JP7621406B2 - Exterior structure - Google Patents

Description

This disclosure relates to exterior structures.

Receiving antenna devices are known that are installed on exterior materials such as the roof or exterior wall of a building. For example, Patent Documents 1 and 2 describe incorporating a receiving antenna element into a roof material or exterior wall material.

Japanese Patent Application Publication No. 8-321719 Japanese Unexamined Patent Publication No. 7-193411

An antenna device attached to an exterior material can be used to transmit electromagnetic waves. In general, such antenna devices radiate electromagnetic waves in a spherical shape. However, the energy density of the electromagnetic waves per unit area decreases as the distance from the transmitting antenna device increases. In particular, in recent years, electromagnetic waves have become increasingly higher in frequency in order to carry out high-speed, large-volume information communication. As the frequency of electromagnetic waves increases, the electromagnetic waves tend to travel in a straighter direction and are more susceptible to attenuation. For this reason, there is a demand to increase the strength of the electromagnetic waves.

This disclosure describes an exterior structure that can increase the strength of electromagnetic waves with a simple configuration.

The exterior structure according to one aspect of the present disclosure includes a metal plate, a substrate provided on the metal plate, an antenna element provided on the substrate, and a laminate covering the antenna element. The laminate includes a first dielectric layer covering the antenna element, and a second dielectric layer provided on the first dielectric layer. The dielectric constant of the second dielectric layer is higher than the dielectric constant of the first dielectric layer.

In this exterior structure, the antenna element is covered with a first dielectric layer, and a second dielectric layer having a higher dielectric constant than that of the first dielectric layer is provided on the first dielectric layer. Since the higher the dielectric constant, the higher the refractive index, the refractive index of the second dielectric layer is higher than that of the first dielectric layer. Therefore, the emission angle when the electromagnetic wave radiated from the antenna element is emitted from the boundary between the first dielectric layer and the second dielectric layer is smaller than the incidence angle when the electromagnetic wave is incident on the boundary, so that the electromagnetic wave is refracted toward the stacking direction of the first dielectric layer and the second dielectric layer. This provides directionality. As a result, it is possible to increase the strength of the electromagnetic wave with a simple configuration.

In some embodiments, the laminate may further include a third dielectric layer provided on the second dielectric layer. The dielectric constant of the third dielectric layer may be higher than that of the second dielectric layer. In this case, the refractive index of the third dielectric layer is higher than that of the second dielectric layer. Therefore, the emission angle of the electromagnetic wave when it is emitted from the boundary between the second dielectric layer and the third dielectric layer is smaller than the incidence angle when the electromagnetic wave is incident on the boundary, so that the electromagnetic wave is refracted toward the stacking direction. As a result, the directionality of the electromagnetic wave can be increased, and the intensity of the electromagnetic wave can be further increased.

In some embodiments, the exterior structure may further include an adhesive layer that adheres the substrate to the metal plate. In this case, the substrate on which the antenna element is provided can be fixed to the metal plate without drilling holes in the metal plate. This reduces the possibility of rainwater or the like entering the interior of the building.

In some embodiments, the exterior structure may further include a waterproof membrane that covers the laminate. In this case, the possibility of the antenna element rusting can be reduced, thereby extending the life of the antenna element.

In some embodiments, the exterior structure may further include a roofing material that includes a metal sheet as a surface material. In this case, by using the exterior structure on the roof of a building, an antenna element can be provided on the roof of the building. This makes it possible to efficiently build a communication network.

In some embodiments, the exterior structure may further include an exterior wall material that includes a metal plate as a surface material. In this case, by using the exterior structure on the exterior wall of a building, an antenna element can be provided on the exterior wall of the building. This makes it possible to efficiently build a communication network.

According to each aspect and embodiment of the present disclosure, it is possible to increase the strength of electromagnetic waves with a simple configuration.

FIG. 1 is a plan view showing an exterior structure according to one embodiment. FIG. 2 is a cross-sectional view taken along line II-II of FIG. FIG. 3 is an enlarged perspective view of a portion of FIG. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a diagram for explaining the operating principle of the receiving antenna device shown in FIG. FIG. 6 is a diagram showing the reflection characteristic of the receiving antenna device shown in FIG. FIG. 7 is a diagram showing the reflection characteristics of a receiving antenna device according to a comparative example. FIG. 8 is a diagram for explaining the operating principle of the transmitting antenna device shown in FIG. FIG. 9 is a diagram for explaining electromagnetic waves radiated from the transmitting antenna device shown in FIG. FIG. 10 is a diagram for explaining electromagnetic waves radiated from a transmitting antenna device according to a comparative example. FIG. 11 is an enlarged perspective view of a portion of an exterior structure according to a modified example. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. FIG. 13 is a cross-sectional view showing an exterior structure according to another embodiment. FIG. 14 is a cross-sectional view showing an exterior structure according to still another embodiment. FIG. 15 is a diagram showing an application example of the exterior structure. FIG. 16 is a diagram showing an application example of the exterior structure.

Embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that in the description of the drawings, the same elements are given the same reference numerals, and duplicate descriptions will be omitted.

An exterior structure according to one embodiment will be described with reference to Figures 1 and 2. Figure 1 is a plan view showing an exterior structure according to one embodiment. Figure 2 is a cross-sectional view taken along line II-II in Figure 1. The exterior structure 1 shown in Figures 1 and 2 is a structure used for the exterior of a building. The exterior structure 1 includes an exterior material 10, an antenna device 20, an antenna device 30, an adhesive layer A1 (see Figure 3), and an adhesive layer A2 (see Figure 3).

The exterior material 10 is a finishing material used on the exterior of a building. In this embodiment, the exterior material 10 is a roofing material. The exterior material 10 is a long member that extends in one direction (X-axis direction), and includes a surface material 11 (metal plate), a back surface material 12, and a core material 13.

The surface material 11 is a metal plate material. The surface material 11 is formed by processing a metal plate, for example, by roll forming, press forming, or extrusion forming. Examples of metal plates include color steel plates, copper plates, aluminum plates, titanium plates, stainless steel plates, sandwich steel plates, and clad steel plates.

The surface material 11 includes a decorative surface 11a, a connecting portion 11b, a connecting portion 11c, a folded piece 11d, a plurality of protruding portions 11e, and a protruding piece 11f. The decorative surface 11a is the surface that faces the outside of the building when a building is constructed using the exterior structure 1.

