of the grid is preferably greater than or equal to 5 μm and less than or equal to 30 μm, more preferably greater than or equal to 6 μm and less than or equal to 15 μm. The line spacing of the grid is preferably greater than or equal to 50 μm and less than or equal to 500 μm, more preferably greater than or equal to 100 μm and less than or equal to 300 μm. In addition, when the wavelength at the operating frequency is set to λ0, the line spacing of the grid is preferably less than or equal to 0.5×λ0, more preferably less than or equal to 0.1×λ0, and further preferably less than or equal to 0.01×λ0. If the line spacing of the grid is less than or equal to 0.5×λ0, performance can be ensured. In addition, the line spacing of the grid can be greater than or equal to 0.001×λ0.

[0077] When the element pattern is in a grid shape and a transparent conductive material is used, the reflective array shows visible light transparency, and can ensure the appearance after installation.

[0078] When the element pattern is in the form of a thin film, the flexibility of the reflective array can be improved, thereby enabling use on a curved surface and implementing a roll-to-roll production process.

[0079] Furthermore, in order to improve the reflection efficiency of electromagnetic waves, it is possible to reduce the loss caused by the element pattern. Therefore, it is preferable that the surface roughness of the element pattern is small.

[0080] (Design Method)

[0081] Figure 2 It is a diagram schematically showing a part of the reflect array 1 . Figure 2 denoted by . The reflection control region 10 is a unit of region capable of achieving asymmetric reflection. The reflect array 1 includes a plurality of reflection control regions 10 in the xy plane. The element pattern layer 13 includes a plurality of element patterns 14a to 14d.

[0082] The design of the reflectarray 1 is carried out according to the following process. First, the length L of the long side of the reflection control region 10 is determined using the following equation (1). Here, L is the length of the long side of the reflection control region, λ0 is the wavelength of the electromagnetic wave applied to the reflectarray 1 (hereinafter also referred to as the "wavelength at the operating (design) frequency"), θi is the incident angle, and θr is the reflection angle. Incident angle θi and reflection angle θr are values ​​measured in the zx plane.

[0083] Next, the length L of the long side of the reflection control region 10 is divided into n parts (L / n), which is a unit that can accommodate one element pattern and is defined as a unit cell. The area of ​​the unit cell is a square with one side having the unit cell size (L / n). Figure 2 In FIG, the long side of the reflection control region 10 is divided into four parts, including unit cells UCa to UCd. Unit cell UCa includes an element pattern 14a. Unit cell UCb includes an element pattern 14b. Unit cell UCc includes an element pattern 14c. Unit cell UCd includes an element pattern 14d.

[0084] Next, the reflection phase required in each reflection control area is calculated by the following formula (2). Here, Zs(x) is a function of the surface impedance in the x-direction in the xy plane of the reflection control area 10, which shows the case of achieving lossless reflection. In addition, 120π is the impedance of the incident wave. The formula for the surface impedance is as shown in the following formula (3). Here, Φr(x) represents the phase of the reflection coefficient, that is, the reflection phase, as shown in the following formula (4). The element shape is determined for each position of the unit in a manner that satisfies the reflection phase (deviation angle of R) shown by formula (5) according to each formula. That is, if the incident angle θi, the reflection angle θr, and the wavelength λ0 of the electromagnetic wave are determined, the value of the reflection phase at the coordinate in the long side direction of the reflection control area 10 can be calculated.

[0085] [Formula 2]

[0086]

[0087] φ=arg R…(5)

[0088]

[0089] (Design methods related to device patterns)

[0090] After the reflection phase is determined using the above method, the shape of the element pattern 14 is varied to satisfy the reflection phase of each unit cell, and simulation is performed to optimize the shape of the element pattern 14. When electromagnetic waves are incident on the element pattern, the relationship between the shape of the element pattern 14 and the reflection phase can be determined by simulation using, for example, an electromagnetic analysis tool (High Frequency Structure Simulator: HFSS). Examples of element pattern shapes include a cross-patch (cross-shaped) structure (element patterns 14a and 14c) and a square structure (element patterns 14b and 14d).

[0091] A case where the element pattern 14 is a cross patch will be described. Figure 3 : is a diagram showing an element pattern 14 of a cross patch. A cross patch refers to a shape in which two square patches are orthogonal to each other in the xy plane. The element pattern 14 is one of the multiple element patterns possessed by the element pattern layer 13. The length of the element pattern 14 of the cross patch is set to the element length l, and the width of the element pattern 14 of the cross patch is set to the element width w. The reflection phase of the unit cell UC is controlled by changing either or both of the element length l and the element width w. When the element length l is fixed, it is preferred to set the value of the element length l as large as possible within the unit cell UC. By setting it larger, the desired reflection phase characteristics are easily obtained. In addition, when the element width w is fixed, it is preferred to set the value of the element width w as large as possible within the unit cell UC. By setting the value of the element width w to be larger, the slope of the reflection phase becomes gentle, thereby improving the processing accuracy during processing. In addition, the element length l is not limited to the element pattern set to a cross patch, and can also be set to an element pattern having other shapes. The element length l may be set to a common length in the reflection control region 10 , or may be set to a different length for each element pattern included in the reflection control region 10 .

[0092] (Design methods related to dielectric layers)

[0093] Based on the above design, the relationship between the thickness t (mm) of the dielectric layer 12 and the element length l (mm) was also studied. As a result, it was found that the desired reflection phase characteristics can be obtained when the relationship of the following formula (6) is satisfied. By satisfying formula (6), a thin-film reflective array 1 can be obtained. Here, it can be seen that when l ≥ 4.4 × t, the desired reflection phase can be obtained. On the other hand, if l < 4.4 × t, a good reflection phase cannot be obtained. In addition, it can be seen that if the thickness t of the dielectric layer 12 is greater than 0.25 mm, it is difficult to produce a flexible reflective array 1. In addition, if the thickness t of the dielectric layer 12 is less than 0.001 mm, it is difficult to form the dielectric layer 12.

[0094] [Formula 3]

[0095] l≥4.4×t and 0.001 <t<0.25...(6)

[0096] Furthermore, the relationship between the operating frequency (wavelength λ0 (mm) at the operating frequency) and the thickness t (mm) of the dielectric layer 12 was also studied. It was found that the desired reflection phase characteristics can be obtained when the relationship shown in the following equation (7) is satisfied. It can be seen that satisfying equation (7) allows the desired reflection phase to be obtained, while not satisfying equation (7) does not result in a satisfactory reflection phase.

[0097] [Formula 4]

[0098] 0.001 <t<0.065×λ0...(7)

[0099] (Example of reflection phase)

[0100] Reference Figure 4 The properties of the reflection phase are described. Figure 4 This is a diagram showing an example of the result of a simulation performed on a unit cell.

