Electromagnetic wave deflection sheet and method for manufacturing an electromagnetic wave deflection sheet

Abstract

To provide an electromagnetic wave deflection sheet that can deflect high-frequency electromagnetic waves in a specific direction with a simple configuration, and a method for manufacturing such an electromagnetic wave deflection sheet that can be manufactured efficiently. [Solution] The electromagnetic wave deflection sheet of the present invention is an electromagnetic wave deflection sheet that deflects the transmission direction of electromagnetic waves incident on a main surface with respect to the incident direction, and comprises a plurality of first portions containing a first resin material and a plurality of second portions having a relative permittivity different from that of the first portions, wherein the first portions and the second portions have portions that are aligned in a first direction within the main surface.

Description

Technical Field

[0001] The present invention relates to an electromagnetic wave deflection sheet and a method for manufacturing the electromagnetic wave deflection sheet.

Background Art

[0002] With the increase in speed and capacity of communication devices such as smartphones and tablets, it has been proposed to use high-frequency bands such as 1 GHz or more and 5 GHz or less as the bands of electromagnetic waves transmitted and received by these communication devices (see, for example, Patent Document 1). In recent years, even higher frequency bands have been used to improve communication speed and communication capacity.

[0003] Such high-frequency band electromagnetic waves have higher straightness (directivity) compared to low-frequency band electromagnetic waves. Therefore, for example, when using a communication device indoors, even if sufficient reception intensity can be ensured near a window where the base station has a clear view, sufficient reception intensity may not be ensured behind an obstacle. Therefore, it is required to bend high-frequency band electromagnetic waves in a specific direction to improve the electromagnetic wave transmission and reception environment.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide an electromagnetic wave deflection sheet capable of realizing a function of deflecting high-frequency band electromagnetic waves in a specific direction with a simple configuration, and a method for manufacturing an electromagnetic wave deflection sheet capable of efficiently manufacturing such an electromagnetic wave deflection sheet.

Means for Solving the Problems

[0006] These objectives are achieved by the present invention as described in (1) to (12) below. (1) An electromagnetic wave deflection sheet that deflects the transmission direction of electromagnetic waves incident on the main surface with respect to the incident direction, Multiple first parts including a first resin material, Multiple second parts with relative permittivity different from that of the first part, It has, An electromagnetic wave deflection sheet characterized in that the first portion and the second portion are aligned in a first direction within the main surface.

[0007] (2) The electromagnetic wave deflection sheet described in (1) above, wherein the difference in relative permittivity between the first part and the second part is 0.1 or more.

[0008] (3) The electromagnetic wave deflection sheet according to (1) or (2) above, wherein the plurality of first parts and the plurality of second parts are arranged alternately in the first direction.

[0009] (4) The electromagnetic wave deflection sheet according to (3) above, wherein the plurality of first portions and the plurality of second portions are arranged alternately in both the first direction and the second direction intersecting the first direction within the main plane.

[0010] (5) The electromagnetic wave deflection sheet according to (1) or (2) above, wherein the width of the second portion in the first direction is less than the wavelength of the electromagnetic wave.

[0011] (6) The second part is an electromagnetic wave deflection sheet according to any one of (1) to (5) above, comprising a second resin material.

[0012] (7) The electromagnetic wave deflection sheet according to (6) above, wherein at least one of the first portion and the second portion contains inorganic particles.

[0013] (8) An electromagnetic wave deflection sheet according to any one of (1) to (7) above, wherein the frequency of the electromagnetic wave is 1 GHz or more and 300 GHz or less.

[0014] (9) An electromagnetic wave deflection layer including the first portion and the second portion, A support substrate that supports the electromagnetic wave deflection layer, An electromagnetic wave deflection sheet according to any of (1) to (8) above, comprising the above.

[0015] (10) An electromagnetic wave deflection sheet according to any one of (1) to (9) above, which is used by being attached to a transparent area of ​​a building in which the transmission of electromagnetic waves is permitted.

[0016] (11) A method for manufacturing an electromagnetic wave deflection sheet that deflects the transmission direction of electromagnetic waves incident on the main surface with respect to the incident direction, A step of forming a first coating film by discharging a first ink containing a first resin material so that it is periodically arranged in a first direction within the main surface, and a step of forming a second coating film by discharging a second ink containing a second resin material, A step of drying the first coating film and the second coating film to obtain a first portion and a second portion having a dielectric constant different from that of the first portion, A method for manufacturing an electromagnetic wave deflection sheet, characterized by having the following features.

[0017] (12) A method for manufacturing an electromagnetic wave deflection sheet that deflects the transmission direction of electromagnetic waves incident on the main surface with respect to the incident direction, A process of forming a photosensitive film on a substrate for film formation, The process involves performing pattern exposure on the photosensitive film in which exposed and unexposed regions are periodically arranged, thereby creating a difference in relative permittivity in the photosensitive film, and forming a first region and a second region having a relative permittivity different from that of the first region. A method for manufacturing an electromagnetic wave deflection sheet, characterized by having the following features. [Effects of the Invention]

[0018] According to the present invention, an electromagnetic wave deflection sheet can be obtained that can realize the function of deflecting high-frequency electromagnetic waves in a specific direction with a simple configuration. Furthermore, according to the present invention, the above-mentioned electromagnetic wave deflection sheet can be manufactured efficiently.

Brief Description of the Drawings

[0019] [Figure 1] It is a plan view showing an electromagnetic wave deflection sheet according to the first embodiment. [Figure 2] It is a partial cross-sectional view showing a part of the cross-section taken along the line A-A in FIG. 1. [Figure 3] It is a process diagram for explaining a method of manufacturing an electromagnetic wave deflection sheet according to the first embodiment. [Figure 4] It is a conceptual diagram for explaining a method of manufacturing the electromagnetic wave deflection sheet shown in FIG. 3. [Figure 5] It is a process diagram for explaining a method of manufacturing an electromagnetic wave deflection sheet according to a modified example. [Figure 6] It is a conceptual diagram for explaining a method of manufacturing the electromagnetic wave deflection sheet shown in FIG. 5. [Figure 7] It is a plan view showing an electromagnetic wave deflection sheet according to the second embodiment. [Figure 8] It is a plan view showing an electromagnetic wave deflection sheet according to the third embodiment. [Figure 9] It is a cross-sectional view showing an electromagnetic wave deflection sheet according to the third embodiment. [Figure 10] It is a conceptual diagram for explaining a method of measuring the intensity distribution of electromagnetic waves transmitted through a subject. [Figure 11] It is a diagram showing simulation results of the intensity distribution of electromagnetic waves transmitted through the electromagnetic wave deflection sheets of Examples 1 to 7. [Figure 12] It is a diagram showing simulation results of the intensity distribution of electromagnetic waves transmitted through the electromagnetic wave deflection sheets of Examples 8 to 14.

Modes for Carrying Out the Invention

[0020] Hereinafter, the electromagnetic wave deflection sheet and its manufacturing method according to the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

[0021] 1. First Embodiment First, an electromagnetic wave deflection sheet and a method for manufacturing the same according to the first embodiment will be described.

[0022] 1.1. Electromagnetic wave deflection sheet Figure 1 is a plan view showing an electromagnetic wave deflection sheet 1 according to the first embodiment. Figure 2 is a partial cross-sectional view showing a part of the cross-section along line AA in Figure 1. In Figures 1 and 2, the X, Y, and Z axes are defined as three mutually orthogonal axes. Each axis is represented by an arrow, with the tip of the arrow being "positive" and the base of the arrow being "negative". In the following description, for example, "X-axis direction" includes both the positive and negative directions of the X axis. The same applies to the Y-axis and Z-axis directions. Also, the scale of each component in some of the figures of this application may differ from the actual scale.