The connecting portion 11b is a portion for connecting the exterior material 10 to another exterior material 10 located above water. The connecting portion 11c is a portion for connecting the exterior material 10 to yet another exterior material 10 located below water. The connecting portion 11b is provided at the above water end of the surface material 11 and extends over the entire length of the surface material 11 in the longitudinal direction. The connecting portion 11c is provided at the below water end of the surface material 11 and extends over the entire length of the surface material 11 in the longitudinal direction. The connecting portion 11b and the connecting portion 11c have shapes that allow them to engage with each other. The connecting portion 11b has, for example, an inverted U-shape in a cross section that intersects with the longitudinal direction (X-axis direction) of the exterior material 10. The connecting portion 11c has, for example, a U-shape in a cross section that intersects with the X-axis direction.

The folded piece 11d is provided on the right end of the surface material 11 and is a portion folded inward (left side) from the right end of the decorative surface 11a. Each protrusion 11e is provided on the decorative surface 11a and protrudes from the decorative surface 11a. The multiple protrusions 11e are arranged at regular intervals in the short direction (Y-axis direction) of the exterior material 10 along the left-right tip of the folded piece 11d. Each protrusion 11e is inclined toward the center of the decorative surface 11a as it moves from above the water to below the water.

The protruding piece 11f is provided at the left end of the surface material 11 and is a portion that protrudes to the left from the decorative surface 11a. The protruding piece 11f is superimposed on the folded piece 11d of the further exterior material 10 located to the left of the exterior material 10 so that the convex portion 11e of the further exterior material 10 is in contact with the back surface of the protruding piece 11f.

The backing material 12 is a sheet-like member. The backing material 12 is obtained by laminating one or more sheets selected from the group consisting of craft paper, aluminum-deposited paper, asphalt felt, thin metal (aluminum, iron, lead, or copper), synthetic resin sheets, rubber sheets, cloth sheets, gypsum paper, aluminum hydroxide paper, and glass fiber nonwoven fabric. The sheets constituting the backing material 12 may be treated to be waterproof and flame-retardant.

The core material 13 is provided between the front material 11 and the back material 12, and is a member that fills the space defined by the front material 11 and the back material 12 without any gaps. The core material 13 can function as a heat insulating material, a reinforcing material, a bulking material, a soundproofing material, a sound absorbing material, a cushioning material, a fireproofing material, and a dew condensation prevention material. For example, a synthetic resin foam is used as the core material 13. Examples of synthetic resin foams include polyurethane foam, polyisocyanurate foam, phenol foam, polyvinyl chloride foam, polyethylene foam, polystyrene foam, and urea foam. The core material 13 is formed, for example, by discharging a mixture obtained by mixing a stock solution of resol-type phenol, a hardener, and a foaming agent onto the back surface of the front material 11 or the back surface of the back material 12, heating it to cause a sufficient reaction, and hardening.

To improve the fire resistance and fire prevention properties of the exterior material 10, the core material 13 may contain various types of flame retardant materials such as lightweight aggregates and fibrous materials. Examples of lightweight aggregates include perlite granules, glass beads, gypsum slag, talc stone, silt balloons, and aluminum hydroxide. Examples of fibrous materials include glass wool, rock wool, carbon fiber, and graphite.

Antenna device 20 is a planar antenna device for receiving. Antenna device 30 is a planar antenna device for transmitting. Antenna device 20 and antenna device 30 are provided on the decorative surface 11a of the surface material 11.

The adhesive layer A1 is a layer that adheres the antenna device 20 to the surface material 11. The adhesive layer A1 is made of, for example, a resin adhesive. An example of the resin adhesive that constitutes the adhesive layer A1 is an epoxy-based adhesive resin. The antenna device 20 is fixed to the surface material 11 by the adhesive layer A1. The length in the Z-axis direction (i.e., the thickness) of the adhesive layer A1 is approximately 1 μm to 500 μm.

The adhesive layer A2 is a layer that adheres the antenna device 30 to the surface material 11. The adhesive layer A2 is made of, for example, a resin adhesive. An example of the resin adhesive that constitutes the adhesive layer A2 is an epoxy-based adhesive resin. The antenna device 30 is fixed to the surface material 11 by the adhesive layer A2. The length in the Z-axis direction (i.e., the thickness) of the adhesive layer A2 is approximately 1 μm to 500 μm.

Next, the structures of the antenna device 20 and the antenna device 30 will be described with reference to Figures 3 and 4. Figure 3 is an enlarged perspective view of a portion of Figure 1. Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3. As shown in Figures 3 and 4, the antenna device 20 includes a substrate 21, an antenna element 22, a laminate 23, a waterproof membrane 24, and a connector 25. The substrate 21, the antenna element 22, the laminate 23, and the waterproof membrane 24 are laminated on the decorative surface 11a in that order in a direction (Z-axis direction) that intersects (for example, perpendicular to) the decorative surface 11a. Note that, for convenience of explanation, the waterproof membrane 24 is omitted from Figure 3.

The substrate 21 is a layer on which the antenna element 22 is placed. The substrate 21 is provided on the surface material 11. Specifically, the substrate 21 is provided on the decorative surface 11a of the surface material 11. The substrate 21 is a rectangular plate material. The length of the substrate 21 in the X-axis direction and the length of the substrate 21 in the Y-axis direction are appropriately set according to the electromagnetic waves to be received. When the electromagnetic waves to be received are radio waves in the 5G (Generation) band or 6G band, the length of the substrate 21 in the X-axis direction and the length of the substrate 21 in the Y-axis direction are, for example, about 6 mm. Until the length (i.e., thickness) of the substrate 21 in the Z-axis direction becomes relatively thick, the thicker the substrate 21 is, the better the effect of preventing mutual interference. From this viewpoint, the thickness of the substrate 21 is, for example, about 100 μm to 500 μm.

The substrate 21 is made of a dielectric. To maintain transmission efficiency and improve weather resistance, polymeric materials such as Teflon (registered trademark), polyamide, polyimide, and polypropylene are used as the dielectric that constitutes the substrate 21. The dielectric tangent of the substrate 21 is, for example, 0.02 or less. The substrate 21 has a front surface 21a and a back surface 21b that intersect with the Z-axis direction. The back surface 21b is a surface that faces the decorative surface 11a via an adhesive layer A1. The front surface 21a is a surface opposite the back surface 21b. The adhesive layer A1 is provided over the entire surface of the back surface 21b. In other words, the adhesive layer A1 is provided between the surface material 11 and the substrate 21.

