Communication apparatus

Abstract

To provide a communication apparatus comprising a film antenna which can easily realize a reduction in thickness.SOLUTION: In a communication system, a communication apparatus 120 comprises: a structure body 121 having a front surface ; and a film antenna 10 attached to the front surface. The film antenna 10 contains a base material 20 containing a first surface and a second surface positioned to the side opposite to the first surface; a first conductive layer positioned on the first surface side; one or more patches 30 having a first outer edge in a plan view; a second conductive layer positioned at a second surface side; and a ground having a second outer edge positioned outside the first outer edge in the plan view. The film antenna 10 is attached to the front surface so that the second conductive layer is opposite to the front surface.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] TECHNICAL FIELD An embodiment of the present disclosure relates to a communication device. [Background technology]

[0002] 2. Description of the Related Art In a communication system, an antenna including a substrate and a conductive layer on the substrate is used. For example, Patent Document 1 proposes using a patch antenna as an antenna device in a mobile communication system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 230039 Brochure Summary of the Invention [Problem to be solved by the invention]

[0004] In order to suppress the antenna from being affected by the surroundings, it is preferable to make the thickness of the base material large, but if the thickness of the base material is large, the installation location and installation form of the antenna are restricted.

[0005] The embodiments of the present disclosure have been made in consideration of these points, and have an object to provide a communication device equipped with a film antenna that can be easily made thin. [Means for solving the problem]

[0006] One embodiment of the present disclosure includes a substrate including a first surface and a second surface opposite the first surface; One or more patches including a first conductive layer located on the first surface side and having a first outer edge in a plan view; The film antenna includes a second conductive layer located on the second surface side, and a ground having a second outer edge located outside the first outer edge in a planar view.

[0007] In the film antenna according to the embodiment of the present disclosure, the first conductive layer may include a metal material.

[0008] In the film antenna according to the embodiment of the present disclosure, the second conductive layer may include a metal material.

[0009] The film antenna according to the embodiment of the present disclosure may include a plurality of the patches located on the first surface side. In this case, the second outer edge may surround the plurality of the patches in a plan view.

[0010] The film antenna according to the embodiment of the present disclosure may include a first patch and a second patch located on the first surface side. In this case, the first patch may have a shape different from a shape of the second patch in a plan view.

[0011] In the film antenna according to the embodiment of the present disclosure, the substrate may contain a fluororesin.

[0012] In the film antenna according to one embodiment of the present disclosure, the substrate may include a plurality of air bubbles.

[0013] In the film antenna according to one embodiment of the present disclosure, the substrate may have a thickness of 2 mm or less.

[0014] In the film antenna according to one embodiment of the present disclosure, the substrate may have a thickness of 10 μm or more.

[0015] In the film antenna according to the embodiment of the present disclosure, the first conductive layer may include a third surface facing the first surface and a fourth surface located on the opposite side of the third surface. In this case, the third surface may have a maximum height roughness of 3 μm or less.

[0016] In the film antenna according to the embodiment of the present disclosure, the first conductive layer may include a third surface facing the first surface and a fourth surface located on the opposite side of the third surface. In this case, the film antenna may include a first cover layer covering the fourth surface.

[0017] In the film antenna according to one embodiment of the present disclosure, the first cover layer may include a colorant.

[0018] In the film antenna according to the embodiment of the present disclosure, the first conductive layer may include a third surface facing the first surface and a fourth surface located on the opposite side of the third surface. In this case, the film antenna may include a first adhesive layer located between the first surface and the third surface.

[0019] One embodiment of the present disclosure is a communication device comprising a structure having a surface, and the above-described film antenna attached to the surface so that the second conductive layer faces the surface.

[0020] In a communication device according to an embodiment of the present disclosure, the surface may include an at least partially curved surface, and the film antenna may be attached to the curved surface.

[0021] In the communication device according to one embodiment of the present disclosure, the structure may be a pillar of an automobile.

[0022] In the communication device according to one embodiment of the present disclosure, the structure may be an inner or outer surface of a building component.

[0023] In the communication device according to an embodiment of the present disclosure, the building component may be a wall, a ceiling, a beam, or a column.

[0024] In the communication device according to one embodiment of the present disclosure, the structure may be an inner or outer surface of a building.

[0025] In the communication device according to an embodiment of the present disclosure, the building component may be a utility pole, a traffic light, an inner wall of a tunnel, or a step in a sidewalk.

[0026] In the communication device according to one embodiment of the present disclosure, the structure may be a part of an automobile, and the communication device may function as a radar for a collision avoidance system.

[0027] In the communication device according to one embodiment of the present disclosure, the first conductive layer may include a plurality of openings.

[0028] In the communication device according to an embodiment of the present disclosure, the second conductive layer may include a plurality of openings.

[0029] In a communication device according to an embodiment of the present disclosure, a frequency of radio waves transmitted or received by the film antenna may be equal to or greater than 3 GHz and equal to or less than 6 GHz, and a dimension of the patch may be equal to or greater than 10 mm and equal to or less than 40 mm.