[0101] When using the electromagnetic field analysis tool HFSS to simulate the reflection phase while keeping the element length l constant and varying the element width w, phase variations such as those shown in curves A to C can generally be detected. Curves A to C share the same structure of the ground layer 11, dielectric layer 12, and element pattern layer 13, but the thickness t of the dielectric layer 12 is set to 40 μm in Curve A, 200 μm in Curve B, and 800 μm in Curve C. The element length l is 3.00 mm. For example, if the three points indicated by the dashed lines, 150°, 50°, and -100°, are to be included in the reflection phase range, all three points can be included in Curve B. Thus, for the reflection phase characteristics of Curve B, by varying the element width w within a specified range, the difference between the upper and lower limits of the reflection phase can be set to the desired phase difference, allowing the desired multiple reflection phases to be achieved. In other words, Curve B demonstrates the "desired reflection phase characteristics." In addition, it is preferred that the "desired phase difference" here takes a value close to 360°, but it is not limited to this. In addition, the "targeted multiple desired reflection phases" are preferably multiple reflection phase values ​​that are roughly evenly distributed in 360°. Figure 4In the case where, for example, the element width w has an upper limit on the size of the unit cell and the element width w is limited to less than or equal to 3 mm, a unit cell including an element pattern with a reflection phase of 150°, a unit cell including an element pattern with a reflection phase of 50°, and a unit cell including an element pattern with a reflection phase of -100° can be formed respectively. By setting the reflection control area 10 to include at least the above-mentioned unit cells, a reflection array 1 that functions at a desired operating frequency can be formed. In addition, the specified range of the element width w is determined based on the size in the case of setting it as the reflection array 1. In addition, the multiple reflection phases set as the target are determined based on the reflection phase characteristics required for the reflection array 1. In Figure 4 In the embodiment, the element width w is varied within a predetermined range, but the element length l may also be varied within a predetermined range. In this case, it is also preferable that "the desired reflection phase characteristics can be obtained" when the element length l is varied within the predetermined range.

[0102] On the other hand, observing the changes in the reflection phase shown by curves A and C, curve A does not show phases of 50° and -100°. Furthermore, curve C does not show reflection phases of 150° and 50°. Thus, the targeted multiple reflection phases cannot be achieved within the specified range of element width w, and therefore, curves A and C do not show "desired reflection phase characteristics."

[0103] While the description above uses a cross-patch element pattern 14, the above design method can also be applied to element patterns having other shapes other than cross-patch patterns. Any other shape, such as a circle or square, can be selected. Considering the need for vertically or horizontally polarized waves, a structure that maintains symmetry when rotated 90° is preferred.

[0104] In the above-mentioned design method, the element pattern is designed by determining the element length l and the element width w. However, the parameters for adjusting the configuration of the element pattern, such as "obtaining the desired reflection phase characteristics", are not limited to the element length l and the element width w, and can be appropriately determined according to the element pattern.

[0105] (Manufacturing Method)

[0106] The reflect array 1 can be manufactured in the following manner.

[0107] First, dielectric layer 12 is formed. Dielectric layer 12 is formed into a thin film.

[0108] Next, a ground layer 11 is formed on one surface of the dielectric layer 12. Furthermore, a continuous film for forming the element pattern layer 13 is formed on the remaining surface of the dielectric layer 12. The method for forming the ground layer 11 and the continuous film is appropriately selected from sputtering, vapor deposition, electroplating, and the like, depending on the film thickness. Alternatively, the element pattern layer 13 may be formed by rolling a metal plate.

[0109] Next, the continuous film is processed into the shape of a target element pattern by etching to form the element pattern layer 13. Thus, the reflect array 1 in which the ground layer 11, the dielectric layer 12, and the element pattern layer 13 are stacked in this order can be obtained.

[0110] As described above, the manufacturing method includes the steps of forming the ground layer 11 on the dielectric layer 12 and forming the element pattern layer 13. In addition to the above, the ground layer 11 can be formed by printing a metal slurry, a conductive ink, or the like. In addition to the above, the element pattern layer 13 can be formed by imparting conductivity to the entire dielectric layer 12 and then removing a portion to form a pattern, or by directly forming the element pattern layer 13 on the dielectric layer 12.

[0111] (Evaluation method)

[0112] Whether the desired reflection phase can be obtained is evaluated by simulation. If it can be obtained, the reflection array is designed and manufactured, and the reflection characteristics are evaluated. The evaluation of the reflection characteristics is carried out in a bistatic manner as follows, that is, the transmitter is fixed (perpendicularly injected relative to the sample), and the electromagnetic wave reflected at the designed angle is received by the receiver via the reflection array. Then, the sample evaluated for the reflection characteristics is wound around a core with an inner diameter of 6 inches and a wall thickness of 8 mm, kept for 1 minute, and a bending evaluation is performed to see whether there are any abnormalities in the appearance (breakage, bending marks, etc.) and whether the shape has returned to its original state. Then, as the characteristics after the bending evaluation, the reflection characteristics are evaluated again, and whether there is an impact on the reflection characteristics is confirmed before and after the bending evaluation. In addition, as a bending evaluation index, it is evaluated based on Young's modulus and winding around the core, but it can also be evaluated by indicators such as bending tests of arbitrary curvature radius and bending rigidity.

[0113] [Modification of the first embodiment]

[0114] Figure 5 This is a cross-sectional view of a reflect array 1a according to a modification of the first embodiment. In the modification of the first embodiment, the dielectric layer 12 has multiple layers. In the following description, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals, and their descriptions are simplified or omitted.

[0115] The reflect array 1a includes a dielectric layer 12a formed on a dielectric layer 12. An element pattern layer 13 is formed on the dielectric layer 12a. Dielectric layer 12a can be made of a material different from that used for dielectric layer 12. The manufacturing method can be the same as that used for dielectric layer 12. The thickness ta of dielectric layer 12a can also be appropriately set.

[0116] Furthermore, the reflect array 1a has a structure including two layers, the dielectric layer 12 and the dielectric layer 12a, but the structure is not limited thereto. The number of dielectric layers may be three or more.

[0117] In this way, by changing the number or thickness of the dielectric layer, the reflection phase characteristic and the reflection characteristic can be changed.

[0118] [Second embodiment]

[0119] The second embodiment is different from the first embodiment in that a lamination reinforcing layer is provided. Figure 6 and Figure 7 2 is a cross-sectional view of a reflect array according to Embodiment 2. In the following description, the same reference numerals are used to designate the same or equivalent components as those in Embodiment 1, and the description thereof will be simplified or omitted.

[0120] When interlayer adhesion cannot be achieved between the dielectric layer 12 and the ground layer 11 or between the dielectric layer 12 and the element pattern layer 13, an adhesion enhancement layer can be formed as a layer to enhance adhesion. As the adhesion enhancement layer, for example, an easy-adhesion layer that facilitates adhesion between layers or an adhesive layer having an adhesive force that allows layers to adhere to each other can be used.

[0121] As a method of forming the adhesion reinforcement layer, various versions are conceivable. For example, Figure 6 As shown in the reflect array 1b of (a), a bonding enhancement layer 15 can be formed between the dielectric layer 12 and the ground layer 11, and a bonding enhancement layer 16 can be formed between the dielectric layer 12 and the element pattern layer 13. In addition, in addition to the case where the bonding enhancement layer exists between the two, it is also possible to Figure 6 As shown in the reflect array 1c of (b), only the adhesion reinforcement layer is provided between the dielectric layer 12 and the ground layer 11. Figure 6 As shown in the reflective array 1d of (c), the adhesion enhancement layer is provided only between the dielectric layer 12 and the element pattern layer 13. Figure 7 (a) the reflective array 1e and Figure 7 As shown in the reflective array 1f of (b), a bonding enhancement layer may be provided in accordance with the arrangement of the element pattern layer 13 .

[0122] In the case where the adhesion enhancement layer exists between the dielectric layer 12 and the ground layer 11 and between the dielectric layer 12 and the element pattern layer 13, the same material can be used for each of the adhesion enhancement layers, or different materials can be used. In addition, the adhesion enhancement layer can be composed of two or more layers, or can be a structure in which a plurality of materials are combined.