[0023] The electromagnetic wave deflection sheet 1 shown in Figure 1 allows electromagnetic waves to pass through in a direction different from the incident direction when transmitted in the thickness direction. In other words, it can deflect the transmission direction of incident electromagnetic waves relative to the incident direction. This makes it possible to radiate even high-frequency electromagnetic waves, which have high directivity, towards locations where the electromagnetic wave source cannot be directly seen. As a result, sufficient reception strength can be ensured even in the shadow of a building where the base station cannot be seen, for example.

[0024] The electromagnetic wave deflection sheet 1 shown in Figure 1 is a sheet that extends along the XY plane. The two faces of the electromagnetic wave deflection sheet 1 that are opposite each other are called the "main faces". When these main faces are viewed from the Z-axis direction, the electromagnetic wave deflection sheet 1 has two types of materials with different relative permittivity arranged periodically in the first direction D1 (X-axis direction) within the main faces. Specifically, the electromagnetic wave deflection sheet 1 has multiple first parts 11 and multiple second parts 12 whose relative permittivity is different from that of the first parts 11. Here, we will explain using the case where the relative permittivity of the second parts 12 is lower than that of the first parts 11 as an example. The first parts 11 and the second parts 12 are arranged alternately in the first direction D1.

[0025] Furthermore, when the main surface is viewed from the Z-axis direction, the first part 11 and the second part 12 shown in Figure 1 each have a shape with their major axis in the second direction D2 (Y-axis direction) within the main surface. Specifically, the first part 11 and the second part 12 each form an elongated rectangle extending in the second direction D2. Therefore, in the electromagnetic wave deflection sheet 1 shown in Figure 1, the first part 11 and the second part 12 are arranged in a stripe-like pattern.

[0026] With this configuration, a difference can be created between the transmission speed of electromagnetic waves in the first section 11 and the transmission speed of electromagnetic waves in the second section 12, based on the difference in relative permittivity. This speed difference causes a phase shift in the electromagnetic waves passing through each section, resulting in interference in a specific direction (first direction D1). As a result, the electromagnetic waves that have passed through the electromagnetic wave deflection sheet 1 are deflected.

[0027] In this embodiment, multiple first portions 11 and multiple second portions 12 are arranged alternately, but the electromagnetic deflection sheet 1 according to the present invention only needs to have a portion in which at least one first portion 11 and at least one second portion are aligned in the first direction D1.

[0028] In the example shown in Figure 2, when the incident direction of the electromagnetic wave incident on the electromagnetic wave deflection sheet 1 is D3 and the transmitted direction after deflection is D4, the transmitted direction D4 is deflected by a deflection angle θ toward the first direction D1 (X-axis direction) with respect to the incident direction D3. This allows the radiation direction of the electromagnetic wave to be deflected toward the desired direction.

[0029] The electromagnetic wave deflection sheet 1 shown in Figures 1 and 2 has a simple structure and can be attached, for example, to the windows of buildings. Windows are usually installed in openings in the walls of buildings. Openings can be said to be transmission regions where electromagnetic waves are relatively more permeable to the wall and transmission is permitted. By attaching the electromagnetic wave deflection sheet 1 to the window (window glass, etc.) installed in such an opening, the effort required for installation is reduced, and the electromagnetic wave deflection sheet 1 can be placed in a position where its effects can be easily enjoyed without compromising the appearance.

[0030] This allows the electromagnetic wave deflection sheet 1 to deflect electromagnetic waves arriving from an outdoor electromagnetic wave source when they enter the window. As a result, sufficient reception strength can be ensured even when the receiver is placed in the shadow of a wall or other area where the electromagnetic wave source cannot be directly seen.

[0031] Furthermore, the location where the electromagnetic wave deflection sheet 1 is placed is not limited to openings in walls; for example, it may be outdoors. Examples of outdoor locations include rooftops and side walls of buildings and transmission towers, mountaintops and slopes, etc. Such locations offer good visibility and can receive high-intensity electromagnetic waves. Therefore, by placing the electromagnetic wave deflection sheet 1 in such locations, the electromagnetic waves can be deflected towards locations where the electromagnetic wave source cannot be directly seen.

[0032] Alternatively, the locations of the electromagnetic wave source and the receiver may be swapped. In other words, the electromagnetic wave source may be installed indoors and the receiver outdoors. Even in this case, sufficient signal strength can be ensured at the receiver.

[0033] The electromagnetic wave deflection sheet 1 is also useful for deflecting high-frequency electromagnetic waves, including the millimeter wave band. High-frequency electromagnetic waves, including the millimeter wave band, are, for example, electromagnetic waves with frequencies from 1 GHz to 300 GHz, preferably from 10 GHz to 100 GHz. Such high-frequency electromagnetic waves are used for high-speed, high-capacity communication, for example, but because they have high directivity, transmission and reception may become unstable in places where the electromagnetic wave source cannot be directly seen. In such cases, technology to deflect electromagnetic waves is required. By using the electromagnetic wave deflection sheet 1, even high-frequency electromagnetic waves can be efficiently deflected, and for example, the area where high-speed, high-capacity communication is possible can be expanded.

[0034] The electromagnetic wave deflection sheet 1 shown in Figure 1 is composed of two types of parts with different relative permittivity, but it may be composed of three or more types of parts. In other words, the electromagnetic wave deflection sheet 1 may have a third part, a fourth part, ... with different relative permittivity from each other.

[0035] It should be noted that the deflection pattern of electromagnetic waves is not limited to the direction shown in Figure 2. Examples of deflection patterns include diffusion, focusing, and refraction of electromagnetic waves in the first direction D1. Diffusion and refraction of electromagnetic waves allow them to bend towards the first direction D1, as described above, towards locations where the electromagnetic wave source cannot be directly seen, thereby improving the electromagnetic wave transmission and reception environment. Focusing of electromagnetic waves increases the electromagnetic wave intensity at the focal point. This allows electromagnetic waves to reach locations far from windows, for example, or improves the transmission and reception environment at repeaters.

[0036] In this specification, as an example, an electromagnetic wave deflection sheet 1 capable of refracting electromagnetic waves will be described. The transmission direction D4 and deflection angle θ shown in Figure 2 can be adjusted according to the wavelength of the electromagnetic wave and other factors, the relative permittivity of each part, the arrangement pattern of the first part 11 and the second part 12 of the electromagnetic wave deflection sheet 1, and the width and pitch of the first part 11 and the second part 12 in the first direction D1. Furthermore, by using simulation software that can calculate the far-field radiation pattern of electromagnetic waves transmitted through the electromagnetic wave deflection sheet 1, the design values ​​necessary to deflect electromagnetic waves of a predetermined wavelength to the desired transmission direction D4 and deflection angle θ can be found.

[0037] Furthermore, the deflection pattern of the electromagnetic waves may be uniform across the entire electromagnetic wave deflection sheet 1, or it may differ in parts. In other words, the arrangement pattern of the first part 11 and the second part 12 shown in Figure 1 may be set across the entire electromagnetic wave deflection sheet 1, or it may be set in only a part of it.

[0038] 1.1.1.First part The first part 11 is made of a first resin material. This allows the first part 11 to be manufactured at low cost. In addition, resins generally have a low specific gravity and tend to have a higher electromagnetic wave transmittance compared to high specific gravity materials. Therefore, by using the first resin material, an electromagnetic wave deflection sheet 1 with suppressed electromagnetic wave attenuation can be obtained. Furthermore, resins are lightweight and generally transparent. For this reason, by using the first resin material, an electromagnetic wave deflection sheet 1 that is lightweight and highly transparent can be obtained.

[0039] The relative permittivity of the first portion 11 is not particularly limited, but is preferably 1.2 or more and 20.0 or less.

[0040] The thickness of the first portion 11 is not particularly limited, but is preferably 3 μm or more and 30.0 mm or less, more preferably 50 μm or more and 20.0 mm or less, even more preferably 100 μm or more and 15.0 mm or less, and particularly preferably 2.0 mm or more and 13.0 mm or less. If the thickness of the first portion 11 is within the above range, it is possible to suppress electromagnetic wave transmission loss while achieving both mechanical strength and flexibility of the first portion 11.