[0030] In a communication device according to an embodiment of the present disclosure, a frequency of radio waves transmitted or received by the film antenna may be not less than 25 GHz and not more than 30 GHz, and a dimension of the patch may be not less than 2 mm and not more than 20 mm.

[0031] In a communication device according to an embodiment of the present disclosure, a frequency of radio waves transmitted or received by the film antenna may be not less than 50 GHz and not more than 75 GHz, and a dimension of the patch may be not less than 0.5 mm and not more than 10 mm.

[0032] In a communication device according to an embodiment of the present disclosure, a frequency of radio waves transmitted or received by the film antenna may be not less than 75 GHz and not more than 300 GHz, and a dimension of the patch may be not less than 0.2 mm and not more than 5.0 mm.

[0033] In a communication device according to one embodiment of the present disclosure, the structure may have a cylindrical shape, and the film antenna may be attached to the surface of the structure over a distance of more than half the circumference of the surface. Effect of the Invention

[0034] According to an embodiment of the present disclosure, a communication device including a film antenna that can be easily made thin can be provided. [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 illustrates an example of a communication system. [Diagram 2] FIG. 1 illustrates an example of a communication device. [Diagram 3] FIG. 1 is a diagram showing an example of a film antenna. [Figure 4] 4 is a cross-sectional view of the film antenna of FIG. 3 as viewed from the IV-IV direction. [Diagram 5] FIG. 13 is a diagram showing a modified example of the film antenna. [Figure 6] 6 is a diagram showing an example of a communication device equipped with the film antenna of FIG. 5. [Figure 7] 11A and 11B are diagrams for explaining a method for evaluating the flexibility of a film antenna. [Figure 8] FIG. 13 is a diagram showing a modified example of the film antenna. [Figure 9] FIG. 13 is a diagram showing a modified example of a patch. [Figure 10] FIG. 13 shows a modified example of a patch. [Figure 11] FIG. 11 is a cross-sectional view showing a modified example of the film antenna. [Figure 12] FIG. 11 is a cross-sectional view showing a modified example of the film antenna. [Figure 13] FIG. 13 is a diagram showing a modified example of a communication device equipped with a film antenna. [Figure 14] FIG. 13 is a plan view showing a modified example of the film antenna. [Figure 15]FIG. 13 is a rear view showing a modified example of the film antenna. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] The configuration of the film antenna 10 according to an embodiment of the present disclosure will be described in detail with reference to the drawings. Note that the following embodiment is an example of the embodiment of the present disclosure, and the present disclosure is not to be interpreted as being limited to these embodiments. In this specification, terms such as "substrate", "base material", "sheet" and "film" are not distinguished from each other based only on the difference in name. For example, "substrate" and "base material" are concepts that include members that can be called sheets and films. Furthermore, terms such as "parallel" and "orthogonal" and values ​​of lengths and angles that specify shapes and geometric conditions and their degrees, as used in this specification, are interpreted to include a range in which similar functions can be expected without being bound by strict meanings.

[0037] In this specification, when multiple upper limit candidates and multiple lower limit candidates are given for a certain parameter, the numerical range of the parameter may be formed by combining any one of the upper limit candidates and any one of the lower limit candidates. For example, consider a case where "parameter B is, for example, A1 or more, may be A2 or more, or may be A3 or more. Parameter B is, for example, A4 or less, may be A5 or less, or may be A6 or less." In this case, the numerical range of parameter B may be A1 or more and A4 or less, A1 or more and A5 or less, A1 or more and A6 or less, A2 or more and A4 or less, A2 or more and A5 or less, A2 or more and A6 or less, A3 or more and A4 or less, A3 or more and A5 or less, or A3 or more and A6 or less.

[0038] In the drawings referred to in this embodiment, the same parts or parts having similar functions are denoted by the same or similar reference numerals, and repeated explanations thereof may be omitted. In addition, the dimensional ratios of the drawings may differ from the actual ratios for the convenience of explanation, and some components may be omitted from the drawings.

[0039] Hereinafter, embodiments of the present disclosure will be described.

[0040] In recent years, high-frequency radio waves such as microwaves and millimeter waves have begun to be used in various fields. Microwaves are radio waves with a frequency band of approximately 0.3 GHz to 110 GHz. Millimeter waves are radio waves with a frequency band of approximately 30 GHz to 300 GHz. Examples of fields in which they are used include 5th generation mobile communication systems, mobile and automotive communication systems, radar for collision prevention systems, and biosensing in medicine.

[0041] FIG. 1 is a diagram showing an example of a mobile communication system 100. The mobile communication system 100 includes a base station 110, a plurality of communication devices 120, and a plurality of terminal devices 130. The base station 110 is also called a macrocell, and performs wireless communication between the communication device and the terminal device 130 located in an area 115. The communication device 120 is also called a small cell, and performs wireless communication between the communication device and the terminal device 130 located in an area 125. The terminal device 130 is, for example, a smartphone. The area 125 covered by each communication device 120, which is a small cell, may be located inside the area 115 covered by the macrocell, as shown in FIG. 1. Although not shown, the area 125 covered by the small cell may be partially located outside the area 115 covered by the macrocell. In this specification, a small cell means a communication device that covers an area smaller than a macrocell. The small cell may be a so-called femtocell, nanocell, picocell, microcell, or the like.