[0123] Further, Figure 6 The adhesion enhancement layer 16 shown in (c) is formed so as to cover one surface of the dielectric layer 12. It is possible to suppress exposure of the dielectric layer 12 to the external environment, and thus it is possible to expect an effect of suppressing deterioration of the dielectric layer 12. In this way, it is also possible to perform protection of the layer by the formation method of the adhesion enhancement layer.

[0124] (One example of the structure)

[0125] 1. In the case where the adhesion enhancement layer exists between the dielectric layer 12 and the ground layer 11 and between the dielectric layer 12 and the element pattern layer 13, Figure 6 (a), Figure 7 (b)

[0126] 2. In the case where the adhesion enhancement layer exists only between the dielectric layer 12 and the ground layer 11, Figure 6 (b)

[0127] 3. In the case where the adhesion enhancement layer exists only between the dielectric layer 12 and the element pattern layer 13, Figure 6 (c), Figure 7 (a)

[0128] [3rd Embodiment]

[0129] The 3rd embodiment differs from the 1st embodiment in that a functional layer is provided. Figures 8 to 14 is a cross-sectional view of a reflection array to which the 3rd embodiment is applied. In the following description, the same reference numerals are assigned to the same or equivalent structural elements as those of the above-described 1st embodiment, and the description thereof is simplified or omitted.

[0130] (Addition of a function)

[0131] A reflection array can be added with a function as needed. As the added function, for example, there are mentioned a deterioration resistance, an appearance, a protection / scratch resistance, a waterproof property, a gas / water vapor barrier property, a flame retardancy, a non-flammability, a self-extinguishability, a weather resistance, a stain resistance, an antibacterial / antiviral property, a drug resistance, a deodorizing property, an adhesion / bonding property, and the like. One of the above-described functions can be added, or a plurality of functions can be combined.

[0132] As a method of adding functions, a functional layer 17 may be added to the reflect array, or a material that generates functions may be mixed when forming the dielectric layer 12. Alternatively, the reflect array may be coated with a material having functions.

[0133] The functional layer 17 may be formed on at least one of the device pattern layer 13, the ground layer 11, and the dielectric layer 12, depending on the purpose. Furthermore, the functional layer 17 may be formed on the entire surface of the device pattern layer 13, the ground layer 11, and the dielectric layer 12, or may be formed on only a portion of any one of the layers.

[0134] (Function example)

[0135] ○Weather resistance

[0136] As the cause of the deterioration of the reflective array, oxidation caused by exposure to the atmosphere, absorption of water vapor, and deterioration caused by sunlight (ultraviolet rays) can be considered. In order to prevent degradation caused by oxygen and water vapor, it is possible to consider adding a layer with excellent gas barrier properties to the surface of the reflective array. In addition, in order to prevent degradation caused by oxygen, it is preferred that the oxygen permeability of the functional layer is less than or equal to 500cc / m 2 If these conditions are met, thin films can be laminated or a topcoat can be applied by dry or wet coating. Furthermore, the above-mentioned layer can be a single layer or a combination or laminate of multiple layers.

[0137] In order to prevent degradation of the dielectric layer 12 , an antioxidant, a degradation inhibitor, or an antioxidant material may be added when forming the dielectric layer 12 .

[0138] Likewise, in order to prevent degradation caused by water vapor, it is preferable to set the water vapor permeability to be less than or equal to 300 g / m 2 ·Day layer.

[0139] In order to prevent light from sunlight, etc., it is conceivable to provide a film having UV blocking properties or a layer having light shielding properties. In addition, an ultraviolet scattering agent, an ultraviolet absorber, or a light stabilizer may be added.

[0140] ○Appearance

[0141] For example, when installing a reflective array on a building's exterior or interior, it may be considered to provide a visually appealing design to coordinate with the space. Specifically, the visually appealing design can be achieved by affixing a sheet-like material with a visually appealing design to the reflective array using an adhesive, or by fusing the sheet-like material to the reflective array by applying heat or pressure.

[0142] ○ Protection / scratch resistance

[0143] Scratch resistance refers to a function of preventing damage to the reflection array or preventing deterioration of the reflection array itself. As a method of imparting this function, surface hardness can be increased by applying coating processing to the reflection array, or a bar code film can be laminated. As an evaluation of scratch resistance, a pencil hardness test based on JIS K5600-5-4 is performed, and a value of H or more is preferable. In addition, when rubbed with steel wool (#0000) at a load of 1,000 gf / cm 2 preferably no scratch is generated until the number of reciprocating sliding times exceeds 1,000.

[0144] ■Flame retardancy, non-flammability, self-extinguishability

[0145] As a method of imparting flame retardancy and non-flammability to the reflection array, a non-flammable material, quasi-non-flammable material, or difficult-to-burn material that has passed fireproof certification prescribed in the Building Standards Act can be laminated. For example, there are difficult-to-burn fibers, difficult-to-burn plastics, non-flammable paints, and difficult-to-burn paints. As difficult-to-burn fibers, there are halogen compounds, phosphorus compounds, vinylon fibers, polyether imide fibers, aramid fibers, polyester fibers, and vinylon fibers. As difficult-to-burn plastics, inorganic flame retardants such as halogens, phosphorus, aluminum hydroxide, and magnesium hydroxide are added to plastic materials.

[0146] In addition, as a material having self-extinguishability, nylon, polycarbonate, and vinyl chloride are given.

[0147] As a formation method, in addition to lamination of a structure using the above-described materials, the above-described materials can be mixed when the dielectric layer 12 is formed. In addition, if it is a difficult-to-burn plastic or fiber, it can be directly used as a material of the dielectric layer 12.

[0148] ■Antifouling, antibacterial, and antiviral properties

[0149] As a method of imparting antifouling properties to the reflection array, lamination or coating of a substrate having hydrophilicity or hydrophobicity can be considered. As a material having hydrophilicity, a photocatalyst material, a silica-based material, or the like can be used. As a material having hydrophobicity, a fluorine resin, a silicone, or the like can be used. As an antibacterial and antiviral material, a material in which a photocatalyst material, a chlorine compound, a cationic polymer, a metal carrier such as silver or zinc, or the like is included can be used. As a formation method, a method in which the above-described materials are used for lamination as a film or coating processing, the above-described materials are mixed when the dielectric layer 12 is formed, or the like can be adopted.

[0150] (Structure)

[0151] As a formation method of the functional layer, various versions can be considered. For example, a structure in which, for example,Figure 8 and Figure 9 As shown, a functional layer is stacked on the ground layer 11 and the pattern layer 13, or as shown in FIG. Figure 10 As shown, the electrical layer 12 contains a material having additional functions.

[0152] Here, in Figure 8 In (a), the functional layer 17 is formed on the surface of the ground layer 11 facing the -z axis direction, and the functional layer 17 is formed on the element pattern layer 13. Figure 8 In (b), a functional layer 17 is formed on the dielectric layer 12. Figure 8 In (c), the functional layer 17 is formed so as to cover the element pattern 14 , and the functional layer 17 is not formed in a portion where the element pattern 14 is not present.

[0153] In addition, Figure 9 In (a), the functional layer 17 is formed so as to cover the element pattern 14 and the dielectric layer 12. Figure 9 In (b), the functional layer 17 is formed only on the upper surface of the element pattern 14 .

[0154] In addition, Figure 10 In the reflective array 11 of (a), a functional material 18, a material having a function, is mixed in the dielectric layer 12. Figure 10 In the reflect array 1m of (b), a dielectric layer 12a containing a material for performing a function is used. Figure 10 In (c), the functional layer 17 is formed on the dielectric layer 12 in a portion where the element pattern 14 is not formed.