[0041] Furthermore, if the thickness of the first portion 11 falls below the lower limit, the mechanical strength of the electromagnetic wave deflection sheet 1 may decrease. On the other hand, if the thickness of the first portion 11 exceeds the upper limit, the attenuation of electromagnetic waves passing through the electromagnetic wave deflection sheet 1 may increase, or the flexibility of the electromagnetic wave deflection sheet 1 may decrease.

[0042] The width W11 of the first portion 11 in the first direction D1 is not particularly limited, but is preferably less than the wavelength λ of the incident electromagnetic wave, more preferably 0.1λ or more and 0.9λ or less, even more preferably 0.3λ or more and 0.8λ or less, and particularly preferably 0.4λ or more and 0.7λ or less. This allows for efficient deflection of electromagnetic waves. In other words, an electromagnetic wave deflection sheet 1 with low attenuation associated with deflection is obtained.

[0043] For example, if the wavelength λ of the electromagnetic wave is 10.7 mm (the frequency of the electromagnetic wave is 28 GHz), the width W11 is preferably less than 10.7 mm, and more preferably between 1.07 mm and 9.63 mm.

[0044] The length L11 of the first portion 11 in the second direction D2 is not particularly limited, but is set appropriately according to the width W11. The ratio L11 / W11 of length L11 to width W11 is preferably 1.0 or more, more preferably 2.0 or more, even more preferably 3.0 or more, and particularly preferably 10.0 or more. This makes it possible to realize an electromagnetic wave deflection sheet 1 that easily deflects electromagnetic waves in the first direction D1.

[0045] The upper limit of the ratio L11 / W11 is not particularly limited, but it is preferably 100 or less, and more preferably 50 or less.

[0046] Furthermore, the ratio L11 / W11 may be equal to each other in all first parts 11, or they may be different from each other, or there may be a mixture of equal and different parts.

[0047] Examples of the first resin material include thermosetting resins, thermoplastic resins, and synthetic rubber.

[0048] Examples of thermosetting resins include silicone resins, urethane resins, melamine resins, epoxy resins, phenolic resins, and urea resins.

[0049] Examples of thermoplastic resins include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, olefin resins such as polyethylene, polypropylene, and cycloolefin polymers, (meth)acrylic resins such as polymethyl methacrylate, polycarbonate resins, polystyrene, polyvinyl chloride, vinyl polymers, polyamides, acrylonitrile-butadiene-styrene copolymer resins (ABS resins), acrylonitrile-ethylene-propylene-diene-styrene copolymer resins (AES resins), and thermoplastic elastomers.

[0050] Examples of synthetic rubbers include ethylene-propylene-diene rubber (EPDM), acrylonitrile-butadiene rubber (NBR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), silicone rubber, and urethane rubber.

[0051] The content of the first resin material in the first part 11 is not particularly limited, but is preferably 30% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more.

[0052] Furthermore, the first part 11 may contain two or more of the above-mentioned resins, or it may contain both the above-mentioned resins and other resins.

[0053] Furthermore, the first part 11 may contain any additives. Examples of additives include inorganic particles, organic particles, colorants, etc.

[0054] Examples of inorganic particles include metal particles, ceramic particles, and glass particles. By using inorganic particles, the dielectric constant of the first part 11 can be increased. Furthermore, by using inorganic particles, the first resin material can be selected based on other physical properties without considering the dielectric constant of the first resin material itself.

[0055] Among inorganic particles, ceramic particles are preferably used. Ceramic particles have a high relative permittivity and a low dielectric loss tangent. Therefore, they can deflect electromagnetic waves more efficiently and suppress electromagnetic wave transmission loss.

[0056] Examples of ceramic materials that constitute ceramic particles include barium titanate, barium zirconate titanate, strontium titanate, calcium titanate, bismuth titanate, magnesium titanate, barium neodymium titanate, barium tin titanate, barium magnesium niobate, barium magnesium tantalate, lead titanate, lead zirconate, lead zirconate titanate, lead niobate, lead magnesium niobate, lead nickel niobate, lead tungstate, calcium tungstate, and lead magnesium tungstate. One or more of these materials, or mixtures of two or more, are used.

[0057] The average particle size of the inorganic particles is not particularly limited, but is preferably between 4 nm and 1000 nm, and more preferably between 50 nm and 500 nm. This improves the dispersibility and packing properties of the inorganic particles.

[0058] The average particle size of inorganic particles is defined as the particle size at which the cumulative frequency of the smaller diameter side is 50% in the volume-based particle size distribution obtained using a laser diffraction type particle size distribution analyzer.

[0059] The content of inorganic particles in the first part 11 can be set appropriately according to the target relative permittivity and is not particularly limited, but as an example, it is preferably 0.5 volume% to 80 volume%, and more preferably 1 volume% to 60 volume%. This makes it possible to adjust the relative permittivity in the first part 11 to the target value and suppress the deterioration of the mechanical properties of the first part 11.

[0060] 1.1.2.Second part The second part 12 shown in Figure 1 is made of a second resin material. This allows the second part 12 to be manufactured at low cost. Furthermore, resins generally have a low specific gravity and tend to have a higher electromagnetic wave transmittance compared to high specific gravity materials. Therefore, by using the second resin material, an electromagnetic wave deflection sheet 1 with suppressed electromagnetic wave attenuation can be obtained. In addition, resins are lightweight and generally transparent. For this reason, by using the second resin material, an electromagnetic wave deflection sheet 1 that is lightweight and highly transparent can be obtained.

[0061] The constituent material of the second part 12 is not limited to the above, and may be other materials, such as voids. However, from the viewpoint of ensuring the smoothness and mechanical strength of the surface of the electromagnetic wave deflection sheet 1, the constituent material of the second part 12 is preferably the second resin material.

[0062] In this embodiment, as an example, the relative permittivity of the second portion 12 is set to be lower than that of the first portion 11. The difference between the relative permittivity of the first portion 11 and the second portion 12 should be greater than 0, and preferably 0.1 or more.

[0063] The thickness of the second part 12 is not particularly limited, but is preferably 3 μm or more and 30.0 mm or less, more preferably 50 μm or more and 20.0 mm or less, even more preferably 100 μm or more and 15.0 mm or less, and particularly preferably 2.0 mm or more and 13.0 mm or less. If the thickness of the second part 12 is within the above range, it is possible to suppress electromagnetic wave transmission loss while achieving both mechanical strength and flexibility of the second part 12.

[0064] Furthermore, if the thickness of the second portion 12 falls below the lower limit, the mechanical strength of the electromagnetic wave deflection sheet 1 may decrease. On the other hand, if the thickness of the second portion 12 exceeds the upper limit, the attenuation of electromagnetic waves passing through the electromagnetic wave deflection sheet 1 may increase, or the flexibility of the electromagnetic wave deflection sheet 1 may decrease.

[0065] The width W12 of the second portion 12 in the first direction D1 is preferably less than the wavelength λ of the incident electromagnetic wave, more preferably 0.1λ to 0.9λ, even more preferably 0.3λ to 0.8λ, and particularly preferably 0.4λ to 0.7λ. This allows for efficient deflection of electromagnetic waves. In other words, an electromagnetic wave deflection sheet 1 with low attenuation associated with deflection is obtained.

[0066] The length L12 of the second portion 12 in the second direction D2 is not particularly limited, but is set appropriately according to the width W12. The ratio L12 / W12 of length L12 to width W12 is preferably 1.0 or more, more preferably 2.0 or more, even more preferably 3.0 or more, and particularly preferably 10.0 or more. This makes it possible to realize an electromagnetic wave deflection sheet 1 that is particularly easy to deflect in the first direction D1.