[0042] 2 is a diagram showing an example of a communication device 120 for configuring an area 125. The communication device 120 includes a structure 121 including a surface 122, and a film antenna 10 attached to the surface 122. The structure 121 is, for example, a utility pole. By attaching the film antenna 10 to the structure 121, the structure 121 can have a communication function. As shown in FIG. 2, the communication device 120 may include a plurality of film antennas 10 attached to the surface 122.

[0043] Although not shown, the film antenna 10 may be mounted on the terminal device 130. That is, the film antenna 10 may take charge of a part of the communication function of the terminal device 130.

[0044] Although not shown, the communication device 120 may include a control device that controls radio waves transmitted by the film antenna 10. The communication device 120 may also include a processing device that processes radio waves received by the film antenna 10. The control device and the processing device may be provided on a common substrate with the film antenna 10. Alternatively, the control device and the processing device may be provided on a member different from the film antenna 10.

[0045] 2, the film antenna 10 includes a substrate 20 and a patch 30 provided on the substrate 20. The patch 30 transmits or receives radio waves. The characteristics of the patch 30 may be affected by a structure 121. For example, when the structure 121 includes a conductive material, the structure 121 may affect the radio waves transmitted or received by the patch 30.

[0046] One method for reducing the influence of the structure 121 is to increase the thickness of the base material 20. However, if the thickness of the base material 20 increases, the installation location and installation form of the film antenna 10 are limited. For example, if the thickness of the base material 20 increases, the flexibility of the film antenna 10 decreases. This makes it difficult to attach the film antenna 10 to the structure 121 having a curved surface. In addition, it makes it difficult to mount the film antenna 10 on a thin device. For example, it makes it difficult to mount the film antenna 10 on a terminal device 130 such as a smartphone.

[0047] Considering these problems, the present embodiment aims to provide a film antenna 10 that can be easily thinned. This can alleviate restrictions on the installation location and installation form of the film antenna 10. For example, as shown in FIG. 2, the film antenna 10 can be attached to a curved surface of a surface 122 of a structure 121. In addition, the film antenna 10 can be mounted inside a thin device such as a smartphone.

[0048] FIG. 3 is a diagram showing an example of a film antenna 10. FIG. 4 is a cross-sectional view of the film antenna 10 of FIG. 3 as viewed from the IV-IV direction. The film antenna 10 includes a substrate 20 including a first surface 21 and a second surface 22, a patch 30 located on the first surface 21 side, and a ground 40 located on the second surface 22 side. The second surface 22 is located on the opposite side to the first surface 21. The substrate 20 is insulating. The patch 30 and the ground 40 are conductive. The substrate 20, the patch 30, and the ground 40 form a capacitor-type antenna.

[0049] The frequency of the radio waves transmitted or received by the film antenna 10 is, for example, 300 MHz or more, and may be 3 GHz or more, 25 GHz or more, or 50 GHz or more. The frequency of the radio waves transmitted or received by the film antenna 10 is, for example, 110 GHz or less, and may be 80 GHz or less. Such radio waves are used in the fifth generation mobile communication system, the inter-vehicle communication system, the radar device for the automobile, and the like.

[0050] 4, the film antenna 10 may include a first adhesive layer 36 located between the substrate 20 and the patch 30. The film antenna 10 may also include a second adhesive layer 46 located between the substrate 20 and the ground 40.

[0051] Each component of the film antenna 10 will be described.

[0052] (base material) The substrate 20 has flexibility, which allows the film antenna 10 to be attached to a structure 121 that includes a curved surface.

[0053] 3, the base material 20 may have a rectangular outer edge in a plan view. For example, the base material 20 may include an outer edge 20Y extending in a first direction D1 and a second direction D2 perpendicular to the first direction D1. The plan view means that the film antenna 10 is viewed along the normal direction of the first surface 21.

[0054] The substrate 20 includes a resin material having a low relative dielectric constant. The relative dielectric constant of the substrate 20 may be 4.0 or less, 3.5 or less, 3.0 or less, 2.5 or less, or 2.0 or less. This can increase the efficiency and gain of the film antenna 10. The relative dielectric constant of the substrate 20 may be 1.0 or more, or 1.5 or more.

[0055] The dielectric tangent tan δ of the substrate 20 may be 0.01 or less, 0.005 or less, 0.001 or less, or 0.0005 or less.