[0155] In the case where the functional layer does not have adhesiveness or cohesiveness, a bonding reinforcement layer may also be used. Figures 11 to 13 , the case where a conformable reinforcement layer is used is shown.

[0156] exist Figure 11 In (a), the adhesion reinforcement layer 19 is formed between the ground layer 11 and the functional layer 17, and the adhesion reinforcement layer 20 is formed between the dielectric layer 12 and the functional layer 17. Figure 11 In (b), the adhesion-enhancing layer 20 formed between the dielectric layer 12 and the functional layer 17 is formed only on the upper surface of the element pattern 14. Figure 11 In (c), the functional layer 17 is formed to have the same configuration as the element pattern 14 .

[0157] In addition, Figure 12 In (a), the functional layer 17 is not formed on the layer facing the +z axis, and the adhesion enhancement layer 19 is formed between the functional layer 17 and the ground layer 11. Figure 12In (b), the functional layer 17 is not formed on the layer facing the -z axis, and the adhesion enhancement layer 20 is formed between the functional layer 17 and the dielectric layer 12. Figure 12 In (c), the adhesion-enhancing layer 20 is formed only on the upper surface of the element pattern 14 .

[0158] In addition, Figure 13 In FIG, the functional layer 17 is formed to have the same configuration as the element pattern 14. Figure 13 In (b) and (c), the functional layer 17 is formed so as to also cover the end portions of the reflect arrays 1v and 1w.

[0159] As described above, the functional layer 17 may be formed on both the ground layer 11 side and the element pattern layer 13 side, or may be formed only on the ground layer 11 side or only on the element pattern layer 13 side. Furthermore, it may be formed on the dielectric layer 12. When functional layers are formed on both the ground layer 11 and the element pattern layer 13, a structure having the same function or a structure having different functions may be formed. When the functional layers are stacked, they may be a single layer or multiple layers. Furthermore, even when the functional layer is composed of a single layer, materials having multiple functions may be combined within the single layer.

[0160] (An example of a structure)

[0161] 1. When functional layers exist in both the ground layer 11 and the element pattern layer 13 ( Figure 8 、 9 )

[0162] 2. When the functional layer exists only on the ground layer 11 side ( Figure 12 (a)

[0163] 3. When the functional layer exists only on the element pattern layer 13 side ( Figure 12 (b) Figure 12 (c) Figure 13 )

[0164] 4. When the functional layer exists only in the dielectric layer 12 ( Figure 10 (c))

[0165] 5. In the case where a functional layer is formed at the end of the reflective array ( Figure 13 (b) Figure 13 (c))

[0166] 6. In the case where both the ground layer 11 and the element pattern layer 13 have functional layers and a bonding enhancement layer ( Figure 11 )

[0167] 7, only in the case where there is a functional layer and a bonding reinforcement layer on the ground layer 11 ( Figure 12(a))

[0168] 8, only in the case where the functional layer exists and the adhesion enhancement layer exists in the element pattern layer 13 Figure 12 (b), Figure 12 (c), Figure 13 (a))

[0169] 9, in the case where the functional material 18 is mixed in the dielectric layer 12 layer Figure 10 (a))

[0170] In addition, the above-described structures 1 to 8 can also be combined. For example, structure 1 and structure 9 can also be combined to form a structure as shown in the reflection array 1x of Figure 14 .

[0171] (Evaluation results)

[0172] In the case where the operation frequency is set to 28 GHz to 100 GHz and the incidence angle is 0° and the reflection angle is 45°, the design and production of the reflection array were performed. The examples and comparative examples were produced based on the configuration formed by the ground layer 11, the dielectric layer 12, and the element pattern layer 13 of the first embodiment, and evaluation was performed. Figure 15 is a graph showing the evaluation results of whether the reflection control region can obtain the desired reflection phase characteristics by simulation. Figure 16 is a graph showing the evaluation results in the case where the reflection array is produced.

[0173] As the evaluation items, there are “phase shift confirmation”, “reflection characteristics”, “bending evaluation after characteristics”, and “flexibility”. In Table 1, the evaluation criteria are shown with respect to each item. “Phase shift confirmation” shows that “obtaining the desired reflection phase characteristics” can be achieved by the design described above. “Reflection characteristics” shows that the peak value (for example, the maximum value) of the intensity of the electromagnetic wave can be obtained at the designed operation frequency, incidence angle, and reflection angle. “Flexibility” shows that there are no appearance abnormalities such as wrinkles or breakage in appearance when the sample is wound around a core with an inner diameter of 6 inches and a wall thickness of 8 mm and is kept for 1 minute, and “bending evaluation after characteristics” shows that the change rate of the peak value of the intensity of the reflected wave is within ±3% when measured under the same conditions as when the reflection characteristics of the sample after the evaluation of the flexibility are evaluated. In the case where the evaluation criteria described below are satisfied, “〇” is marked in Figure 15 and Figure 16 , and “X” is marked in the case where they are not satisfied.

[0174] [Table 1]

[0175]

[0176] (Example 1)

[0177] 200 μm thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, 2 μm thick Cu layers were formed by electroplating as a base layer for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The dielectric constant of the PET used was 3.03, and the dielectric loss tangent was 0.00476.

[0178] like Figure 15 As shown in the simulation, the operating frequency is 28 GHz, λ0 is 10.7 mm, the thickness t of the dielectric layer 12 is 200 μm, the total thickness (i.e., the thickness of the reflection control region, which is the same as the thickness of the reflect array when a reflect array is fabricated) is 204 μm, the unit cell size is 5.047 mm, and the element length l is 3.0 mm. The conditions of equations (6) and (7) are satisfied, and as shown by 0 in the "Phase Shift Confirmation" field, the desired reflection phase characteristics can be obtained.

[0179] In addition, if Figure 16 As shown in the figure, a reflective array consisting of three unit cells was formed and evaluated. As both the "Reflection Characteristics" and "Flexibility" values ​​were 0, the evaluation results met the required level. Furthermore, as the "Evaluation Characteristics after Bending" value was 0, the flexibility evaluation showed no effect on the reflective characteristics. All evaluation results were good, so they were recorded as 0. As the comprehensive evaluation value was 0, the reflective array requirements were met.

[0180] (Example 2)

[0181] 100 μm thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, 2 μm thick Cu layers were formed by electroplating as a base layer for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The dielectric constant of the PET used was 3.03, and the dielectric loss tangent was 0.00476.

[0182] like Figure 15 As shown in the simulation, the operating frequency is 28 GHz, λ0 is 10.7 mm, the thickness t of the dielectric layer 12 is 100 μm, the total thickness is 104 μm, the unit cell size is 3.785 mm, and the element length l is 3.0 mm. The conditions of equations (6) and (7) are satisfied, and as shown by the "Phase Shift Confirmation" value of 0, the desired reflection phase characteristics are achieved.

[0183] In addition, if Figure 16As shown in the figure, a reflective array consisting of four unit cells was formed and evaluated. As both the "Reflection Characteristics" and "Flexibility" values ​​were 0, the evaluation results met the required level. Furthermore, as the "Evaluation Characteristics after Bending" value was 0, the flexibility evaluation showed no effect on the reflective characteristics. All evaluation results were good, so they were recorded as 0. As the comprehensive evaluation value was 0, the reflective array requirements were met.