[0067] The upper limit of the ratio L12 / W12 is not particularly limited, but it is preferably 100 or less, and more preferably 50 or less.

[0068] Furthermore, the ratio L12 / W12 may be equal to each other in all second parts 12, or they may be different from each other, or there may be a mixture of equal and different parts.

[0069] Examples of the second resin material include thermosetting resins, thermoplastic resins, and synthetic rubber. The materials listed above as the first resin material are also included as the second resin material.

[0070] The content of the second resin material in the second part 12 is not particularly limited, but is preferably 30% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more.

[0071] Furthermore, the second part 12 may contain two or more of the above-mentioned resins, or it may contain both the above-mentioned resins and other resins.

[0072] Furthermore, the second part 12 may contain any additives. Examples of additives include inorganic particles, organic particles, colorants, etc.

[0073] Among these, inorganic particles include those similar to those described in the first section 11 above. In general, inorganic particles act to increase the relative permittivity. Therefore, the section with the higher relative permittivity between the first section 11 and the second section 12 may contain inorganic particles. This makes it possible to create a relative permittivity difference relatively easily, regardless of whether it is the first or second resin material.

[0074] The content of inorganic particles in the second part 12 can be set appropriately according to the target relative permittivity and is not particularly limited, but as an example, it is preferably 0.5 volume% to 80 volume%, and more preferably 1 volume% to 60 volume%. This makes it possible to adjust the relative permittivity in the second part 12 to the target value and suppress the deterioration of the mechanical properties of the second part 12.

[0075] 1.1.3.Characteristics The deflection angle θ is controlled based on, for example, the frequency of the electromagnetic wave, the width W11 and length L11 of the first section 11, the width W12 and length L12 of the second section 12, the difference in relative permittivity, and the thickness of the first section 11 and the second section 12. In particular, the ratio of width W11 to width W12 tends to contribute to the deflection angle θ. Simulation software can be used to determine these parameters. By using simulation software, each parameter necessary to achieve the desired deflection angle θ can be easily determined. The simulation software used is one that can calculate the far-field radiation pattern of electromagnetic waves transmitted through the electromagnetic wave deflection sheet 1. This allows the directivity of the deflected electromagnetic wave to be determined, and the angle between the direction of propagation and the incident direction of the electromagnetic wave with the highest intensity (excluding straight-traveling electromagnetic waves) can be determined as the deflection angle θ.

[0076] The deflection angle θ is set according to the purpose, but as an example, it is preferably greater than 0° and 80° or less, more preferably 15° to 70° or less, and even more preferably 30° to 60° or less. This allows, for example, when the electromagnetic wave deflection sheet 1 is installed, electromagnetic waves to be radiated towards a relatively wide area that is in the shadow of the wall. As a result, the area in which sufficient reception strength can be obtained can be expanded more reliably.

[0077] 1.2. Method for manufacturing electromagnetic wave deflection sheets Figure 3 is a process diagram illustrating the manufacturing method of the electromagnetic wave deflection sheet according to the first embodiment. Figure 4 is a conceptual diagram illustrating the manufacturing method of the electromagnetic wave deflection sheet shown in Figure 3. In Figure 4, the X, Y, and Z axes are defined as three mutually orthogonal axes. The manufacturing method shown in Figure 3 comprises a coating film formation step S102 and a drying step S104.

[0078] 1.2.1.Coating film formation process In the coating formation process S102, first, a film-forming substrate 5 is prepared. The film-forming substrate 5 has a surface 51 and is used to form the electromagnetic wave deflection sheet 1 shown in Figure 2. Preferably, the surface 51 of the film-forming substrate 5 is treated with a release agent. This allows the formed electromagnetic wave deflection sheet 1 to be easily peeled off the film-forming substrate 5. The film-forming substrate 5 also functions as a protective layer to protect the surface of the electromagnetic wave deflection sheet 1. When attaching the electromagnetic wave deflection sheet 1 to a window or the like, peeling off the film-forming substrate 5 immediately before the work can suppress the adhesion of foreign matter to the electromagnetic wave deflection sheet 1 while performing the attachment work.

[0079] The constituent material of the film-forming substrate 5 may be an organic material or an inorganic material. Various resin materials are preferably used as the organic material. This makes it possible to obtain a film-forming substrate 5 that is inexpensive and has excellent flexibility.

[0080] The release treatment is a process that allows the formed electromagnetic wave deflection sheet 1 to be easily peeled off. Examples of release treatments include applying a release agent.

[0081] Next, as shown in Figure 4(a), the first ink 61 and the second ink 62 are ejected onto the surface 51 of the film-forming substrate 5. This results in the first coating film 71 and the second coating film 72, as shown in Figure 4(b). The first coating film 71 and the second coating film 72 are formed in a stripe-like arrangement pattern (a pattern in which the first coating film 71 and the second coating film 72 are periodically arranged in the first direction D1 within the surface 51) according to the position and shape of the first part 11 and the second part 12 shown in Figure 2. The ejection of the first ink 61 and the second ink 62 may be performed simultaneously or with a time difference.

[0082] The ejection of the first ink 61 and the second ink 62 can be performed, for example, using a spray head, a dispenser, or the like, in addition to the inkjet head 60 shown in Figure 4(a). Of these, the inkjet method using the inkjet head 60 is preferred. The inkjet method allows for the efficient formation of the first coating film 71 and the second coating film 72 with high positional and shape accuracy.

[0083] The first ink 61 is a liquid material containing the constituent materials or precursors of the first part 11, and is prepared in a state that allows for dispensing. In addition to the constituent materials of the first part 11, the first ink 61 may also contain a solvent or dispersion medium such as water or an organic solvent, various additives, etc.

[0084] The second ink 62 is also a liquid material containing the constituent materials or precursors of the second part 12, and is prepared in a state that can be dispensed. In addition to the constituent materials of the second part 12, the second ink 62 may contain a solvent or dispersion medium such as water or an organic solvent, various additives, etc.

[0085] The above precursor may be a curable monomer. The first ink 61 and the second ink 62 containing the curable monomer become curable inks. The curable ink before curing has good fluidity, and the curable ink after curing has good adhesion and dimensional stability. Therefore, the curable ink contributes to the formation of the first part 11 and the second part 12 with high positional and dimensional accuracy. The curable ink may also be thermosetting or photocurable. In the latter case, the first part 11 and the second part 12 with particularly high positional and dimensional accuracy can be formed.

[0086] Examples of the additives mentioned above include polymerization initiators, surfactants, viscosity modifiers, antioxidants, antistatic agents, UV absorbers, and dispersants.

[0087] 1.2.2.Drying process In drying step S104, the first coating film 71 and the second coating film 72 are dried. This yields the first part 11 and the second part 12 shown in Figure 2.

[0088] The first coating film 71 and the second coating film 72 may be dried naturally or by forced drying. Forced drying may involve heating, reduced pressure, gas spraying, etc.

[0089] Furthermore, if the first coating film 71 and the second coating film 72 are curable, a curing treatment may be performed in the drying step S104. The curing treatment is a treatment that causes a curing reaction in the curable monomer and includes, for example, heat treatment, light irradiation treatment, ultraviolet irradiation treatment, etc.

[0090] As described above, the electromagnetic wave deflection sheet 1 shown in Figure 1 can be manufactured efficiently. Afterward, the obtained electromagnetic wave deflection sheet 1 is peeled off the film deposition substrate 5. This allows for efficient manufacturing even when the electromagnetic wave deflection sheet 1 is thin.

[0091] 2. Variations of the manufacturing method Next, a method for manufacturing an electromagnetic wave deflection sheet according to a modified example will be described.

[0092] Figure 5 is a process diagram illustrating a modified version of the electromagnetic wave deflection sheet manufacturing method. Figure 6 is a conceptual diagram illustrating the manufacturing method of the electromagnetic wave deflection sheet shown in Figure 5. In Figure 6, the X, Y, and Z axes are defined as three mutually orthogonal axes.