The antenna element 22 is an element for receiving electromagnetic waves. In this embodiment, the antenna element 22 is a meander line antenna element. The antenna element 22 is provided on the substrate 21. Specifically, the antenna element 22 is provided on the surface 21a of the substrate 21. The antenna element 22 is made of a metal having electrical conductivity. An example of the metal that makes up the antenna element 22 is copper (Cu). The antenna element 22 has a shape according to the type of antenna element 22 and the wavelength of the electromagnetic waves to be received. Examples of the electromagnetic waves to be received include 5G band radio waves and Sub6 band radio waves.

The laminate 23 is a multi-layer structure for drawing electromagnetic waves into the antenna element 22. The laminate 23 covers the entire antenna element 22. The laminate 23 includes a dielectric layer 26, a dielectric layer 27, and a dielectric layer 28. The dielectric layer 26, the dielectric layer 27, and the dielectric layer 28 are laminated on the surface 21a in that order in the Z-axis direction.

The dielectric layer 26 is the bottom layer of the laminate 23. The dielectric layer 26 covers the antenna element 22. The dielectric layer 26 is a rectangular plate material. The dielectric layer 26 has substantially the same outer shape as the substrate 21 in a plan view (as viewed from the Z-axis direction), and is superimposed on the substrate 21 in the Z-axis direction. That is, the dielectric layer 26 covers the entire surface 21a. The length (i.e., thickness) of the dielectric layer 26 in the Z-axis direction is, for example, 20 μm or less. The dielectric constant ε ₁₁ of the dielectric layer 26 is, for example, about 5.0 to 6.0. The dielectric layer 26 is formed of a sheet obtained by kneading, for example, polyester with glass fiber or ceramic powder, which is a high dielectric.

The dielectric layer 27 is an intermediate layer of the laminate 23. The dielectric layer 27 is provided on the dielectric layer 26. The dielectric layer 27 is a rectangular plate material. The dielectric layer 27 has substantially the same outer shape as the substrate 21 and the dielectric layer 26 in a plan view (as viewed from the Z-axis direction), and is superimposed on the dielectric layer 26 in the Z-axis direction. That is, the dielectric layer 27 covers the entire upper surface of the dielectric layer 26. The length (i.e., thickness) of the dielectric layer 27 in the Z-axis direction is, for example, 20 μm or less. The dielectric constant ε ₁₂ of the dielectric layer 27 is lower than the dielectric constant ε ₁₁ , and is, for example, about 2.8 to 3.2. The dielectric layer 27 is, for example, composed of a sheet composed of polyester alone.

The dielectric layer 28 is the uppermost layer of the laminate 23. The dielectric layer 28 is provided on the dielectric layer 27. The dielectric layer 28 is a rectangular plate material. The dielectric layer 28 has substantially the same outer shape as the substrate 21, the dielectric layer 26, and the dielectric layer 27 in a plan view (as viewed from the Z-axis direction), and is superimposed on the dielectric layer 27 in the Z-axis direction. That is, the dielectric layer 28 covers the entire upper surface of the dielectric layer 27. The length (i.e., thickness) of the dielectric layer 28 in the Z-axis direction is, for example, 20 μm or less. The dielectric constant ε ₁₃ of the dielectric layer 28 is lower than the dielectric constant ε ₁₂ , and is, for example, about 2.0 to 2.5. An example of a dielectric material constituting the dielectric layer 28 is Teflon (registered trademark).

The waterproof membrane 24 is a membrane for preventing the intrusion of water. The waterproof membrane 24 covers the substrate 21, the antenna element 22, and the laminate 23. The waterproof membrane 24 is made of a resin that is waterproof and insulating. Examples of resins that make up the waterproof membrane 24 include urethane, FRP (fiber reinforced plastic), and Teflon (registered trademark).

The connector 25 is a member for connecting the antenna element 22 to a power source (not shown). The connector 25 is, for example, a coaxial connector such as an SMA (Sub Miniature Type A) connector. In this embodiment, the connector 25 is provided outside the periphery of the substrate 21 and is connected to an end of the wiring pattern that constitutes the antenna element 22.

3 and 4, the antenna device 30 includes a substrate 31, an antenna element 32, a laminate 33, a waterproof membrane 34, and a connector 35. The substrate 31, the antenna element 32, the laminate 33, and the waterproof membrane 34 are laminated in that order on the decorative surface 11a in a direction (Z-axis direction) intersecting (e.g., perpendicular to) the decorative surface 11a. Note that, for ease of explanation, the waterproof membrane 34 is omitted from FIG. 3.

The substrate 31 is a layer on which the antenna element 32 is placed. The substrate 31 is provided on the surface material 11. Specifically, the substrate 31 is provided on the decorative surface 11a of the surface material 11. The substrate 31 is a rectangular plate material. The length of the substrate 31 in the X-axis direction and the length of the substrate 31 in the Y-axis direction are appropriately set according to the electromagnetic waves to be transmitted. When the electromagnetic waves to be transmitted are 5G band radio waves or 6G band radio waves, the length of the substrate 31 in the X-axis direction and the length of the substrate 31 in the Y-axis direction are, for example, about 6 mm. Until the length of the substrate 31 in the Z-axis direction (i.e., the thickness) becomes thick to a certain extent, the thicker the substrate 31 is, the better the effect of preventing mutual interference. From this viewpoint, the thickness of the substrate 31 is, for example, about 100 μm to 500 μm.

The substrate 31 is made of a dielectric. In order to maintain transmission efficiency and improve weather resistance, polymeric materials such as Teflon (registered trademark), polyamide, polyimide, and polypropylene are used as the dielectric material constituting the substrate 31. The dielectric tangent of the substrate 31 is, for example, 0.02 or less. The substrate 31 has a front surface 31a and a back surface 31b that intersect with the Z-axis direction. The back surface 31b is a surface that faces the decorative surface 11a via an adhesive layer A2. The front surface 31a is a surface opposite to the back surface 31b. The adhesive layer A2 is provided over the entire surface of the back surface 31b. In other words, the adhesive layer A2 is provided between the surface material 11 and the substrate 31.

The antenna element 32 is an element for transmitting electromagnetic waves. In this embodiment, the antenna element 32 is a meander line antenna element. The antenna element 32 is provided on the substrate 31. Specifically, the antenna element 32 is provided on the surface 31a of the substrate 31. The antenna element 32 is made of a metal having electrical conductivity. An example of the metal that constitutes the antenna element 32 is copper (Cu). The antenna element 32 has a shape according to the type of the antenna element 32 and the wavelength of the electromagnetic wave to be transmitted. Examples of the electromagnetic wave to be transmitted include 5G band radio waves and Sub6 band radio waves.