[0184] (Example 3)

[0185] 200 μm thick polytetrafluoroethylene (PTFE) was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, 2 μm thick Cu layers were formed by electroplating as the base layers for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The PTFE used has a dielectric constant of 2.06 and a dielectric loss tangent of 0.0007.

[0186] like Figure 15 As shown in the simulation, the operating frequency is 28 GHz, λ0 is 10.7 mm, the thickness t of the dielectric layer 12 is 200 μm, the total thickness is 204 μm, the unit cell size is 3.785 mm, and the element length l is greater than or equal to 3.1 mm and less than or equal to 3.6 mm. The conditions of equations (6) and (7) are satisfied, and as shown by the "Phase Shift Confirmation" value of 0, the desired reflection phase characteristics can be obtained.

[0187] In addition, if Figure 16 As shown in the figure, a reflective array consisting of four unit cells was formed and evaluated. As both the "Reflection Characteristics" and "Flexibility" values ​​were 0, the evaluation results met the required level. Furthermore, as the "Evaluation Characteristics after Bending" value was 0, the flexibility evaluation showed no effect on the reflective characteristics. All evaluation results were good, so they were recorded as 0. As the comprehensive evaluation value was 0, the reflective array requirements were met.

[0188] (Example 4)

[0189] A 100μm-thick cycloolefin polymer was used as the dielectric layer 12. A 2μm-thick Cu layer was formed on both surfaces of the dielectric layer 12 by electroplating, serving as a base for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The cycloolefin polymer used has a dielectric constant of 2.32 and a dielectric loss tangent of 0.00039.

[0190] like Figure 15As shown in the simulation, the operating frequency is 28 GHz, λ0 is 10.7 mm, the thickness t of the dielectric layer 12 is 100 μm, the total thickness is 104 μm, the unit cell size is 3.785 mm, and the element length l is greater than or equal to 3.24 mm and less than or equal to 3.53 mm. The conditions of equations (6) and (7) are satisfied, and as shown by the "Phase Shift Confirmation" value of 0, the desired reflection phase characteristics are obtained.

[0191] In addition, if Figure 16 As shown in the figure, a reflective array consisting of four unit cells was formed and evaluated. As both the "Reflection Characteristics" and "Flexibility" values ​​were 0, the evaluation results met the required level. Furthermore, as the "Evaluation Characteristics after Bending" value was 0, the flexibility evaluation showed no effect on the reflective characteristics. All evaluation results were good, so they were recorded as 0. As the comprehensive evaluation value was 0, the reflective array requirements were met.

[0192] (Example 5)

[0193] A 50μm-thick polystyrene was used as the dielectric layer 12. A 2μm-thick Cu layer was formed on both surfaces of the dielectric layer 12 by electroplating, serving as a base for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The polystyrene used has a dielectric constant of 2.32 and a dielectric loss tangent of 0.00039.

[0194] like Figure 15 As shown in the simulation, the operating frequency is 28 GHz, λ0 is 10.7 mm, the thickness t of the dielectric layer 12 is 50 μm, the total thickness is 54 μm, the unit cell size is 3.785 mm, and the element length l is 3.45 mm. The conditions of equations (6) and (7) are satisfied, and as shown by the "Phase Shift Confirmation" value of 0, the desired reflection phase characteristics can be obtained.

[0195] In addition, if Figure 16 As shown in the figure, a reflective array consisting of four unit cells was formed and evaluated. As both the "Reflection Characteristics" and "Flexibility" values ​​were 0, the evaluation results met the required level. Furthermore, as the "Evaluation Characteristics after Bending" value was 0, the flexibility evaluation showed no effect on the reflective characteristics. All evaluation results were good, so they were recorded as 0. As the comprehensive evaluation value was 0, the reflective array requirements were met.

[0196] (Example 6)

[0197] A 100-μm-thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, a 300-nm-thick Cu layer was formed by a vapor deposition method as a layer to be a basis of the ground layer 11 and the element pattern layer 13. The element pattern layer 13 was formed by etching one of the Cu layers. Further, the dielectric constant of the PET used was 3.03, and the dielectric loss tangent was 0.00476.

[0198] As shown in Table 1, in the simulation, the operation frequency was 28 GHz, λ0was 10.7 mm, the thickness t of the dielectric layer 12 was 100 μm, the total thickness was 104 μm, the unit cell size was 5.047 mm, and the element length 1 was 3.0 mm. The conditions of the formula (6) and the formula (7) were satisfied, and as shown by O in "Phase shift confirmation", the desired reflection phase characteristic could be obtained. Figure 15

[0199] As shown in Table 1, in the simulation, the operation frequency was 28 GHz, λ0was 10.7 mm, the thickness t of the dielectric layer 12 was 100 μm, the total thickness was 104 μm, the unit cell size was 5.047 mm, and the element length 1 was 3.0 mm. The conditions of the formula (6) and the formula (7) were satisfied, and as shown by O in "Phase shift confirmation", the desired reflection phase characteristic could be obtained. Figure 16

[0200] (Example 7)

[0201] A 100-μm-thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, a 300-nm-thick Al layer was formed by a vapor deposition method as a layer to be a basis of the ground layer 11 and the element pattern layer 13. The element pattern layer 13 was formed by etching one of the Al layers. Further, the dielectric constant of the PET used was 3.03, and the dielectric loss tangent was 0.00476.

[0202] As shown in Table 1, in the simulation, the operation frequency was 28 GHz, λ0was 10.7 mm, the thickness t of the dielectric layer 12 was 100 μm, the total thickness was 104 μm, the unit cell size was 5.047 mm, and the element length 1 was 3.0 mm. The conditions of the formula (6) and the formula (7) were satisfied, and as shown by O in "Phase shift confirmation", the desired reflection phase characteristic could be obtained. Figure 15

[0203] As shown in Table 1, in the simulation, the operation frequency was 28 GHz, λ0was 10.7 mm, the thickness t of the dielectric layer 12 was 100 μm, the total thickness was 104 μm, the unit cell size was 5.047 mm, and the element length 1 was 3.0 mm. The conditions of the formula (6) and the formula (7) were satisfied, and as shown by O in "Phase shift confirmation", the desired reflection phase characteristic could be obtained. Figure 16 ​​​As shown in the figure, a reflective array consisting of three unit cells was formed and evaluated. As both the "Reflection Characteristics" and "Flexibility" values ​​were 0, the evaluation results met the required level. Furthermore, as the "Evaluation Characteristics after Bending" value was 0, the flexibility evaluation showed no effect on the reflective characteristics. All evaluation results were good, so they were recorded as 0. As the comprehensive evaluation value was 0, the reflective array requirements were met.

[0204] (Example 8)

[0205] 50 μm thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, 300 nm thick Cu layers were formed by electroplating as the base layers for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The dielectric constant of the PET used was 3.03, and the dielectric loss tangent was 0.00476.

[0206] like Figure 15 As shown in the simulation, the operating frequency is 60 GHz, λ0 is 4.99 mm, the thickness t of the dielectric layer 12 is 50 μm, the total thickness is 50.6 μm, the unit cell size is 2.355 mm, and the element length l is 1.40 mm. The conditions of equations (6) and (7) are satisfied, and as shown by the "Phase Shift Confirmation" value of 0, the desired reflection phase characteristics are achieved.

[0207] In addition, if Figure 16 As shown in the figure, a reflective array consisting of three unit cells was formed and evaluated. As both the "Reflection Characteristics" and "Flexibility" values ​​were 0, the evaluation results met the required level. Furthermore, as the "Evaluation Characteristics after Bending" value was 0, the flexibility evaluation showed no effect on the reflective characteristics. All evaluation results were good, so they were recorded as 0. As the comprehensive evaluation value was 0, the reflective array requirements were met.