[0056] Examples of the resin material of the substrate 20 include fluororesin, liquid crystal polymer (LCP), polypropylene (PP), modified polypropylene (modified PP), polyimide (PI), and the like. Examples of fluororesin include fully fluorinated resin such as polytetrafluoroethylene (PTFE), partially fluorinated resin such as polychlorotrifluoroethylene (PCTFE), and fluorinated resin copolymer such as ethylene-tetrafluoroethylene copolymer (ETFE). Fluororesin has a relative dielectric constant of, for example, 2.0 or more and 3.0 or less. Liquid crystal polymer has a relative dielectric constant of, for example, 3.0 or more and 3.5 or less. Polypropylene has a relative dielectric constant of, for example, 2.2 or more and 2.6 or less. Polyimide has a relative dielectric constant of about 3.5.

[0057] The substrate 20 may be composed of a single layer or multiple layers.

[0058] The thickness T0 of the substrate 20 is, for example, 2 mm or less, and may be 800 μm or less, 500 μm or less, or 200 μm or less. By reducing the thickness T0, the substrate 20 can have flexibility. The thickness T0 of the substrate 20 is, for example, 10 μm or more, and may be 20 μm or more, 50 μm or more, or 100 μm or more.

[0059] Although not shown, the substrate 20 may contain a plurality of bubbles. That is, the substrate 20 may contain a foamed resin. This allows the relative dielectric constant of the substrate 20 to be reduced.

[0060] (patch) As shown in FIG. 4, the patch 30 includes a first conductive layer 31 located on the first surface 21 side of the substrate 20. The first conductive layer 31 includes a third surface 32 facing the first surface 21 of the substrate 20 and a fourth surface 33 located on the opposite side of the third surface 32. The patch 30 includes a first outer edge 30Y located on the inner side of the outer edge 20Y of the substrate 20 in a plan view. As shown in FIG. 3, the first outer edge 30Y may have a rectangular shape in a plan view. For example, the first outer edge 30Y may extend in a first direction D1 and a second direction D2 perpendicular to the first direction D1.

[0061] 3, a microstrip line 34 may be connected to the patch 30. The patch 30 and the microstrip line 34 may include a common first conductive layer 31.

[0062] The first conductive layer 31 includes a material having electrical conductivity. For example, the first conductive layer 31 includes a metal material such as copper (Cu), gold (Au), silver (Ag), aluminum (Al), or an alloy using these materials. The first conductive layer 31 may include a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The first conductive layer 31 may include a carbon-based conductive material such as graphite, carbon nanotubes, graphene, or fullerene.

[0063] The method for forming the first conductive layer 31 is not particularly limited. For example, the first conductive layer 31 may be formed by a plating method, a printing method, a sputtering method, a vapor deposition method, or the like. The foil constituting the first conductive layer 31 may be attached to the base material 20 via a first adhesive layer 36. The foil may be produced by an electrodeposition method, a rolling method, or the like.

[0064] The thickness T1 of the first conductive layer 31 may be 1 μm or more, or may be 5 μm or more. The thickness of the first conductive layer 31 may be 35 μm or less, or may be 20 μm or less.

[0065] The surface of the first conductive layer 31 is preferably flat. This can reduce transmission loss occurring in the patch 30. For example, the maximum height roughness (Rz) of the third surface 32 of the first conductive layer 31 may be 3.0 μm or less, 2.0 μm or less, or 1.0 μm or less. By making the maximum height roughness of the third surface 32 3.0 μm or less, the transmission loss of the patch 30 at 20 GHz can be reduced to, for example, 6 dB or less.

[0066] The arithmetic mean roughness (Ra) of the third surface 32 of the first conductive layer 31 may be 3.0 μm or less, 2.0 μm or less, or 1.0 μm or less.

[0067] In addition, the smaller the arithmetic mean roughness (Ra) and the maximum height roughness (Rz) of the third surface 32, the lower the adhesion of the third surface 32 to the first surface 21 of the substrate 20. In consideration of this point, it is preferable that a first adhesive layer 36 is provided between the first surface 21 and the third surface 32. This makes it possible to suppress peeling of the patch 30 even when the arithmetic mean roughness (Ra) and the maximum height roughness (Rz) of the third surface 32 are small.

[0068] The arithmetic mean roughness (Ra) and maximum height roughness (Rz) are specified based on JIS B 0601:2013.

[0069] 3, the symbol L1 represents the dimension of the patch 30 in the first direction D1. The symbol W1 represents the dimension of the patch 30 in the second direction D2. The dimensions L1 and W1 are, for example, 40 mm or less, may be 20 mm or less, may be 10 mm or less, or may be 1 mm or less. The dimensions L1 and W1 may be, for example, 0.2 mm or more. The dimensions L1 and W1 may be determined based on the frequency of radio waves that the film antenna 10 transmits or receives. When the frequency of the radio waves is not less than 3 GHz and not more than 6 GHz, the dimensions L1 and W1 may be not less than 10 mm and not more than 40 mm. When the frequency of the radio waves is not less than 25 GHz and not more than 30 GHz, the dimensions L1 and W1 may be not less than 2 mm and not more than 20 mm. When the frequency of the radio waves is not less than 50 GHz and not more than 75 GHz, the dimensions L1 and W1 may be not less than 0.5 mm and not more than 10 mm. When the frequency of the radio waves is not less than 75 GHz and not more than 300 GHz, the dimensions L1 and W1 may be not less than 0.2 mm and not more than 5.0 mm.