[0093] The following describes modified examples, focusing on the differences from the first embodiment, and omitting explanations of similar aspects. In Figure 6, components similar to those in the first embodiment are denoted by the same reference numerals.

[0094] The manufacturing method shown in Figure 5 comprises a photosensitive film formation step S202 and an exposure step S204.

[0095] 2.1. Photosensitive film formation process In the photosensitive film formation step S202, as shown in Figure 6(a), a photosensitive film 75 is formed on the surface 51 of the film-forming substrate 5. The photosensitive film 75 is a film that has photosensitivity, where the relative permittivity changes with exposure. By appropriately setting the exposure area, it is possible to form areas with differences in relative permittivity.

[0096] To achieve the above photosensitivity, organic compounds whose molecular structure changes upon exposure are used. Examples of such organic compounds include compounds whose bonds are broken and some of their structure is eliminated upon exposure, and compounds that undergo dimerization reactions, crosslinking reactions, etc., upon irradiation with light. Changes in molecular structure due to such reactions result in a change in relative permittivity, such as an increase or decrease in relative permittivity. This makes it possible to create a difference in relative permittivity between the exposed region 762 and the unexposed region 764.

[0097] 2.2. Exposure Process In the exposure process S204, as shown in Figure 6(b), a pattern exposure is performed on the photosensitive film 75 in which exposed areas 762 and unexposed areas 764 are periodically arranged. When manufacturing the electromagnetic wave deflection sheet 1 shown in Figure 1, exposure is performed in a stripe-shaped arrangement pattern. This makes it possible to create a difference in relative permittivity between the exposed areas 762 and the unexposed areas 764. In Figure 6(b), as an example, the photosensitive film 75 is configured such that the relative permittivity decreases with exposure. In this case, the exposed areas 762 become the second area 12, and the unexposed areas 764 become the first area 11. This results in the electromagnetic wave deflection sheet 1 shown in Figure 6(c).

[0098] For pattern exposure, the exposure mask 766 shown in Figure 6 can be used. Alternatively, maskless exposure may be used instead of mask exposure using the exposure mask 766. The same effects as those of the first embodiment can be obtained in the modified examples described above.

[0099] 3. Second Embodiment Next, an electromagnetic wave deflection sheet and a method for manufacturing the same according to the second embodiment will be described.

[0100] Figure 7 is a plan view showing the electromagnetic wave deflection sheet 1 according to the second embodiment. In Figure 7, the X, Y, and Z axes are defined as three mutually orthogonal axes.

[0101] The second embodiment will be described below, focusing on the differences from the first embodiment, and similar matters will be omitted from the description. In Figure 7, components similar to those in the first embodiment are denoted by the same reference numerals.

[0102] The electromagnetic wave deflection sheet 1 shown in Figure 7 is the same as the electromagnetic wave deflection sheet 1 shown in Figure 1, except that the arrangement pattern of the first part 11 and the second part 12 is different.

[0103] In the first embodiment described above, the first portion 11 and the second portion 12, which are elongated rectangles extending in the Y-axis direction, are arranged in a striped pattern, alternating in the first direction D1 (X-axis direction). In this embodiment as well, as an example, the relative permittivity of the second portion 12 is set to be lower than that of the first portion 11.

[0104] In contrast, in this embodiment, the granular second portion 12 is arranged in both the first direction D1 (X-axis direction) and the second direction D2 intersecting it, with the first portion 11 in between. In other words, in this embodiment, the granular second portion 12 is dispersed within the first portion 11 at predetermined intervals. Therefore, the electromagnetic wave deflection sheet 1 shown in Figure 7 has an arrangement pattern in which dot-shaped second portions 12 are dispersed within the first portion 11. As a result, the first portion 11 and the second portion 12 are arranged alternately in both the first direction D1 and the second direction D2 intersecting it within the main plane.

[0105] In the example shown in Figure 7, the second direction D2 is a direction that intersects both the X-axis and Y-axis directions within the main plane. With a configuration in which the first part 11 and the second part 12 are arranged alternately in both the first direction D1 and the second direction D2, electromagnetic waves passing through the electromagnetic wave deflection sheet 1 are deflected not only in the first direction D1 (X-axis direction) but also in the second direction D2.

[0106] When such an electromagnetic wave deflection sheet 1 is attached to a window, for example, it not only deflects the electromagnetic waves to the side at the same height as the incident point, but also deflects them upward and downward from the incident point. As a result, the area over which electromagnetic waves are emitted can be expanded.

[0107] The second part 12 shown in Figure 7 is a perfect circle in plan view, but this shape is not particularly limited. Examples of plan view shapes of the second part 12 include ellipses, ovals, triangles, squares, pentagons, hexagons, octagons, and other shapes.

[0108] The width W12 of the second part 12 in the first direction D1 and the length L12 of the second part 12 in the second direction D2 are not particularly limited.

[0109] A method for manufacturing the electromagnetic wave deflection sheet 1 according to the second embodiment can be, for example, the same method as the method for manufacturing the electromagnetic wave deflection sheet according to the first embodiment or a modified version thereof. In the second embodiment described above, the same effects as in the first embodiment can be obtained.

[0110] 4. Third Embodiment Next, an electromagnetic wave deflection sheet and a method for manufacturing the same according to the third embodiment will be described.

[0111] Figure 8 is a plan view showing the electromagnetic wave deflection sheet 1 according to the third embodiment. In Figure 8, the X, Y, and Z axes are defined as three mutually orthogonal axes.

[0112] The third embodiment will be described below, focusing on the differences from the first or second embodiment, and omitting explanations of similar matters. In Figure 8, components similar to those in the first and second embodiments are denoted by the same reference numerals.

[0113] The electromagnetic wave deflection sheets 1 shown in Figures 8(a) to 8(g) are modified arrangement patterns of the first portion 11 and the second portion 12. Each of the electromagnetic wave deflection sheets 1 shown in Figures 8(a) to 8(g) has at least the first portion 11 and the second portion 12, and is the same as the first or second embodiment except for the difference in their arrangement patterns.

[0114] The electromagnetic wave deflection sheet 1 shown in Figure 8(a) is the same as the electromagnetic wave deflection sheet 1 according to the first embodiment, except that the second portion 12 does not extend to the outer edge. Specifically, multiple second portions 12 are arranged in the central part in the X-axis direction and the central part in the Y-axis direction. Each of the multiple second portions 12 has a rectangular shape extending in the second direction D2 and is arranged in the first direction D1. The pitch of the second portions 12 may be different from each other, but in Figure 8(a), they are set to be equal. The first portion 11 and the second portion 12 have different relative permittivity. That is, the relative permittivity of the second portion 12 may be higher or lower than that of the first portion 11.

[0115] In the electromagnetic wave deflection sheet 1 shown in Figure 8(a), for example, by adjusting the relative permittivity of each part, the width and pitch of each part of the second part 12 in the first direction D1, etc., according to the wavelength of the electromagnetic wave and other factors, diffusion, focusing, refraction, etc. of the electromagnetic wave in the first direction D1 can be achieved.

[0116] The electromagnetic wave deflection sheet 1 shown in Figure 8(b) is the same as the electromagnetic wave deflection sheet 1 shown in Figure 8(a), except that the arrangement pattern of the second portion 12 in the first direction D1 is different. In Figure 8(b), the direction from the center of the electromagnetic wave deflection sheet 1 toward the outer edge (radial direction) is defined as the first direction D1. In the arrangement pattern of the second portion 12 shown in Figure 8(b), the pitch between the second portion 12 changes so that it gradually widens in the first direction D1. The relative permittivity of the second portion 12 may be higher or lower than that of the first portion 11.