[0208] (Example 9)

[0209] 200 μm thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, 300 nm thick Cu layers were formed by electroplating as a base layer for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The dielectric constant of the PET used was 3.03, and the dielectric loss tangent was 0.00476.

[0210] like Figure 15As shown in the simulation, the operating frequency is 60 GHz, λ0 is 4.99 mm, the thickness t of the dielectric layer 12 is 200 μm, the total thickness is 200.6 μm, the unit cell size is 2.355 mm, and the element length l is 1.50 mm. The conditions of equations (6) and (7) are satisfied, and as shown by the "Phase Shift Confirmation" value of 0, the desired reflection phase characteristics are achieved.

[0211] In addition, if Figure 16 As shown in the figure, a reflective array consisting of three unit cells was formed and evaluated. As both the "Reflection Characteristics" and "Flexibility" values ​​were 0, the evaluation results met the required level. Furthermore, as the "Evaluation Characteristics after Bending" value was 0, the flexibility evaluation showed no effect on the reflective characteristics. All evaluation results were good, so they were recorded as 0. As the comprehensive evaluation value was 0, the reflective array requirements were met.

[0212] (Example 10)

[0213] 20 μm thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, 300 nm thick Cu layers were formed by electroplating as a base layer for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The PET used had a dielectric constant of 3.03 and a dielectric loss tangent of 0.00476.

[0214] like Figure 15 As shown in Figure 2, in the simulation, the operating frequency was 100 GHz, λ0 was 2.99 mm, the thickness t of the dielectric layer 12 was 20 μm, the total thickness was 20.6 μm, the unit cell size was 1.413 mm, and the element length l was 0.90 mm. The conditions of equations (6) and (7) were satisfied, and as shown by the "Phase Shift Confirmation" value of 0, the desired reflection phase characteristics were achieved.

[0215] In addition, if Figure 16 As shown in the figure, a reflective array consisting of three unit cells was formed and evaluated. As both the "Reflection Characteristics" and "Flexibility" values ​​were 0, the evaluation results met the required level. Furthermore, as the "Evaluation Characteristics after Bending" value was 0, the flexibility evaluation showed no effect on the reflective characteristics. All evaluation results were good, so they were recorded as 0. As the comprehensive evaluation value was 0, the reflective array requirements were met.

[0216] (Example 11)

[0217] 50 μm thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, 300 nm thick Cu layers were formed by electroplating as a base layer for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The PET used had a dielectric constant of 3.03 and a dielectric loss tangent of 0.00476.

[0218] like Figure 15 As shown in the simulation, the operating frequency is 100 GHz, λ0 is 2.99 mm, the thickness t of the dielectric layer 12 is 50 μm, the total thickness is 50.6 μm, the unit cell size is 1.413 mm, and the element length l is 0.90 mm. The conditions of equations (6) and (7) are satisfied, and as shown by the "Phase Shift Confirmation" value of 0, the desired reflection phase characteristics can be obtained.

[0219] In addition, if Figure 16 As shown in the figure, a reflective array consisting of three unit cells was formed and evaluated. As both the "Reflection Characteristics" and "Flexibility" values ​​were 0, the evaluation results met the required level. Furthermore, as the "Evaluation Characteristics after Bending" value was 0, the flexibility evaluation showed no effect on the reflective characteristics. All evaluation results were good, so they were recorded as 0. As the comprehensive evaluation value was 0, the reflective array requirements were met.

[0220] (Comparative Example 1)

[0221] 300 μm thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, 2 μm thick Cu layers were formed by electroplating as a base layer for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The dielectric constant of the PET used was 3.03, and the dielectric loss tangent was 0.00476.

[0222] like Figure 15 As shown in the simulation, the operating frequency is 28 GHz, λ0 is 10.7 mm, the thickness t of the dielectric layer 12 is 300 μm, the total thickness is 304 μm, the unit cell size is 5.047 mm, and the element length l is 3.50 mm. The condition "whether l ≥ 4.4" included in equation (6) is satisfied, but the condition of equation (7) is not satisfied. Furthermore, as indicated by the "×" in the "Phase Shift Confirmation" field, the desired reflection phase characteristics cannot be obtained.

[0223] In addition, if Figure 16 As shown, the desired reflection phase characteristics cannot be obtained in the reflection control region, and thus the reflect array is not formed.

[0224] (Comparative Example 2)

[0225] A 764μm-thick fluororesin-impregnated glass cloth was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, 18μm-thick Cu layers were formed by electroplating as a base layer for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The dielectric layer used had a dielectric constant of 2.6 and a dielectric loss tangent of 0.0025.

[0226] like Figure 15 As shown in the simulation, the operating frequency is 28 GHz, λ0 is 10.7 mm, the thickness t of the dielectric layer 12 is 764 μm, the total thickness is 800 μm, the unit cell size is 5.047 mm, and the element length l is greater than or equal to 2.21 mm and less than or equal to 3.31 mm. The conditions of equations (6) and (7) are not met. Furthermore, as indicated by the "×" in the "Phase Shift Confirmation" field, the desired reflection phase characteristics cannot be obtained.

[0227] In addition, if Figure 16 As shown in the figure, a reflective array consisting of three unit cells was formed and evaluated. As shown by the "Reflection Characteristics" score of 0, the required level was met. However, as shown by the "Flexibility" and "Post-Bending Evaluation Characteristics" scores of ×, favorable evaluation results were not obtained. As shown by the "Comprehensive Evaluation" score of ×, the reflective array requirements were not met.

[0228] (Comparative Example 3)

[0229] A 600 μm thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, a 2 μm thick Cu layer was formed by electroplating as a base layer for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The PET used had a dielectric constant of 3.03 and a dielectric loss tangent of 0.00476.

[0230] like Figure 15 As shown in the simulation, the operating frequency is 28 GHz, λ0 is 10.7 mm, the thickness t of the dielectric layer 12 is 600 μm, the total thickness is 604 μm, the unit cell size is 5.047 mm, and the element length l is 3.0 mm. The condition in equation (6) satisfies "l ≥ 4.4" as indicated by 0, but does not satisfy "0.001 < t < 0.25" as indicated by ×. Furthermore, satisfying the condition in equation (7), as indicated by 0 in the "Phase Shift Confirmation" field, allows for the desired reflection phase characteristics to be achieved.

[0231] In addition, if Figure 16As shown, a reflection array including 3 unit cells was formed and evaluated. As shown by O in "Reflection characteristics", the required level was satisfied. However, as shown by X in "Flexibility" and "Evaluation characteristics after bending", no good evaluation results were obtained. As shown by X in the comprehensive evaluation, the requirements for the reflection array were not satisfied.

[0232] (Comparative Example 4)

[0233] A 1000 μm thick PET was used as the dielectric layer 12. On both sides of the dielectric layer 12, a 2 μm thick Cu layer was formed as a layer to be the basis of the ground layer 11 and the element pattern layer 13 by plating processing. The element pattern layer 13 was formed by etching one of the Cu layers. Further, the dielectric constant of the PET used was 3.03 and the dielectric loss tangent was 0.00476.