[0070] 3, the symbol L0 represents the dimension of the substrate 20 in the first direction D1. The symbol W0 represents the dimension of the substrate 20 in the second direction D2. The dimensions L0 and W0 are larger than the dimensions L1 and W1. For example, the dimensions L0 and W0 may be two or more times the dimensions L1 and W1, or three or more times the dimensions L1 and W1.

[0071] (1st adhesive layer) The first adhesive layer 36 is located between the first surface 21 of the base material 20 and the third surface 32 of the patch 30. The first adhesive layer 36 bonds the first surface 21 and the third surface 32. As shown in Fig. 4, the first adhesive layer 36 may extend outward beyond the first outer edge 30Y of the patch 30. In other words, the first adhesive layer 36 may include a region that does not overlap the patch 30 in a plan view.

[0072] The first adhesive layer 36 may comprise a fluorine-based adhesive containing a fluorine resin. For example, the first adhesive layer 36 may contain a carboxyl group-containing styrene-based elastomer, an epoxy resin, or the like. The relative dielectric constant of the first adhesive layer 36 may be 4.0 or less, 3.5 or less, 3.0 or less, 2.5 or less, or 2.0 or less. The relative dielectric constant of the first adhesive layer 36 may be 1.0 or more, or 1.5 or more.

[0073] The dielectric tangent tan δ of the first adhesive layer 36 may be 0.01 or less, 0.005 or less, 0.001 or less, or 0.0005 or less.

[0074] The thickness of the first adhesive layer 36 is, for example, 30 μm or less, may be 25 μm or less, or may be 20 μm or less. The thickness of the first adhesive layer 36 is, for example, 2 μm or more, may be 5 μm or more, or may be 10 μm or more. The thickness of the first adhesive layer 36 may be even greater, for example, 50 μm or more, or may be 100 μm. An adhesive such as a fluorine-based adhesive may constitute the substrate 20. For example, a first conductive layer 31 and a second conductive layer 41 may be provided on the first surface 21 and the second surface 22 of the substrate 20 obtained by solidifying the adhesive.

[0075] (ground) 4, the ground 40 includes a second conductive layer 41 located on the second surface 22 side of the substrate 20. The second conductive layer 41 includes a fifth surface 42 facing the second surface 22 of the substrate 20, and a sixth surface 43 located on the opposite side to the fifth surface 42. The ground 40 includes a second outer edge 40Y located outside the first outer edge 30Y of the patch 30 in a plan view. The second outer edge 40Y may coincide with the outer edge 20Y of the substrate 20.

[0076] The second conductive layer 41 includes a material having electrical conductivity. As the material of the second conductive layer 41, the materials exemplified for the first conductive layer 31 can be used. The material of the second conductive layer 41 may be the same as the material of the first conductive layer 31, or may be different.

[0077] The thickness T2 of the second conductive layer 41 may be 1 μm or more, or may be 5 μm or more. The thickness of the second conductive layer 41 may be 35 μm or less, 20 μm or less, or 10 μm or less.

[0078] The second conductive layer 41 faces the first conductive layer 31 in the thickness direction of the base material 20. This makes it possible to generate an electric field between the first conductive layer 31 and the second conductive layer 41.

[0079] (Second adhesive layer) The second adhesive layer 46 is located between the second surface 22 of the base material 20 and the fifth surface 42 of the ground 40. The second adhesive layer 46 bonds the second surface 22 and the fifth surface 42 together.

[0080] The material of the second adhesive layer 46 can be the same as the material of the first adhesive layer 36. The material of the second adhesive layer 46 may be the same as the material of the first adhesive layer 36, or may be different.

[0081] The thickness of the second adhesive layer 46 is within the range of thicknesses exemplified for the first adhesive layer 36. The thickness of the second adhesive layer 46 may be the same as or different from the thickness of the first adhesive layer 36.

[0082] (base layer) A member located between the third surface 32 of the first conductive layer 31 and the fifth surface 42 of the second conductive layer 41 is also referred to as an underlayer 50. In the example shown in Fig. 4, the underlayer 50 includes a substrate 20, a first adhesive layer 36, and a second adhesive layer 46. The underlayer 50 is obtained by removing the patch 30 and the ground 40 of the film antenna 10 by etching or the like.

[0083] The relative dielectric constant of the underlayer 50 may be 4.0 or less, 3.5 or less, 3.0 or less, 2.5 or less, or 2.0 or less. This can increase the efficiency and gain of the film antenna 10. The relative dielectric constant of the underlayer 50 may be 1.0 or more, or 1.5 or more.

[0084] The dielectric tangent tan δ of the underlayer 50 may be 0.01 or less, 0.005 or less, 0.001 or less, or 0.0005 or less.

[0085] The thickness T3 of the underlayer 50 is, for example, 2 mm or less, and may be 800 μm or less, 500 μm or less, or 200 μm or less. The thickness T3 of the underlayer 50 is, for example, 10 μm or more, and may be 20 μm or more, 50 μm or more, or 100 μm or more.