The laminate 33 is a multi-layer structure for forming the directivity of electromagnetic waves. The laminate 33 covers the entire antenna element 32. The laminate 33 includes a dielectric layer 36 (first dielectric layer), a dielectric layer 37 (second dielectric layer), and a dielectric layer 38 (third dielectric layer). The dielectric layer 36, the dielectric layer 37, and the dielectric layer 38 are laminated on the surface 31a in that order in the Z-axis direction.

The dielectric layer 36 is the bottom layer of the laminate 33. The dielectric layer 36 covers the antenna element 32. The dielectric layer 36 is a rectangular plate material. The dielectric layer 36 has substantially the same outer shape as the substrate 31 in a plan view (as viewed from the Z-axis direction), and is superimposed on the substrate 31 in the Z-axis direction. That is, the dielectric layer 36 covers the entire surface 31a. The length (i.e., thickness) of the dielectric layer 36 in the Z-axis direction is, for example, 20 μm or less. The dielectric constant ε ₂₁ of the dielectric layer 36 is, for example, about 2.0 to 2.5. An example of a dielectric material constituting the dielectric layer 36 is Teflon (registered trademark).

The dielectric layer 37 is an intermediate layer of the laminate 33. The dielectric layer 37 is provided on the dielectric layer 36. The dielectric layer 37 is a rectangular plate material. The dielectric layer 37 has substantially the same outer shape as the substrate 31 and the dielectric layer 36 in a plan view (as viewed from the Z-axis direction), and is superimposed on the dielectric layer 36 in the Z-axis direction. That is, the dielectric layer 37 covers the entire upper surface of the dielectric layer 36. The length (i.e., thickness) of the dielectric layer 37 in the Z-axis direction is, for example, 20 μm or less. The dielectric constant ε ₂₂ of the dielectric layer 37 is higher than the dielectric constant ε ₂₁ , and is, for example, about 2.8 to 3.2. The dielectric layer 37 is, for example, composed of a sheet made of polyester alone.

The dielectric layer 38 is the uppermost layer of the laminate 33. The dielectric layer 38 is provided on the dielectric layer 37. The dielectric layer 38 is a rectangular plate material. The dielectric layer 38 has substantially the same outer shape as the substrate 31, the dielectric layer 36, and the dielectric layer 37 in a plan view (as viewed from the Z-axis direction), and is superimposed on the dielectric layer 37 in the Z-axis direction. That is, the dielectric layer 38 covers the entire upper surface of the dielectric layer 37. The length (i.e., thickness) of the dielectric layer 38 in the Z-axis direction is, for example, 20 μm or less. The dielectric constant ε ₂₃ of the dielectric layer 38 is higher than the dielectric constant ε ₂₂ , and is, for example, about 5.0 to 6.0. The dielectric layer 38 is, for example, composed of a sheet obtained by kneading glass fiber or ceramic powder, which is a high dielectric, into polyester.

The waterproof membrane 34 is a membrane for preventing the intrusion of water. The waterproof membrane 34 covers the substrate 31, the antenna element 32, and the laminate 33. The waterproof membrane 34 is made of a resin that has waterproof and insulating properties. Examples of resins that make up the waterproof membrane 34 include urethane, FRP (fiber reinforced plastic), and Teflon (registered trademark).

The connector 35 is a member for connecting the antenna element 32 to a power source (not shown). The connector 35 is, for example, a coaxial connector such as an SMA connector. In this embodiment, the connector 35 is provided outside the periphery of the substrate 31 and is connected to the end of the wiring pattern that constitutes the antenna element 32.

Next, the operation principle of the antenna device 20 will be described with reference to Fig. 5. Fig. 5 is a diagram for explaining the operation principle of the receiving antenna device shown in Fig. 3. As shown in Fig. 5, an electromagnetic wave reaches the antenna element 22 from the atmospheric layer through the laminate 23. At this time, the electromagnetic wave is incident on the boundary B13 between the atmospheric layer and the dielectric layer 28 at an incident angle θ _in , and is emitted from the boundary B13 at an output angle θ _13. Then, the electromagnetic wave is incident on the boundary B12 between the dielectric layer 28 and the dielectric layer 27 at an incident angle θ ₁₃ , and is emitted from the boundary B12 at an output angle θ _12. Furthermore, the electromagnetic wave is incident on the boundary B11 between the dielectric layer 27 and the dielectric layer 26 at an incident angle θ ₁₂ , and is emitted from the boundary B11 at an output angle θ _11. Then, the electromagnetic wave is incident on the antenna element 22 at an incident angle θ ₁₁ .

Here, using the refractive index n _air of the atmospheric layer, the refractive index n ₁₁ of the dielectric layer 26, the refractive index n ₁₂ of the dielectric layer 27, and the refractive index n ₁₃ of the dielectric layer 28, the following equation (1) holds according to Snell's law.

The dielectric constant ε _air of the atmospheric layer (air) is lower than the dielectric constant ε ₁₃ of the dielectric layer ₂₈ , which is lower than the dielectric constant ε ₁₂ of the dielectric layer 27, which is lower than _{the dielectric constant ε 11 of} the dielectric layer 26. In other words, the relationship of formula (2) holds.

Since the refractive index increases as the dielectric constant increases, the refractive index n _air is lower _than the refractive index n ₁₃ , which is lower than _{the refractive index n 12 ,} which is lower than the refractive index n _11. In other words, the relationship of formula (3) holds.

From equations (1) and (3), the following equation (4) is obtained.

Therefore, as the electromagnetic wave travels through dielectric layer 28, dielectric layer 27, and dielectric layer 26 in this order, the electromagnetic wave is refracted toward antenna element 22, increasing the likelihood that the electromagnetic wave will reach antenna element 22. Note that since waterproof film 24 is thinner than each of the dielectric layers, the effect of waterproof film 24 can be ignored.

Next, the reflection characteristics of the antenna device 20 will be described with reference to Figures 6 and 7. Figure 6 is a diagram showing the reflection characteristics of the receiving antenna device shown in Figure 3. Figure 7 is a diagram showing the reflection characteristics of a receiving antenna device according to a comparative example. The horizontal axis of Figures 6 and 7 indicates frequency (unit: GHz). The vertical axis of Figures 6 and 7 indicates the S11 parameter (unit: dB). A patch antenna element was used as the antenna element 22 of the antenna device 20. The antenna device according to the comparative example differs from the antenna device 20 in that it is not provided on the surface material 11. The reflection characteristics of each antenna device were calculated by a simulation using radio waves of 800 MHz.