[0234] As shown in Figure 15 , in the simulation, the operation frequency was 28 GHz, λ0was 10.7 mm, the thickness t of the dielectric layer 12 was 1000 μm, the total thickness was 1004 μm, the unit cell size was 5.047 mm, and the element length 1 was 2.5 mm. For the condition of Equation (6), as shown by O, "whether l≥4.4 is satisfied", but as shown by X, "0.001

[0235] Further, as shown in Figure 16 , the desired reflection phase characteristics could not be obtained in the reflection control region, and thus a reflection array was not formed.

[0236] (Comparative Example 5)

[0237] A 500 μm thick PET was used as the dielectric layer 12. On both sides of the dielectric layer 12, a 2 μm thick Cu layer was formed as a layer to be the basis of the ground layer 11 and the element pattern layer 13 by plating processing. The element pattern layer 13 was formed by etching one of the Cu layers. Further, the dielectric constant of the PET used was 3.03 and the dielectric loss tangent was 0.00476.

[0238] As shown in Figure 15 , in the simulation, the operation frequency was 60 GHz, λ0was 4.99 mm, the thickness t of the dielectric layer 12 was 500 μm, the total thickness was 504 μm, the unit cell size was 2.355 mm, and the element length 1 was 0.2 mm. Neither the condition of Equation (6) nor the condition of Equation (7) was satisfied. Further, as shown by X in "Phase shift confirmation", the desired reflection phase characteristics could not be obtained.

[0239] In addition, if Figure 16 As shown, the desired reflection phase characteristics cannot be obtained in the reflection control region, and thus the reflect array is not formed.

[0240] (Comparative Example 6)

[0241] A 1000 μm thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, a 2 μm thick Cu layer was formed by electroplating as a base layer for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The PET used had a dielectric constant of 3.03 and a dielectric loss tangent of 0.00476.

[0242] like Figure 15 As shown in the simulation, the operating frequency is 60 GHz, λ0 is 4.99 mm, the thickness t of the dielectric layer 12 is 1000 μm, the total thickness is 1004 μm, the unit cell size is 2.355 mm, and the element length l is 2 mm. The condition in equation (6) is satisfied, as indicated by 0, "whether l ≥ 4.4" is satisfied. However, the condition "0.001 < t < 0.25" is not satisfied, as indicated by ×. Furthermore, the condition in equation (7) is not satisfied. As indicated by × in the "Phase Shift Confirmation" field, the desired reflection phase characteristics cannot be obtained.

[0243] In addition, if Figure 16 As shown, the desired reflection phase characteristics cannot be obtained in the reflection control region, and thus the reflect array is not formed.

[0244] (Comparative Example 7)

[0245] 250 μm thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, 2 μm thick Cu layers were formed by electroplating as the base layers for the ground layer 11 and the device pattern layer 13. One of the Cu layers was etched to form the device pattern layer 13. The dielectric constant of the PET used was 3.03, and the dielectric loss tangent was 0.00476.

[0246] like Figure 15 As shown in the simulation, the operating frequency is 100 GHz, λ0 is 2.99 mm, the thickness t of the dielectric layer 12 is 250 μm, the total thickness is 254 μm, the unit cell size is 1.413 mm, and the element length l is 0.08 mm. Neither the conditions of equations (6) nor (7) are satisfied. Furthermore, as indicated by the "×" in the "Phase Shift Confirmation" field, the desired reflection phase characteristics cannot be obtained.

[0247] In addition, if Figure 16As shown in "Reflection characteristics", the reflection array was not formed. As shown in "Reflection characteristics" by X, the required level was not satisfied. Further, as shown by Δ in "Flexibility", a case where the allowable level was reached depending on the sample was found. As shown by X in the comprehensive evaluation, the requirements of the reflection array were not satisfied.

[0248] (Comparative Example 8)

[0249] A 200-μm-thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, a 2-μm-thick Cu layer was formed as a layer to be the basis of the ground layer 11 and the element pattern layer 13 by electroplating processing. The element pattern layer 13 was formed by etching one of the Cu layers. Further, the dielectric constant of the PET used was 3.03, and the dielectric loss tangent was 0.00476.

[0250] As shown in "Reflection characteristics", the reflection array was not formed. As shown in "Reflection characteristics" by X, the required level was not satisfied. Further, as shown by Δ in "Flexibility", a case where the allowable level was reached depending on the sample was found. As shown by X in the comprehensive evaluation, the requirements of the reflection array were not satisfied. Figure 17 As shown in "Reflection characteristics", the reflection array was not formed. As shown in "Reflection characteristics" by X, the required level was not satisfied. Further, as shown by Δ in "Flexibility", a case where the allowable level was reached depending on the sample was found. As shown by X in the comprehensive evaluation, the requirements of the reflection array were not satisfied.

[0251] As shown in "Reflection characteristics", the reflection array was not formed. As shown in "Reflection characteristics" by X, the required level was not satisfied. Further, as shown by Δ in "Flexibility", a case where the allowable level was reached depending on the sample was found. As shown by X in the comprehensive evaluation, the requirements of the reflection array were not satisfied. Figure 18 (Comparative Example 9)

[0252] A 400-μm-thick PET was used as the dielectric layer 12. On both surfaces of the dielectric layer 12, a 2-μm-thick Cu layer was formed as a layer to be the basis of the ground layer 11 and the element pattern layer 13 by electroplating processing. The element pattern layer 13 was formed by etching one of the Cu layers. Further, the dielectric constant of the PET used was 3.03, and the dielectric loss tangent was 0.00476.

[0253] As shown in "Reflection characteristics", the reflection array was not formed. As shown in "Reflection characteristics" by X, the required level was not satisfied. Further, as shown by Δ in "Flexibility", a case where the allowable level was reached depending on the sample was found. As shown by X in the comprehensive evaluation, the requirements of the reflection array were not satisfied.

[0254] Figure 17 ​As shown in the simulation, the operating frequency is 100 GHz, λ0 is 2.99 mm, the thickness t of the dielectric layer 12 is 400 μm, the total thickness is 404 μm, the unit cell size is 1.413 mm, and the element length l is 0.5 mm. Neither the conditions of equations (6) nor (7) are satisfied. Furthermore, as indicated by the "×" in the "Phase Shift Confirmation" field, the desired reflection phase characteristics cannot be obtained.

[0255] In addition, if Figure 18 As shown, the desired reflection phase characteristics cannot be obtained in the reflection control region, and thus the reflect array is not formed.

[0256] (Action / Effect)

[0257] According to the present invention, when manufacturing a reflect array having a structure including a ground layer, a dielectric layer, and an element pattern layer, the thickness of the dielectric layer is set within the range specified by equation (6) or (7). This ensures ease of manufacture, while achieving the reflective characteristics and flexibility required for a reflect array, thereby enabling thinner and lighter reflect arrays.

[0258] Furthermore, by simulating the structures of the ground layer, dielectric layer, and element pattern layer in advance, it is possible to derive specific structures such as the thickness (total thickness), unit cell size, and element width of the reflect array that can achieve desired reflection phase characteristics.

[0259] Furthermore, according to the present invention, the flexibility of the reflect array can be ensured, and thus the reflect array can be installed and replaced with ease and lightness.

[0260] Specific advantages of thinning include the following.

[0261] Roll-to-roll production is possible, enabling the production of large-area reflectors. Furthermore, production costs and time can be reduced.

[0262] Reduce the use of etching solutions and waste treatment chemicals, shorten etching time, and protect the environment.

[0263] During installation, it can be lightweight and reduce the burden on the operator. In addition, it can be attached to curved surfaces.

[0264] The thickness is thin, and accordingly, space saving can be achieved.