[0086] The open resonator method can be used to measure the relative dielectric constant and the dielectric loss tangent. A measurement system that performs the open resonator method includes a network analyzer, a millimeter wave multiplier, a millimeter wave detector, and a Fabry-Perot resonator. As the Fabry-Perot resonator, Keycom Corporation's FPR-40, FPR-50, FPR-60, FPR-75, PFR-90, FPR-110, etc. can be used depending on the frequency.

[0087] A length measuring machine can be used as a measuring device for measuring the thickness, for example, a Nikon Digimicro can be used. If the thickness cannot be measured by a length measuring machine, the thickness may be calculated based on an image of the cross section of a sample of the film antenna 10. A scanning electron microscope can be used as a measuring device for measuring the image.

[0088] The thickness of the entire film antenna 10 is, for example, 2 mm or less, and may be 800 μm or less, 500 μm or less, or 200 μm or less. The thickness of the entire film antenna 10 is, for example, 10 μm or more, and may be 20 μm or more, 50 μm or more, or 100 μm or more.

[0089] Next, the operation of the film antenna 10 having the above-mentioned configuration will be described.

[0090] As described above, the film antenna 10 includes the ground 40 located on the second surface 22 side of the substrate 20. The film antenna 10 is attached to the structure 121 so that the ground 40 faces the structure 121. By including the ground 40 in the film antenna 10, the characteristics of the film antenna 10 can be suppressed from being affected by the structure 121. In addition, the substrate 20 of the film antenna 10 includes a resin material and has a thickness of 2 mm or less. Therefore, the film antenna 10 can have flexibility. These features can alleviate restrictions on the installation location and installation form of the film antenna 10. For example, as shown in FIG. 2, the film antenna 10 can be attached to a curved surface of the surface 122 of the structure 121 such as a utility pole. Since the film antenna 10 can be installed on various structures 121, the area 125 can be easily configured. This can increase the communication capacity of the mobile communication system 100.

[0091] Also, as shown in Fig. 2, by attaching the film antenna 10 to the curved surface of the surface 122 of the structure 121, radio waves can be transmitted in various directions. For example, as shown in Fig. 2, the normal direction of the first film antenna 10 is different from the normal direction of the second film antenna 10 adjacent to the first film antenna 10. Therefore, the direction of the radio waves E1 transmitted from the first film antenna 10 can also be different from the direction of the radio waves E2 transmitted from the second film antenna 10. This makes it possible to easily expand the range of radio wave transmission directions.

[0092] Various modifications can be made to the above-described embodiment. Below, the modified examples will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the first embodiment will be used for parts that can be configured similarly to the above-described embodiment, and duplicated descriptions will be omitted. Also, if it is clear that the effects obtained in the above-described embodiment can also be obtained in the modified examples, the description may be omitted.

[0093] (First Modification) Fig. 5 is a diagram showing a film antenna 10 according to a first modified example. As shown in Fig. 5, the film antenna 10 may include a plurality of patches 30. Each patch 30 can transmit or receive radio waves. By including a plurality of patches 30 in the film antenna 10, the communication capacity of the film antenna 10 can be increased.

[0094] The multiple patches 30 are provided on one substrate 20. For example, similarly to the above-described embodiment, the multiple patches 30 are located on the first surface 21 side of the substrate 20. The second outer edge 40Y of the ground 40 surrounds the multiple patches 30 in a plan view.

[0095] The multiple patches 30 may be arranged in an in-plane direction of the substrate 20. For example, the multiple patches 30 may be arranged in a first direction D1 with a first period P1. The multiple patches 30 may be arranged in a second direction D2 with a second period P2. The first period P1 and the second period P2 may be the same or different. The periods P1 and P2 may be two or more times the dimensions L1 and W1 of the patch 30, or may be three or more times the dimensions L1 and W1 of the patch 30.

[0096] Fig. 6 is a diagram showing an example of a communication device 120 including the film antenna 10 of Fig. 5. As shown in Fig. 6, the film antenna 10 may be wrapped around a surface 122 of a structure 121. For example, when the structure 121 has a cylindrical shape, the film antenna 10 may be attached to the surface 122 over a distance of 1 / 2 or more of the circumference of the surface 122 of the structure 121.

[0097] FIG. 7 is a diagram for explaining a method for evaluating the flexibility of the film antenna 10. In this specification, "flexibility" means a degree of flexibility that does not cause creases in the film antenna 10 when the film antenna 10 is wound into a roll shape with a diameter D in an environment of 25° C. The diameter D is, for example, 300 mm. A "crease" is a deformation that appears in the film antenna 10 in a direction intersecting the direction in which the film antenna 10 is wound. A crease that appears in the film antenna 10 cannot be eliminated even if the film antenna 10 is wound in the opposite direction. Since the film antenna 10 has flexibility, the film antenna 10 can be wrapped around a structure 121 as shown in FIG.