[0117] In the electromagnetic wave deflection sheet 1 shown in Figure 8(b), for example, by adjusting the relative permittivity of each part, the width and pitch of each part of the second part 12 in the first direction D1, etc., according to the wavelength of the electromagnetic wave and other factors, diffusion, focusing, refraction, etc. of the electromagnetic wave in the first direction D1 can be achieved.

[0118] The electromagnetic wave deflection sheet 1 shown in Figure 8(c) is the same as the electromagnetic wave deflection sheet 1 shown in Figure 8(b), except that a portion of the second section 12 is replaced by the third section 13 or the fourth section 14. Specifically, in Figure 8(c), of the five second sections 12 shown in Figure 8(b), all but the second section 12 located in the center in the X-axis direction are replaced by the third section 13 or the fourth section 14. As a result, in the first direction D1, the second section 12, the third section 13, and the fourth section 14 are aligned with the first section 11 in between. When the relative permittivity of the first part 11, the second part 12, the third part 13, and the fourth part 14 are εr1, εr2, εr3, and εr4, the electromagnetic wave deflection sheet 1 may satisfy εr1 < εr2 < εr3 < εr4, or εr4 < εr3 < εr2 < εr1, or any other inequality relationship.

[0119] In the electromagnetic wave deflection sheet 1 shown in Figure 8(c), for example, by adjusting the relative permittivity of each part, the width and pitch of the second part 12, third part 13, and fourth part 14 in the first direction D1, etc., according to the wavelength of the electromagnetic wave and other factors, diffusion, focusing, refraction, etc. of the electromagnetic wave in the first direction D1 can be achieved.

[0120] The electromagnetic wave deflection sheet 1 shown in Figure 8(d) is the same as the electromagnetic wave deflection sheet 1 according to the second embodiment, except that the relative permittivity of the first portion 11 and the second portion 12 are different. Specifically, in Figure 8(d), dot-shaped second portions 12 with a higher relative permittivity than the first portion 11 are dispersed within the first portion 11.

[0121] In the electromagnetic wave deflection sheet 1 shown in Figure 8(d), for example, by adjusting the relative permittivity of each part, the width and pitch of the second part 12 in the first direction D1 and the second direction D2, etc., according to the wavelength of the electromagnetic wave and other factors, diffusion, focusing, refraction, etc., of the electromagnetic wave in the first direction D1 and the second direction D2 can be achieved.

[0122] The electromagnetic wave deflection sheet 1 shown in Figure 8(e) is the same as the electromagnetic wave deflection sheet 1 shown in Figure 8(d), except that a third section 13 and a fourth section 14 are added, and the arrangement pattern of the second section 12, third section 13, and fourth section 14 in the first direction D1 is different. In Figure 8(e), the direction from the center of the electromagnetic wave deflection sheet 1 toward the outer edge (radial direction) is defined as the first direction D1. Specifically, in Figure 8(e), the second section 12, third section 13, and fourth section 14, each having a dot-like shape and arranged in a ring, are arranged concentrically with the first section 11 in between. As a result, in the first direction D1, the second section 12, third section 13, and fourth section 14 are aligned with the first section 11 in between. When the relative permittivity of the first part 11, the second part 12, the third part 13, and the fourth part 14 are εr1, εr2, εr3, and εr4, the electromagnetic wave deflection sheet 1 may satisfy εr1 < εr2 < εr3 < εr4, or εr4 < εr3 < εr2 < εr1, or any other inequality relationship.

[0123] In the electromagnetic wave deflection sheet 1 shown in Figure 8(e), for example, by adjusting the relative permittivity of each part, the width and pitch of the second part 12, third part 13, and fourth part 14 in the first direction D1, etc., according to the wavelength of the electromagnetic wave and other factors, diffusion, focusing, refraction, etc. of the electromagnetic wave in the first direction D1 can be achieved.

[0124] The electromagnetic wave deflection sheet 1 shown in Figure 8(f) is the same as the electromagnetic wave deflection sheet 1 according to the above embodiment, except that the arrangement pattern of the second portion 12 in the first direction D1 is different. In Figure 8(f), the direction from the center of the electromagnetic wave deflection sheet 1 toward the outer edge (radial direction) is defined as the first direction D1. Specifically, in Figure 8(f), in the first direction D1, a plurality of annular second portions 12 are arranged concentrically, separated by the first portion 11.

[0125] In the electromagnetic wave deflection sheet 1 shown in Figure 8(f), for example, by adjusting the relative permittivity of each part, the width and pitch of each part of the second section 12 in the first direction D1, etc., according to the wavelength of the electromagnetic wave and other factors, diffusion, focusing, refraction, etc. of the electromagnetic wave in the first direction D1 can be achieved.

[0126] The electromagnetic wave deflection sheet 1 shown in Figure 8(g) is the same as the electromagnetic wave deflection sheet 1 shown in Figure 8(f), except that a part of the second part 12 is replaced by the third part 13 or the fourth part 14. Specifically, in Figure 8(g), of the three second parts 12 shown in Figure 8(f), all but the central second part 12 are replaced by the third part 13 or the fourth part 14. As a result, in the first direction D1, the second part 12, the third part 13 and the fourth part 14 are aligned with the first part 11 in between. When the relative permittivity of the first part 11, the second part 12, the third part 13 and the fourth part 14 are εr1, εr2, εr3 and εr4, the electromagnetic wave deflection sheet 1 may satisfy εr1 < εr2 < εr3 < εr4, or εr4 < εr3 < εr2 < εr1, or any other magnitude relationship.

[0127] In the electromagnetic wave deflection sheet 1 shown in Figure 8(g), for example, by adjusting the relative permittivity of each part, the width and pitch of the second part 12, third part 13, and fourth part 14 in the first direction D1, etc., according to the wavelength of the electromagnetic wave and other factors, diffusion, focusing, refraction, etc. of the electromagnetic wave in the first direction D1 can be achieved.

[0128] 5. Fourth Embodiment Next, an electromagnetic wave deflection sheet and a method for manufacturing the same according to the fourth embodiment will be described. Figure 9 is a cross-sectional view showing the electromagnetic wave deflection sheet 1 according to the fourth embodiment.

[0129] The fourth embodiment will now be described, focusing on the differences from the first embodiment, and similar aspects will be omitted. In Figure 9, components similar to those in the first embodiment are denoted by the same reference numerals.

[0130] The electromagnetic wave deflection sheet 1 shown in Figure 9 is the same as the electromagnetic wave deflection sheet 1 shown in Figure 2, except that a support substrate 3 is added.

[0131] The electromagnetic wave deflection sheet 1 shown in Figure 9 comprises a support substrate 3 and an electromagnetic wave deflection layer 10 provided on the surface 31 of the support substrate 3. The electromagnetic wave deflection layer 10 has a first portion 11 and a second portion 12 as shown in Figure 9.

[0132] The support substrate 3 supports the electromagnetic wave deflection layer 10. This ensures the mechanical strength of the electromagnetic wave deflection sheet 1 even when the electromagnetic wave deflection layer 10 is thin. Furthermore, by using the support substrate 3, the electromagnetic wave deflection layer 10 itself does not need to have sufficient mechanical strength. Therefore, the electromagnetic wave deflection sheet 1 can be realized even when the first part 11 and the second part 12 are not sufficiently bonded, or when the second part 12 is not solid (i.e., it is composed of air gaps).

[0133] Examples of materials that make up the support substrate 3 include resin materials and glass materials. Of these, resin materials are preferred from the viewpoint of being lightweight, low cost, and flexible.

[0134] The thickness of the support substrate 3 is not particularly limited, but is preferably 30 μm to 1000 μm, and more preferably 50 μm to 300 μm. This allows sufficient mechanical strength to be provided to the electromagnetic wave deflection sheet 1 while suppressing the attenuation of electromagnetic waves.