[0265] Furthermore, while the present invention illustrates a case where unit cells are arranged in one direction, the x-axis, as the reflection control region 10, the present invention is not limited to this case. If the reflection control region 10 includes the ground layer 11, the dielectric layer 12, and the element pattern layer 13, the present invention can also be applied to a case where unit cells are arranged in both the x-axis and y-axis directions.

[0266] [Fourth embodiment]

[0267] The fourth embodiment is different from the first embodiment in that the element pattern 14 includes shapes other than the cross patch. Figure 17 and Figure 17 The element pattern layer 13 may include Figure 17 as well as Figure 18 The device pattern shown here also describes the setting of the device length l of the device pattern used as a parameter during design.

[0268] In the following description, the same reference numerals are used to denote the same or equivalent components as those in the first embodiment, and the description thereof will be simplified or omitted.

[0269] Figure 18 (a) is a diagram showing an element pattern 141. The element pattern 141 shows a shape in which two rectangular square patches are intersected, and the sizes of the square patches 141-1 and 141-2 are different. The length of the long side direction of the square patch 141-1 is set to l1, and the length of the long side direction of the square patch 141-2 is set to l2. Here, l2 is shorter than l1, and l2 can be used as the element length l when applying formula (6). When L2 satisfies formula (6), l1 also satisfies formula (6), so it is preferred to set the shorter length of the representative side lengths of the shape of the specified element pattern as the element length l, so as to achieve the element pattern as a whole satisfying formula (6).

[0270] Figure 18 (b) is a diagram showing the element pattern 142. The element pattern 142 has a circular shape with a diameter d. In this case, d can be used as the element length l of the element pattern 142.

[0271] Figure 18 (c) is a diagram showing the element pattern 143. The element pattern 143 has an elliptical shape, with the major diameter being ld and the minor diameter being sd. In this case, sd can be used as the element length l of the element pattern 143.

[0272] ​ (a) is a diagram showing an element pattern 144. The element pattern 144 has a square shape, and the length of one side is l4. In this case, l4 can be used as the element length l of the element pattern 144.

[0273] ​(b) is a diagram showing the element pattern 145. The element pattern 145 has a rectangular shape, with the length of the short side being l5-1 and the length of the long side being l5-2. In this case, l5-1 can be used as the element length l of the element pattern 145.

[0274] ​ (c) shows element patterns 146-1 and 146-2. Element pattern 146-1 has an isosceles triangle shape, with two sides of length l6-1 forming a right angle, and the length of the side opposite the right angle is l6-2. In this case, l6-1 can be used as the element length l of element pattern 146-1.

[0275] The element pattern 146-2 is a right triangle with side lengths 16-3, 16-4, and 16-5. In this case, the shortest side length 16-3 can be used as the element length 1 of the element pattern 146-2.

[0276] ​ (d) is a diagram showing element patterns 147-1 and 147-2. The element pattern 147-1 has a quadrilateral shape, and the shortest length of its sides is 16. In this case, 16 can be used as the element length 1 of the element pattern 147-1.

[0277] The element pattern 147-2 has a hexagonal shape, and the shortest length of its sides is 17. In this case, 17 can be used as the element length 1 of the element pattern 147-2.

[0278] When a polygon is used as the element pattern as described above, the shortest length of the sides can be used as the element length l of the element pattern.

[0279] As described above, the element length l can be set for each shape of the element pattern. Furthermore, when the element pattern is polygonal, the length of the shortest side is set as the element length l, but the present invention is not limited to this. For example, the length of the longest side can also be set as the element length l.

[0280] In addition, the shape of the element pattern is not limited to the shape of the present invention. For example, the shapes of the element patterns shown in the present invention may be combined to form an element pattern having a desired shape.

[0281] [Other embodiments]

[0282] The following describes the possible ways in which the present invention can be formed, but the present invention is not limited thereto.

[0283] (Method 1)

[0284] A reflective array comprises a ground layer, a dielectric layer, and an element pattern layer having a plurality of element patterns, wherein:

[0285] The thickness t (mm) of the dielectric layer and the length l (mm) of the plurality of element patterns satisfy the following relationship.

[0286] [Formula 5]

[0287] l≥4.4×t and 0.001<t<0.25.

[0288] (Method 2)

[0289] The reflect array according to embodiment 1 is characterized in that:

[0290] The wavelength at the design frequency, i.e., the wavelength λ0 (mm), and the thickness of the dielectric layer, i.e., the thickness t (mm), satisfy the following relationship:

[0291] [Formula 6]

[0292] 0.001 <t<0.065×λ0...(7)。

[0293] (Method 3)

[0294] The reflect array according to embodiment 1 or 2, characterized in that:

[0295] The surface resistance of the ground layer is less than or equal to 100Ω / □.

[0296] (Method 4)

[0297] The reflectarray according to any one of aspects 1 to 3, wherein:

[0298] At least one of the ground layer and the element pattern layer is formed of Cu or Al.

[0299] (Method 5)

[0300] The reflect array according to embodiment 4 is characterized in that:

[0301] The at least one layer has a thickness less than or equal to 1 μm.

[0302] (Method 6)

[0303] The reflectarray according to any one of aspects 1 to 5, characterized in that:

[0304] The width of the element pattern, ie, the element width w, is less than or equal to 3 mm.

[0305] (Method 7)

[0306] The reflect array according to any one of aspects 1 to 6, wherein:

[0307] By changing the width of the element pattern, that is, the element width w, within a predetermined range, a desired reflection phase characteristic can be obtained.

[0308] (Method 8)

[0309] The reflectarray according to any one of aspects 1 to 7, wherein:

[0310] Also includes fit reinforcement.

[0311] (Method 9)

[0312] The reflectarray according to any one of aspects 1 to 8, wherein:

[0313] Also includes functional layers.

[0314] While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0315] Description of the label

[0316] 1. 1a~1x: reflective array, 10: reflection control area, 11: ground layer, 12, 12a: dielectric layer, 13: element pattern layer, 14, 14a~14d, 141~145, 146-1, 146-2, 147-1, 147-2: element pattern, 15, 16, 19, 20: bonding enhancement layer, 17: functional layer, 18: functional material.

Claims

1. A reflective array comprising a ground layer, a dielectric layer, and an element pattern layer having a plurality of element patterns, The reflective array is characterized in that The thickness of the dielectric layer, i.e., the thickness t (mm), and the length of the plurality of element patterns, i.e., the element length l (mm), satisfy the following relationship: [Formula 1] l≥4.4×t and 0.001<t<0.

25.

2. The reflective array according to claim 1, wherein: The wavelength at the design frequency, i.e., the wavelength λ0 (mm), and the thickness of the dielectric layer, i.e., the thickness t (mm), satisfy the following relationship: [Formula 2] 0.001<t<0.065×λ0…(7).

3. The reflective array according to claim 1, wherein: The surface resistance of the ground layer is less than or equal to 100Ω / □.

4. The reflective array according to claim 1, wherein: At least one of the ground layer and the element pattern layer is formed of Cu or Al.

5. The reflective array according to claim 4, wherein: The thickness of the at least one layer is less than or equal to 1 μm.

6. The reflective array according to claim 1 or 2, characterized in that: The width of the element pattern, ie, the element width w, is less than or equal to 3 mm.

7. The reflective array according to claim 1 or 2, characterized in that: By changing the width of the element pattern, that is, the element width w, within a predetermined range, a desired reflection phase characteristic can be obtained.

8. The reflective array according to claim 1, wherein: Also includes fit reinforcement.

9. The reflective array according to claim 1, wherein: Also includes functional layers.

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