[0098] (Second Modification) FIG. 8 is a diagram showing a film antenna 10 according to a first modified example. As shown in FIG. 8, the film antenna 10 may include a plurality of patches 30 having different shapes. For example, the film antenna 10 may include a first patch 30M and a second patch 30S having a shape different from that of the first patch 30M. The first patch 30M has a dimension L1 in the first direction D1 and a dimension W1 in the second direction D2. The second patch 30S has a dimension L2 in the first direction D1 and a dimension W2 in the second direction D2. The dimension L2 is smaller than the dimension L1. The dimension W2 is smaller than the dimension W1. Therefore, the frequency of the radio wave transmitted or received by the second patch 30S is different from the frequency of the radio wave transmitted or received by the first patch 30. According to this modified example, the band of radio waves that the film antenna 10 can handle can be expanded.

[0099] (Third Modification) In the above-described embodiment, an example has been shown in which the first outer edge 30Y of the patch 30 extends in the first direction D1 and the second direction D2 perpendicular to the first direction D1 in a plan view. That is, an example has been shown in which the shape of the patch 30 in a plan view is rectangular or square. However, the shape of the patch 30 in a plan view is not particularly limited. FIG. 9 is a diagram showing an example of the shape of the patch 30 in a plan view.

[0100] As shown in FIG. 9 by reference numeral 30A, the patch 30 may be circular. As shown by reference numeral 30B, the patch 30 may be elliptical. As shown by reference numeral 30C, the patch 30 may be shaped like a ring. As shown by reference numeral 30D, the patch 30 may be shaped like a portion of a ring in the circumferential direction. As shown by reference numeral 30E, the patch 30 may be triangular. Although not shown, the patch 30 may be other polygonal shapes such as a pentagon, a hexagon, etc. As shown by reference numeral 30F, the patch 30 may be shaped like an arc.

[0101] (Fourth Modification) When the patch 30 has a polygonal shape in a plan view, the corners of the patch 30 may be curved as shown in Fig. 10. This makes it possible to increase the radiation angle of the patch 30. The curvature radius R1 of the corners is, for example, 1 mm or more, and may be 2 mm or more, or may be 3 mm or more.

[0102] (Fifth Modification) Fig. 11 is a cross-sectional view showing a film antenna 10 according to a fifth modified example. As shown in Fig. 11, the film antenna 10 may include a first cover layer 37 that covers the fourth surface 33 of the patch 30. This can improve at least one of the design and weather resistance of the film antenna 10. As shown in Fig. 11, the first cover layer 37 may extend beyond the first outer edge 30Y of the patch 30. That is, the first cover layer 37 may include an area that does not overlap the patch 30 in a plan view.

[0103] Design will be described. When the film antenna 10 is attached to various structures 121, it may be required that the film antenna 10 is not conspicuous. Such a requirement can be achieved by providing the film antenna 10 with a first cover layer 37 having a color, pattern, etc. corresponding to the structure 121. In addition, the surface of the first cover layer 37 may be provided with fine irregularities to give it a color, pattern, or texture, and the adhesion of dirt, bacteria, etc. due to the fine irregularities may be prevented. The first cover layer 37 may contain a coloring material. The composition, distribution, etc. of the coloring material are selected according to the structure 121. The first cover layer 37 may be composed of a single layer or may be composed of multiple layers.

[0104] Weather resistance is a characteristic that prevents deterioration of the film antenna 10 caused by the surrounding environment. For example, when the film antenna 10 is attached to an outdoor structure 121, the film antenna 10 is subject to various environmental influences such as sunlight, rainfall, and snowfall. By providing the film antenna 10 with the first cover layer 37 that is resistant to environmental changes, the weather resistance of the film antenna 10 can be improved.

[0105] The first cover layer 37 includes an insulating material, and may be made of polypropylene, acrylic, or the like.

[0106] The thickness T4 of the first cover layer 37 located on the patch 30 may be 50 μm or more, or may be 100 μm or more. The thickness T4 may be 200 μm or less, or may be 500 μm or less.

[0107] As shown in Fig. 11, the film antenna 10 may include a second cover layer 47 that covers the sixth surface 43 of the ground 40. This can improve at least one of the design and weather resistance of the film antenna 10. For example, when the structure 121 is transparent glass, the second cover layer 47 is visible. The second cover layer 47 has an appropriate color, pattern, etc., so that the design of the film antenna 10 can be improved.

[0108] The material of the second cover layer 47 can be the same as or different from the material of the first cover layer 37. The second cover layer 47 can be made of a single layer or a plurality of layers.

[0109] The thickness T5 of the second cover layer 47 is within the range of the thickness T4 exemplified for the first cover layer 37. The thickness T5 of the second cover layer 47 may be the same as or different from the thickness T4 of the first cover layer 37.