As shown in FIG. 7, the antenna device of the comparative example did not obtain a peak at a frequency of 800 MHz. Therefore, it is understood that the antenna device of the comparative example does not function as a receiving antenna. This is thought to be due to strong reflection inside the antenna device. On the other hand, as shown in FIG. 6, the antenna device 20 obtained a peak at a frequency of 800 MHz. Therefore, it is understood that the antenna device 20 functions as a receiving antenna.

Next, the operating principle of the antenna device 30 will be described with reference to Figures 8 to 10. Figure 8 is a diagram for explaining the operating principle of the transmitting antenna device shown in Figure 3. Figure 9 is a diagram for explaining electromagnetic waves radiated from the transmitting antenna device shown in Figure 3. Figure 10 is a diagram for explaining electromagnetic waves radiated from a transmitting antenna device according to a comparative example.

As shown in Fig. 8, an electromagnetic wave is radiated from the antenna element 32 to the atmospheric layer through the laminate 33. At this time, the electromagnetic wave is incident on the boundary B21 between the dielectric layer 36 and the dielectric layer 37 at an incident angle _θ21 , and is emitted from the boundary B21 at an emission angle _θ22 . The electromagnetic wave is then incident on the boundary B22 between the dielectric layer 37 and the dielectric layer 38 at an incident angle _θ22 , and is emitted from the boundary B22 at an emission angle _θ23 . Furthermore, the electromagnetic wave is incident on the boundary B23 between the dielectric layer 38 and the atmospheric layer at an incident angle _θ23 , and is emitted from the boundary B23 at an emission angle _θout .

Here, when the refractive index n ₂₁ of the dielectric layer 36, the refractive index n ₂₂ of the dielectric layer 37, and the refractive index n ₂₃ of the dielectric layer 38 are used, the following formula (5) holds according to Snell's law.

The dielectric constant ε ₂₁ of the dielectric layer 36 is lower than the dielectric constant ε ₂₂ of the dielectric layer 37, which is lower than _{the dielectric constant ε 23 of} the dielectric layer 38. That is, the relationship of formula (6) holds.

Since the refractive index increases as the dielectric constant increases, the refractive index _n21 is lower than the refractive index _n22 , _which is lower than the refractive index _n23 . In other words, the relationship of formula (7) holds.

From equations (5) and (7), the following equation (8) is obtained.

Therefore, as the electromagnetic wave travels through the dielectric layer 36, the dielectric layer 37, and the dielectric layer 38 in this order, it refracts toward the upper surface of the dielectric layer 38. Since the refractive index n _air is lower than the refractive index n ₂₃ , the electromagnetic wave is emitted from the boundary B23 at an output angle θ _r larger than the incident angle θ ₂₃ , but is also emitted at an output angle θ _out equal to the incident angle θ _23. Therefore, the output angle θ _out is smaller than the incident angle θ ₂₁ at the boundary B21 of the electromagnetic wave radiated from the antenna element 32 to the dielectric layer 36. Note that since the waterproof film 34 is thinner than each dielectric layer, the effect of the waterproof film 34 can be ignored.

The antenna device 130 according to the comparative example shown in Fig. 10 differs from the antenna device 30 mainly in that it includes only one dielectric layer 36 instead of the laminate 33. In this case, the electromagnetic wave radiated from the antenna element 32 is incident on the boundary Bc between the dielectric layer 36 and the atmospheric layer at an incident angle _θ21 , and is emitted from the boundary Bc _at an output angle θoutc. Since the refractive index _nair is lower than the refractive index _n21 , the electromagnetic wave is emitted from the boundary Bc at an output angle _θrc larger than the incident angle _θ21 , but is also emitted at an output angle _θoutc equal to the incident angle _θ21 . Therefore, the antenna device 130 functions as an isotropic antenna that radiates electromagnetic waves evenly in all directions.

On the other hand, as described above, the emission angle θ _out of the electromagnetic wave radiated from the antenna device 30 is smaller than the incidence angle θ ₂₁ at the boundary B21 of the electromagnetic wave radiated from the antenna element 32 to the dielectric layer 36. Therefore, as shown in Fig. 9, the antenna device 30 functions as an antenna having directivity whose main axis is the normal direction to the surface 31a.

Next, a method for manufacturing the exterior structure 1 will be described. First, the substrate 21 is prepared. Then, the surface 21a of the substrate 21 is masked so that the area in which the antenna element 22 is to be formed is exposed, and electroless copper plating is performed. Specifically, electroless copper plating is performed using 0.03 mol/L copper sulfate pentahydrate, 0.30 mol/L formalin, and 0.30 mol/L Rochelle salt (complexing agent) under conditions of pH 12.5, bath temperature 20°C to 30°C, and plating speed 1.2 to 1.5 μm/hr.

At this time, a complex such as ruthenium is added as needed as a stabilizer. As a main reaction, copper ions in the bath are precipitated on the surface 21a, and the copper ion concentration and the formalin concentration decrease. During the electroless copper plating process, the copper concentration is maintained constant by sodium thiosulfate titration. As a result, an antenna element 22 is formed on the surface 21a of the substrate 21.

Next, a roll coater is used to form a dielectric layer 26 over the entire surface 21a so as to cover the antenna element 22. Similarly, a roll coater is used to form a dielectric layer 27 over the entire upper surface of the dielectric layer 26, and a dielectric layer 28 over the entire upper surface of the dielectric layer 27. This forms the laminate 23. Then, a roll coater is used to form a waterproof film 24 on the laminate 23. The waterproof film 24 may be formed on the laminate 23 by thermocompression bonding or vapor deposition, for example. In this manner, the antenna device 20 is produced. The antenna device 30 is produced in the same manner as the antenna device 20.

Next, the antenna device 20 and the antenna device 30 are fixed to the desired area of the decorative surface 11a of the surface material 11 by a resin adhesive. The resin adhesive hardens to form the adhesive layer A1 and the adhesive layer A2.

In this manner, the exterior structure 1 is manufactured.