[0135] A method for manufacturing the electromagnetic wave deflection sheet 1 according to the fourth embodiment can be, for example, the same method as the method for manufacturing the electromagnetic wave deflection sheet according to the first embodiment or its modified form. In this case, the electromagnetic wave deflection sheet 1 shown in Figure 9 can be manufactured by leaving the film-forming substrate 5 in place without peeling it off. Alternatively, the support substrate 3 may be attached after peeling off the film-forming substrate 5. In the fourth embodiment described above, the same effects as in the first embodiment can be obtained.

[0136] 6. Effects achieved by each of the above embodiments As described above, the electromagnetic wave deflection sheet 1 according to each embodiment is an electromagnetic wave deflection sheet that deflects the transmission direction D4 of electromagnetic waves incident on the main surface with respect to the incident direction D3, and has a plurality of first portions 11 and a plurality of second portions 12. The first portions 11 include a first resin material. The second portions 12 have a relative permittivity different from that of the first portions 11. The first portions 11 and the second portions 12 include a portion aligned in a first direction D1 within the main surface.

[0137] With this configuration, an electromagnetic wave deflection sheet 1 is obtained that can realize the function of deflecting high-frequency electromagnetic waves with a simple configuration. Note that "each embodiment described above" also includes its modified form. The same applies hereafter.

[0138] Furthermore, in the electromagnetic wave deflection sheet 1, the difference in relative permittivity between the first section 11 and the second section 12 is 0.1 or greater.

[0139] With this configuration, the proportion of deflected electromagnetic waves compared to straight-traveling electromagnetic waves can be particularly increased. As a result, an electromagnetic wave deflection sheet 1 with low attenuation can be realized.

[0140] Furthermore, in the electromagnetic wave deflection sheet 1, the multiple first parts 11 and the multiple second parts 12 are arranged alternately in the first direction D1.

[0141] With this configuration, a difference can be created between the transmission speed of electromagnetic waves in the first section 11 and the transmission speed of electromagnetic waves in the second section 12, based on the difference in relative permittivity. This speed difference causes a phase shift in the electromagnetic waves passing through each section, resulting in interference in a specific direction (first direction D1). As a result, the electromagnetic waves that have passed through the electromagnetic wave deflection sheet 1 are deflected.

[0142] Furthermore, in the electromagnetic wave deflection sheet 1, the multiple first parts 11 and the multiple second parts 12 are arranged alternately in both the first direction D1 and the second direction D2 which intersects the first direction D1 within the main plane.

[0143] With this configuration, for example, when attached to a window, it is possible to realize an electromagnetic wave deflection sheet 1 that can deflect electromagnetic waves not only to the side at the same height as the incident position, but also upward and downward from the incident position.

[0144] Furthermore, in the electromagnetic wave deflection sheet 1, the width W12 of the second portion 12 in the first direction D1 is less than the wavelength of the electromagnetic wave.

[0145] With this configuration, an electromagnetic wave deflection sheet 1 capable of efficiently deflecting electromagnetic waves can be obtained.

[0146] Furthermore, in the electromagnetic wave deflection sheet 1, the second portion 12 includes a second resin material. With this configuration, the smoothness and mechanical strength of the surface of the electromagnetic wave deflection sheet 1 can be ensured.

[0147] Furthermore, in the electromagnetic wave deflection sheet 1, at least one of the first and second parts contains inorganic particles.

[0148] With this configuration, for example, inorganic particles act in a direction that increases the relative permittivity, making it possible to form a relative permittivity difference relatively easily, regardless of whether it is the first or second resin material.

[0149] Furthermore, in electromagnetic wave deflection sheet 1, the frequency of electromagnetic waves is between 1 GHz and 300 GHz.

[0150] With this configuration, even high-frequency electromagnetic waves can be efficiently deflected, making it possible to realize an electromagnetic wave deflection sheet 1 that can expand the area where high-speed, high-capacity communication is possible.

[0151] Furthermore, the electromagnetic wave deflection sheet 1 comprises an electromagnetic wave deflection layer 10 including a first portion 11 and a second portion 12, and a support substrate 3 that supports the electromagnetic wave deflection layer 10.

[0152] With this configuration, the mechanical strength of the electromagnetic wave deflection sheet 1 can be ensured even if the electromagnetic wave deflection layer 10 is thin. Furthermore, by using the support substrate 3, the electromagnetic wave deflection layer 10 itself does not need to have sufficient mechanical strength. For this reason, the electromagnetic wave deflection sheet 1 can be realized even if the first part 11 and the second part 12 are not sufficiently bonded, or if the second part 12 is not solid (i.e., it is composed of air gaps).

[0153] Furthermore, the electromagnetic wave deflection sheet 1 is used by being attached to a transmission area in a building where the transmission of electromagnetic waves is permitted.

[0154] With this configuration, for example, when electromagnetic waves arriving from an electromagnetic wave source placed outdoors are incident on the transmission area, the electromagnetic wave deflection sheet 1 can deflect the electromagnetic waves. As a result, even if the receiver is placed in the shadow of a wall or other area where the electromagnetic wave source cannot be directly seen, sufficient reception strength can be ensured.

[0155] Furthermore, the methods for manufacturing electromagnetic wave deflection sheets according to each embodiment are methods for manufacturing electromagnetic wave deflection sheets that deflect the transmission direction D4 of electromagnetic waves incident on the main surface with respect to the incident direction D3, and include a coating film forming step S102 and a drying step S104. In the coating film forming step S102, a first ink 61 containing a first resin material is ejected to form a first coating film 71 so as to be periodically arranged in a first direction D1 within the main surface, and a second ink 62 containing a second resin material is ejected to form a second coating film 72. In the drying step S104, the first coating film 71 and the second coating film 72 are dried to obtain a first portion 11 and a second portion 12 having a relative permittivity different from that of the first portion 11.

[0156] With this configuration, an electromagnetic wave deflection sheet 1, which can achieve the function of deflecting high-frequency electromagnetic waves with a simple structure, can be efficiently manufactured.

[0157] Furthermore, the method for manufacturing an electromagnetic wave deflection sheet according to each embodiment is a method for manufacturing an electromagnetic wave deflection sheet that deflects the transmission direction D4 of electromagnetic waves incident on the main surface with respect to the incident direction D3, and comprises a photosensitive film formation step S202 and an exposure step S204. In the photosensitive film formation step S202, a photosensitive film 75 is formed on the film-forming substrate 5. In the exposure step S204, a pattern exposure is performed on the photosensitive film 75 in which an exposed area 762 and an unexposed area 764 are periodically arranged, thereby creating a difference in relative permittivity in the photosensitive film 75 and forming a first area 11 and a second area 12 whose relative permittivity is different from that of the first area 11.

[0158] With this configuration, an electromagnetic wave deflection sheet 1, which can achieve the function of deflecting high-frequency electromagnetic waves with a simple structure, can be efficiently manufactured.

[0159] Although the electromagnetic wave deflection sheet and its manufacturing method of the present invention have been described above, the present invention is not limited to the embodiments described above.

[0160] For example, the electromagnetic wave deflection sheet and its manufacturing method of the present invention may have any configuration added to the above embodiment. An example of an optional configuration is an adhesive layer provided on the main surface of the electromagnetic wave deflection sheet according to the above embodiment. The adhesive layer allows the electromagnetic wave deflection sheet to be easily attached to a window or the like.

[0161] Furthermore, in the method for manufacturing the electromagnetic wave deflection sheet of the present invention, the first and second portions may be formed using photolithography and etching techniques. [Examples]

[0162] Next, specific embodiments of the present invention will be described. However, the present invention is not limited in any way to these embodiments.

[0163] 7. Preparation of the specimen 7.1. Example 1 A coating film was obtained by ejecting a first ink and a second ink onto a PET substrate with a thickness of 100 μm using an inkjet method. Next, the coating film was cured to form the first and second portions of the arrangement pattern shown in Figure 1. This resulted in obtaining the electromagnetic wave deflection sheet of Example 1.