[0110] (Sixth Modification) In the above-described embodiment, an example in which the first adhesive layer 36 exists between the first surface 21 of the substrate 20 and the third surface 32 of the patch 30 has been shown. However, this is not limited thereto, and as shown in FIG. 12, the patch 30 may be fixed to the first surface 21 without using the first adhesive layer 36. For example, the third surface 32 of the patch 30 may be in contact with the first surface 21 of the substrate 20. Such a form may be realized by forming the patch 30 by, for example, a plating method, a printing method, a sputtering method, a vapor deposition method, a cladding method, or the like. Similarly, as shown in FIG. 12, the ground 40 may be fixed to the second surface 22 without using the second adhesive layer 46.

[0111] (Seventh Modification) In the above embodiment, the structure 121 to which the film antenna 10 is attached is an electric pole, but is not particularly limited. For example, the structure 121 may be the inner or outer surface of a wall, ceiling, beam, pillar, or other building component, or may be the inner or outer surface of an electric pole, traffic light, tunnel inner wall, sidewalk step, or other building, or may be the ground, a tree, or other natural structure. The structure 121 may be a part of an automobile. For example, as shown in FIG. 13, the structure 121 may be a pillar of an automobile. In this case, the communication device 120 including the structure 121 and the film antenna 10 may function as a radar of a collision prevention system.

[0112] 13, the structure 121 may include a base portion 123 and a protruding portion 124 protruding from an end portion of the base portion 123 in a normal direction of a surface 122 of the base portion 123. The film antenna 10 may be attached to the surface 122 of the base portion 123. As described above, the film antenna 10 includes the ground 40. Therefore, even if the structure 121 is conductive, it is possible to suppress the characteristics of the film antenna 10 from being affected by the structure 121.

[0113] (Eighth Modification) In the above-described embodiment, an example has been shown in which the first conductive layer 31 constituting the patch 30 extends continuously. However, this is not limited thereto, and as shown in FIG. 14, the first conductive layer 31 may have a plurality of openings 31a formed therein. For example, the first conductive layer 31 may have a so-called mesh shape formed by combining a plurality of linear layers. By forming the openings 31a in the first conductive layer 31, the flexibility of the film antenna 10 can be increased.

[0114] Similar to the first conductive layer 31, a plurality of openings 41a may be formed in the second conductive layer 41 as shown in Fig. 15. By forming the openings 41a in the second conductive layer 41, the flexibility of the film antenna 10 can be increased.

[0115] The above-described multiple modified examples may be combined appropriately and applied to the above-described embodiment. [Explanation of symbols]

[0116] 10 Film Antenna 20 Base material 21 Page 1 22 Side 2 30 Patches 30Y First outer edge 31 First conductive layer 32 Page 3 33 Page 4 34 Microstrip Line 36 1st adhesive layer 37 First Cover Layer 40 Grand 40Y 2nd outer edge 41 Second conductive layer 42 Page 5 43 Page 6 46 Second adhesive layer 47 Second Cover Layer 50 Base layer 100 Mobile communication system 110 base station 115 Communication area covered by base station 110 120 Communication Equipment 121 Structure 122 Surface 125 Communication area covered by communication device 120 130 Terminal Equipment

Claims

1. A communication device, comprising: A structure having a surface; a film antenna attached to the surface; The film antenna includes: a substrate including a first surface and a second surface opposite the first surface; One or more patches including a first conductive layer located on the first surface side and having a first outer edge in a plan view; a ground including a second conductive layer located on the second surface side and having a second outer edge located outside the first outer edge in a plan view; A communication device, wherein the film antenna is attached to the surface so that the second conductive layer faces the surface.

2. The communication device of claim 1 , wherein the structure is an interior or exterior surface of a building component.

3. The communication device according to claim 2 , wherein the building component is a wall, a ceiling, a beam or a column.

4. The communication device of claim 1 , wherein the structure is an interior or exterior surface of a building.

5. The communication device according to claim 4 , wherein the construction is a utility pole, a traffic light, an inner wall of a tunnel, or a step in a sidewalk.

6. the structure is part of a motor vehicle; The communication device of claim 1 , wherein the communication device functions as a radar for a collision avoidance system.

7. The communication device of claim 1 , wherein the first conductive layer includes a plurality of openings.

8. The communication device of claim 1 , wherein the second conductive layer includes a plurality of openings.

9. The frequency of the radio waves transmitted or received by the film antenna is 3 GHz or more and 6 GHz or less, The communication device according to claim 1 , wherein the patch has a dimension of 10 mm or more and 40 mm or less.

10. The frequency of the radio waves transmitted or received by the film antenna is 25 GHz or more and 30 GHz or less, The communication device according to claim 1 , wherein the patch has a dimension of at least 2 mm and at most 20 mm.

11. The frequency of the radio waves transmitted or received by the film antenna is 50 GHz or more and 75 GHz or less, The communication device according to claim 1 , wherein the patch has a dimension of 0.5 mm or more and 10 mm or less.

12. The frequency of the radio waves transmitted or received by the film antenna is 75 GHz or more and 300 GHz or less, The communication device according to claim 1 , wherein the patch has a dimension of 0.2 mm or more and 5.0 mm or less.

13. the structure has a cylindrical shape; The communication device of claim 1 , wherein the film antenna is attached to the surface of the structure over a distance of at least half the circumference of the surface.

Images