In the exterior structure 1 described above, the antenna element 22 is covered with the dielectric layer 26, the dielectric layer 27 having a dielectric constant _ε12 lower than the dielectric constant _ε11 of the dielectric layer 26 is provided on the dielectric layer 26, and the dielectric layer 28 having a dielectric constant _ε13 lower than the dielectric constant _ε12 of the dielectric layer 27 is provided on the dielectric layer 27. Since the refractive index increases as the dielectric constant increases, the refractive index _n13 of the dielectric layer 28 is lower than the refractive index _n12 of the dielectric layer 27, and the refractive index _n12 of the dielectric layer 27 is lower than the refractive index _n11 of the dielectric layer 26.

Therefore, the emission angle θ ₁₂ when the electromagnetic wave is emitted from the boundary B12 between the dielectric layer 28 and the dielectric layer 27 is smaller than the incident angle θ ₁₃ when the electromagnetic wave is incident on the boundary B12, so the electromagnetic wave is refracted toward the antenna element 22. Furthermore, the emission angle θ ₁₁ when the electromagnetic wave is emitted from the boundary B11 between the dielectric layer 27 and the dielectric layer 26 is smaller than the incident angle θ ₁₂ when the electromagnetic wave is incident on the boundary B11, so the electromagnetic wave is refracted toward the antenna element 22. Furthermore, in the laminate 23, the dielectric constant increases stepwise from the atmospheric layer toward the antenna element 22, so the reflectance of the electromagnetic wave at each of the boundaries B13, B12, and B11 can be reduced. From the above, the possibility that the electromagnetic wave will reach the antenna element 22 is increased, so that the reception efficiency can be improved.

In the exterior structure 1, the antenna element 32 is covered with a dielectric layer 36, a dielectric layer 37 having a dielectric constant _ε22 higher than the dielectric constant _ε21 of the dielectric layer 36 is provided on the dielectric layer 36, and a dielectric layer 38 having a dielectric constant _ε23 higher than the dielectric constant _ε22 of the dielectric layer 37 is provided on the dielectric layer 37. Since the refractive index increases as the dielectric constant increases, the refractive index _n21 of the dielectric layer 36 is lower than the refractive index _n22 of the dielectric layer 37, and the refractive index _n22 of the dielectric layer 37 is lower than the refractive index _n23 of the dielectric layer 38.

Therefore, the emission angle θ ₂₂ when the electromagnetic wave radiated from the antenna element 32 is emitted from the boundary B21 between the dielectric layer 36 and the dielectric layer 37 is smaller than the incident angle θ ₂₁ when the electromagnetic wave is incident on the boundary B21, so the electromagnetic wave is refracted toward the stacking direction of the laminate 33 (the normal direction of the decorative surface 11a). In other words, the electromagnetic wave is refracted toward the boundary B23 between the dielectric layer 38 and the atmospheric layer. Furthermore, the emission angle θ ₂₃ when the electromagnetic wave is emitted from the boundary B22 between the dielectric layer 37 and the dielectric layer 38 is smaller than the incident angle θ ₂₂ when the electromagnetic wave is incident on the boundary B22, so the electromagnetic wave is refracted toward the stacking direction of the laminate 33 (the normal direction of the decorative surface 11a). In other words, the electromagnetic wave is refracted toward the boundary B23 between the dielectric layer 38 and the atmospheric layer. This provides directivity. As a result, it is possible to extend the reach of the electromagnetic wave and increase the intensity of the electromagnetic wave with a simple configuration.

In the laminate 33, the dielectric constant increases stepwise from the antenna element 32 toward the atmospheric layer, so that the reflectance of the electromagnetic waves at each of the boundaries B21 and B22 can be reduced. This makes it possible to improve the transmission efficiency of the electromagnetic waves.

For example, when the antenna device 20 and the antenna device 30 are attached to the surface material 11 using a fixing member such as a bolt, a hole is provided in the surface material 11 for inserting the shaft of the bolt. In this case, there is a risk that rainwater, etc. may enter the room through the hole. To address this problem, in the antenna device 20, an adhesive layer A1 bonds the substrate 21 to the surface material 11. In the antenna device 30, an adhesive layer A2 bonds the substrate 31 to the surface material 11. With these configurations, the antenna device 20 and the antenna device 30 can be fixed to the surface material 11 without drilling a hole in the surface material 11. This reduces the possibility of rainwater, etc. entering the room.

In the antenna device 20, a waterproof film 24 covers the laminate 23. This configuration reduces the possibility that the antenna element 22 will rust, thereby extending the life of the antenna element 22. Similarly, in the antenna device 30, a waterproof film 34 covers the laminate 33. This configuration reduces the possibility that the antenna element 32 will rust, thereby extending the life of the antenna element 32.

The antenna device 20 is mounted on the surface material 11, which is a metal plate, so it can function as a receiving antenna.

If the antenna element 22 is directly pressure-bonded to the surface 21a of the substrate 21, the antenna element 22 will not adhere firmly to the surface 21a and will be prone to peeling off from the surface 21a. To address this issue, the antenna element 22 is formed on the surface 21a by electroless copper plating. This can reduce the possibility of the antenna element 22 peeling off from the surface 21a. Similarly, the antenna element 32 is formed on the surface 31a by electroless copper plating. This can reduce the possibility of the antenna element 32 peeling off from the surface 31a.

Next, a modified example of the exterior structure 1 will be described with reference to Figs. 11 and 12. Fig. 11 is an enlarged perspective view of a portion of the exterior structure according to the modified example. Fig. 12 is a cross-sectional view taken along line XII-XII in Fig. 11.

As shown in Figs. 11 and 12, the antenna device 20 may include a plurality of antenna elements 22 arranged two-dimensionally on a substrate 21. Each antenna element 22 is a patch antenna element having a rectangular plate shape. In this case, the plurality of antenna elements 22 form a phased array antenna. In the example shown in Fig. 11, four patch antenna elements are arranged in the X-axis direction, and six patch antenna elements are arranged in the Y-axis direction. Instead of a connector 25, each antenna element 22 is connected to a power source (not shown) through a via 21c that penetrates the substrate 21 in the Z-axis direction. Note that, for convenience of explanation, the waterproof membrane 24 is omitted from Fig. 11.

Similarly, the antenna device 30 may include a plurality of antenna elements 32 arranged two-dimensionally on the substrate 31. Each antenna element 32 is a rectangular plate-shaped patch antenna element. In this case, the plurality of antenna elements 32 form a phased array antenna. In the example shown in FIG. 11, four patch antenna elements are arranged in the X-axis direction, and six patch antenna elements are arranged in the Y-axis direction. Instead of a connector 35, each antenna element 32 is connected to a power source (not shown) via a via 31c that penetrates the substrate 31 in the Z-axis direction. Note that, for convenience of explanation, the waterproof membrane 34 is omitted from FIG. 11.