[0164] Next, the electromagnetic wave deflection sheet was peeled off and recovered from the PET substrate. Then, the electromagnetic wave deflection sheet was attached to a frame to create a test subject for evaluation. An aluminum plate with a square outer shape and an inner opening was used for the frame. The outer dimensions were 200 mm x 200 mm, and the inner opening dimensions were 100 mm x 100 mm.

[0165] 7.2. Examples 2-28 and Comparative Examples 1-4 Electromagnetic wave deflection sheets for each example or comparative example were obtained in the same manner as in Example 1, except that the manufacturing conditions for the electromagnetic wave deflection sheets were changed as shown in Table 1 or Table 2. The difference in dielectric constant between the first portion formed with the first ink and the second portion formed with the second ink was adjusted by the composition or content of the resin component and inorganic particles contained in each ink. An acrylic resin emulsion was used as the resin component. Spherical calcium titanate particles were used as the inorganic particles.

[0166] 8. Evaluation of the subjects The following evaluations were performed on the subjects to which the electromagnetic wave deflection sheets of each example and comparative example were attached.

[0167] 8.1. Measurement of Deflection Angle θ Figure 10 is a conceptual diagram illustrating a method for measuring the intensity distribution of electromagnetic waves transmitted through a test subject 150. In the method shown in Figure 10, first, electromagnetic waves (plane waves WA) of the frequencies shown in Table 1 or Table 2 were incident on the test subject 150, which is equipped with an electromagnetic wave deflection sheet 1 and a frame 100. Next, a receiver 20 was placed 200 mm away from the center of the electromagnetic wave deflection sheet 1, and the electromagnetic wave intensity was measured while varying the angle α of the receiver 20 relative to the direction of incidence of the electromagnetic waves from 0° to 90°. Then, the angle α at which the highest electromagnetic wave intensity was measured was defined as the deflection angle θ. The measured deflection angle θ was then evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 1 and 2.

[0168] A: The deflection angle θ is between 30° and 60°. B: The deflection angle θ is 15° or more but less than 30° or greater than 60° and less than or equal to 70°. C: Deflection angle θ is greater than 0° and less than 15° or greater than 70° and less than or equal to 80°. D: No deflection of electromagnetic waves is observed.

[0169] 8.2. Measurement of electromagnetic wave intensity at deflection angle θ The received electromagnetic wave intensity was measured at the deflection angle θ described above. The obtained electromagnetic wave intensity was then evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 1 and 2.

[0170] A: The receiver 20 can receive electromagnetic waves clearly and stably. B: The receiver 20 can clearly receive electromagnetic waves. C: Receiver 20 can receive electromagnetic waves sufficiently, although not clearly. D: Although the receiver 20 can receive electromagnetic waves, the reception strength is not sufficient.

[0171] [Table 1]

[0172] [Table 2]

[0173] Based on the evaluation results shown in Tables 1 and 2, the following can be observed. In each embodiment, electromagnetic waves could be deflected at a deflection angle θ within a good angular range. In each embodiment, it was confirmed that the electromagnetic wave intensity at the deflection angle θ was sufficiently high.

[0174] Furthermore, when the arrangement pattern was made dot-like, it was possible to deflect electromagnetic waves towards multiple radiation points (not shown) that spread along the XY plane in Figure 7.

[0175] Furthermore, although each example and comparative example shown in Tables 1 and 2 uses a support substrate, the same evaluation results were obtained even when the support substrate was omitted.

[0176] 9. Evaluation by simulation Figure 11 shows the simulation results of the intensity distribution of transmitted electromagnetic waves for the electromagnetic wave deflection sheets of Examples 1 to 7. Figure 12 shows the simulation results of the intensity distribution of transmitted electromagnetic waves for the electromagnetic wave deflection sheets of Examples 8 to 14.

[0177] As shown in Figures 11 and 12, the simulation results confirm the existence of a main beam MB with intensity in the incident direction D3, and a secondary beam SB with a deflection angle θ greater than 0° relative to the incident direction D3. Therefore, the simulation results also confirm that the electromagnetic wave deflection sheets in each embodiment can deflect electromagnetic waves in the direction of a predetermined deflection angle θ. Furthermore, in the embodiment in which the configuration of the electromagnetic wave deflection sheet was optimized, the deflection angle θ was within the target range (for example, about 30° to 60°), and the intensity of the deflected electromagnetic wave was stabilized. [Explanation of Symbols]

[0178] 1. Electromagnetic wave deflection sheet 3. Support substrate 5. Substrates for film deposition 10 Electromagnetic wave deflection layer 11 Part 1 12 Part 2 20 receivers 31 Surface 51 Surface 60 inkjet heads 61 First Ink 62 Second Ink 71 First Coating 72 Second Coating 75 Photosensitive coating 100 frame 150 subjects 762 Exposure Area 764 Unexposed area 766 Exposure Mask D1 1st direction D2 2nd direction D3 Incidence direction D4 Transmission direction L11 Length L12 Length MB Main Beam S102 Paint film formation process S104 Drying process S202 Photosensitive film formation process S204 Exposure Process SB sub-beam W11 width W12 width WA plane wave α Elongation θ deflection angle

Claims

1. An electromagnetic wave deflection sheet that deflects the transmission direction of electromagnetic waves incident on its main surface relative to the incident direction, Multiple first parts including a first resin material, Multiple second parts with relative permittivity different from that of the first part, It has, An electromagnetic wave deflection sheet characterized in that the first portion and the second portion are aligned in a first direction within the main surface.

2. The electromagnetic wave deflection sheet according to claim 1, wherein the difference in relative permittivity between the first portion and the second portion is 0.1 or more.

3. The electromagnetic wave deflection sheet according to claim 1 or 2, wherein a plurality of the first portions and a plurality of the second portions are arranged alternately in the first direction.

4. The electromagnetic wave deflection sheet according to claim 3, wherein the plurality of first portions and the plurality of second portions are arranged alternately in both the first direction and the second direction intersecting the first direction within the main surface.

5. The electromagnetic wave deflection sheet according to claim 1 or 2, wherein the width of the second portion in the first direction is less than the wavelength of the electromagnetic wave.

6. The electromagnetic wave deflection sheet according to claim 1 or 2, wherein the second portion comprises a second resin material.

7. The electromagnetic wave deflection sheet according to claim 6, wherein at least one of the first portion and the second portion comprises inorganic particles.

8. The electromagnetic wave deflection sheet according to claim 1 or 2, wherein the frequency of the electromagnetic wave is 1 GHz or more and 300 GHz or less.

9. An electromagnetic wave deflection layer including the first portion and the second portion, A support substrate that supports the electromagnetic wave deflection layer, The electromagnetic wave deflection sheet according to claim 1 or 2, comprising:

10. The electromagnetic wave deflection sheet according to claim 1 or 2, which is used by being attached to a transmission area in a building where the transmission of electromagnetic waves is permitted.

11. A method for manufacturing an electromagnetic wave deflection sheet that deflects the transmission direction of electromagnetic waves incident on its main surface relative to the incident direction, A step of forming a first coating film by discharging a first ink containing a first resin material so that it is periodically arranged in a first direction within the main surface, and a step of forming a second coating film by discharging a second ink containing a second resin material, A step of drying the first coating film and the second coating film to obtain a first portion and a second portion having a dielectric constant different from that of the first portion, A method for manufacturing an electromagnetic wave deflection sheet, characterized by having the following features.

12. A method for manufacturing an electromagnetic wave deflection sheet that deflects the transmission direction of electromagnetic waves incident on its main surface relative to the incident direction, A process of forming a photosensitive film on a substrate for film formation, The process involves performing pattern exposure on the photosensitive film in which exposed and unexposed regions are periodically arranged, thereby creating a difference in relative permittivity in the photosensitive film, and forming a first region and a second region having a relative permittivity different from that of the first region. A method for manufacturing an electromagnetic wave deflection sheet, characterized by having the following features.

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