Next, an exterior structure according to another embodiment will be described with reference to FIG. 13. FIG. 13 is a cross-sectional view showing an exterior structure according to another embodiment. The exterior structure 1A shown in FIG. 13 differs from the exterior structure 1 mainly in that it includes an exterior material 50 instead of the exterior material 10.

The exterior material 50 is a finishing material used on the exterior of a building. In this embodiment, the exterior material 50 is an exterior wall material. The exterior material 50 is a long member that extends in one direction (X-axis direction), and includes a surface material 51 (metal plate), a back surface material 52, a core material 53, and a gasket 54.

The surface material 51 is a metal plate material. The surface material 51 is formed, for example, by processing a metal plate by roll forming or press forming. Examples of metal plates include iron plates, copper plates, aluminum plates, titanium plates, stainless steel plates, aluminum-zinc alloy plated steel plates, sandwich steel plates (such as vibration-damping steel plates), clad steel plates, enamel steel plates, and laminated steel plates (such as PVC steel plates).

The surface material 51 includes a decorative surface 51a, a connecting portion 51b, a connecting portion 51c, and a fixing portion 51d. The decorative surface 51a is the surface that faces the outside of the building when a building is constructed using the exterior structure 1A.

The connecting portion 51b is a portion for connecting to another exterior material 50 located above the exterior material 50. The connecting portion 51c is a portion for connecting to yet another exterior material 50 located below the exterior material 50. The connecting portion 51b is provided at the upper end of the surface material 51 and extends over the entire length of the surface material 51 in the longitudinal direction. The connecting portion 51c is provided at the lower end of the surface material 51 and extends over the entire length of the surface material 51 in the longitudinal direction. The connecting portion 51b and the connecting portion 51c are configured to be able to fit into each other. Specifically, the connecting portion 51b has a convex shape that protrudes upward. The connecting portion 51c has a concave shape that is recessed upward.

The fixing portion 51d is a portion for fixing the exterior structure 1A. The fixing portion 51d is provided on the upper end of the surface material 51, closer to the back side than the connecting portion 51b, and extends over the entire length of the surface material 51 in the longitudinal direction. The exterior structure 1A is fixed by driving a fixing member such as a nail into the fixing portion 51d.

The back surface material 52 is a sheet-like member. The material constituting the back surface material 52 is the same as the material constituting the back surface material 12, so a detailed description thereof will be omitted. The back surface material 52 may be made of a metal steel plate.

The core material 53 is provided between the front material 51 and the back material 52, and is a member that fills the space defined by the front material 51 and the back material 52 without any gaps. The core material 53 can function as a heat insulating material, a reinforcing material, a bulking material, a soundproofing material, a sound absorbing material, a cushioning material, a fireproofing material, and a condensation prevention material. The constituent material of the core material 53 is the same as the constituent material of the core material 13, so a detailed description thereof will be omitted.

The packing 54 is a member for improving waterproofing and is provided at the connecting portion 51c. The packing 54 is made of, for example, EPM or EPDM.

Next, an exterior structure according to yet another embodiment will be described with reference to FIG. 14. FIG. 14 is a cross-sectional view showing an exterior structure according to yet another embodiment. Exterior structure 1B shown in FIG. 14 differs from exterior structure 1 mainly in that it includes exterior material 60 instead of exterior material 10.

The exterior material 60 is a finishing material used on the exterior of a building. In this embodiment, the exterior material 60 is an exterior wall material. The exterior material 60 is a long member that extends in one direction (X-axis direction), and includes a surface material 61 (metal plate), a back surface material 62, a core material 63, and a gasket 64.

The front surface material 61 and the back surface material 62 are metal plate materials. The front surface material 61 and the back surface material 62 are formed by processing a metal plate, for example, by roll forming or press forming. The constituent materials of the front surface material 61 and the back surface material 62 are the same as the constituent material of the front surface material 51, so a detailed description thereof will be omitted.

The surface material 61 includes a decorative surface 61a, a convex portion 61b, a cover piece 61c, and a concave portion 61d. The decorative surface 61a is the surface that faces the outside of a building when the building is constructed using the exterior structure 1B. The convex portion 61b is a portion for connecting to another exterior material 60 located on top of the exterior material 60. The convex portion 61b is provided at the upper end of the surface material 61 and extends over the entire length of the surface material 61 in the longitudinal direction. The convex portion 61b protrudes upward.

The cover piece 61c is a portion that covers and conceals the joint (joint) between the exterior material 60 and another exterior material 60 located below the exterior material 60. The cover piece 61c is a portion that extends downward from the decorative surface 61a, and is provided over the entire length of the surface material 61 in the longitudinal direction. The recess 61d is a portion for connecting to the other exterior material 60 located below the exterior material 60. The recess 61d is provided at the lower end of the surface material 61, on the back side of the cover piece 61c, and extends over the entire length of the surface material 61 in the longitudinal direction. The recess 61d is recessed upward. The protrusion 61b and the recess 61d have shapes that allow them to fit into each other.

The back surface material 62 includes a protrusion 62a and a recess 62b. The protrusion 62a is a portion for connecting to another exterior material 60 located above the exterior material 60. The protrusion 62a is provided at the upper end of the back surface material 62 and extends over the entire length of the back surface material 62 in the longitudinal direction. The protrusion 62a protrudes upward. The recess 62b is a portion for connecting to yet another exterior material 60 located below the exterior material 60. The recess 62b is provided at the lower end of the back surface material 62 and extends over the entire length of the back surface material 62 in the longitudinal direction. The recess 62b is recessed upward. The protrusion 62a and the recess 62b have shapes that allow them to fit into each other.

The protrusions 61b and 62a are spaced apart from each other in the Z-axis direction, and the protrusions 61b and 62a form a connecting portion that connects to another exterior material 60 located above the exterior material 60. The recesses 61d and 62b are spaced apart from each other in the Z-axis direction, and the recesses 61d and 62b form a connecting portion that connects to yet another exterior material 60 located below the exterior material 60.

The core material 63 is provided between the front material 61 and the back material 62, and is a member that fills the space defined by the front material 61 and the back material 62 without leaving any gaps. The core material 63 can function as a heat insulating material, a reinforcing material, a bulking material, a soundproofing material, a sound absorbing material, a cushioning material, a fireproofing material, and a condensation prevention material. The constituent material of the core material 63 is the same as the constituent material of the core material 13, so a detailed description thereof will be omitted.

The packing 64 is a member for improving waterproofing and is provided in the recess 61d. The packing 64 is made of, for example, EPM or EPDM.

Next, application examples of exterior structures 1, 1A, and 1B will be described with reference to Figures 15 and 16. Figures 15 and 16 are diagrams showing application examples of exterior structures.

In the general house 100 shown in FIG. 15, exterior structure 1 is used for part of the roof material, and exterior structure 1A is used for part of the exterior wall material. In this way, by using exterior structure 1 for the roof of the general house 100, antenna device 20 and antenna device 30 can be provided on the roof of the general house 100. Similarly, by using exterior structure 1A for the exterior wall of the general house 100, antenna device 20 and antenna device 30 can be provided on the exterior wall of the general house 100. Therefore, it is possible to efficiently build a seamless web-like communication network in the space where people live.

The building 200 shown in FIG. 16 is a building made of S (steel), RC (reinforced concrete), or SRC (steel reinforced concrete). Examples of the building 200 include collective housing such as condominiums and apartments, and non-residential buildings such as department stores and office buildings. In the building 200, the exterior structure 1B is used for part of the exterior wall material. Specifically, the exterior structure 1B is used for the exterior wall material of the upper floors and roof of the building 200. When radio waves are transmitted and received using a microcell system, the exterior structure 1B may be used for the exterior material of the lower floors of the building 200.

As described above, by using the exterior structure 1B on the exterior wall of the building 200, the antenna device 20 and the antenna device 30 can be provided on the exterior wall of the building 200. Therefore, it is possible to efficiently build a web-like seamless communication network in the space where people live.

The exterior structure of this disclosure is not limited to the above embodiment.

The exterior structure 1 does not have to include the antenna device 20 and the adhesive layer A1.

The antenna device 20 may include other types of antenna elements, such as half-wave dipole antenna elements and patch antenna elements, as the antenna element 22. The antenna device 30 may include other types of antenna elements, such as half-wave dipole antenna elements and patch antenna elements, as the antenna element 32.

The number of dielectric layers included in the laminate 23 is not limited to three. The laminate 23 may include two dielectric layers, or may include four or more dielectric layers, so long as the dielectric constant increases from the atmospheric layer toward the antenna element 22 in the stacking direction. In other words, of two dielectric layers adjacent to each other in the stacking direction, the dielectric constant of the dielectric layer closer to the antenna element 22 may be higher than the dielectric constant of the other dielectric layer.

The number of dielectric layers included in the laminate 33 is not limited to three. The laminate 33 may include two dielectric layers, or may include four or more dielectric layers, so long as the dielectric constant increases from the antenna element 32 toward the atmospheric layer in the stacking direction. In other words, of two dielectric layers adjacent to each other in the stacking direction, the dielectric constant of the dielectric layer closer to the antenna element 32 may be lower than the dielectric constant of the other dielectric layer.

The antenna device 20 may be fixed to the surface material 11, 51, 61 by other methods instead of the adhesive layer A1. For example, the antenna device 20 may be fixed to the surface material 11, 51, 61 by using a fixing member such as a bolt. Similarly, the antenna device 30 may be fixed to the surface material 11, 51, 61 by other methods instead of the adhesive layer A2. For example, the antenna device 30 may be fixed to the surface material 11, 51, 61 by using a fixing member such as a bolt.

The antenna device 20 may not include a waterproof membrane 24. The antenna device 30 may not include a waterproof membrane 34.

After the exterior materials 10, 50, and 60 are installed, the antenna device 20 and the antenna device 30 may be attached to the exterior materials at desired positions. In this case, the installation positions of the antenna device 20 and the antenna device 30 can be easily adjusted. As a result, it is possible to build a more efficient communication network.

(Additional Note)
[Clause 1]
A metal plate;
A substrate provided on the metal plate;
an antenna element provided on the substrate;
a laminate covering the antenna element;
Equipped with
The laminate includes a first dielectric layer covering the antenna element and a second dielectric layer provided on the first dielectric layer,
The dielectric constant of the second dielectric layer is higher than the dielectric constant of the first dielectric layer.

[Clause 2]
The laminate further includes a third dielectric layer disposed on the second dielectric layer,
2. The exterior structure of claim 1, wherein the dielectric constant of the third dielectric layer is higher than the dielectric constant of the second dielectric layer.

[Clause 3]
3. The exterior construction of claim 1 or 2, further comprising an adhesive layer that adheres the substrate to the metal plate.

[Clause 4]
4. The exterior structure of any one of claims 1 to 3, further comprising a waterproof membrane covering the laminate.

[Clause 5]
5. The exterior structure of any one of claims 1 to 4, further comprising a roofing material including the metal plate as a surface material.

[Clause 6]
5. The exterior structure according to any one of claims 1 to 4, further comprising an exterior wall material including the metal plate as a surface material.

1, 1A, 1B... exterior structure, 10... exterior material (roof material), 11, 51, 61... surface material (metal plate), 20... antenna device, 21... substrate, 22... antenna element, 23... laminate, 24... waterproof membrane, 26... dielectric layer, 27... dielectric layer, 28... dielectric layer, 30... antenna device, 31... substrate, 32... antenna element, 33... laminate, 34... waterproof membrane, 36... dielectric layer (first dielectric layer), 37... dielectric layer (second dielectric layer), 38... dielectric layer (third dielectric layer), 50... exterior material (exterior wall material), 60... exterior material (exterior wall material), A1... adhesive layer, A2... adhesive layer.

Claims (6)

A metal plate;
A substrate provided on the metal plate;
an antenna element provided on the substrate;
a laminate covering the antenna element;
Equipped with
The laminate includes a first dielectric layer covering the antenna element and a second dielectric layer provided on the first dielectric layer,
The dielectric constant of the second dielectric layer is higher than the dielectric constant of the first dielectric layer. The laminate further includes a third dielectric layer disposed on the second dielectric layer,
The exterior structure according to claim 1 , wherein the third dielectric layer has a higher dielectric constant than the second dielectric layer. The exterior structure according to claim 1 or 2, further comprising an adhesive layer that bonds the substrate to the metal plate. The exterior structure according to claim 1 or claim 2, further comprising a waterproof membrane covering the laminate. The exterior structure according to claim 1 or 2, further comprising a roofing material that includes the metal plate as a surface material. The exterior structure according to claim 1 or 2, further comprising an exterior wall material that includes the metal plate as a surface material.

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