Radio wave control structure, radio wave control body, and window material

Abstract

To provide a single radio wave control unit capable of controlling radio waves in a plurality of frequency bands.SOLUTION: A radio wave control structure 10 includes a conductor pattern 3 including a split ring resonator 4 made of a conductor, and a plurality of surrounding portions 5 made of a conductor that surround the split ring resonator 4 and are spaced apart from the split ring resonator 4, wherein a plurality of conductor patterns 3 are arranged.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a radio wave control structure, a radio wave control body, and a window material. [Background technology]

[0002] For example, in areas with good visibility in densely built-up areas, radio waves (e.g., carrier waves) of multiple frequency bands propagate from various directions. When radio waves of multiple frequency bands collide, they interfere with each other, and for example, in the case of a mobile phone, calls may not be able to be made or received, or the conversation may become unstable. For this reason, there is a demand for radio wave control devices to block or transmit radio waves of specific frequencies in order to improve the radio wave environment indoors where communication devices are used.

[0003] Patent Document 1 discloses one aspect of a radio wave control unit (an antenna device in Patent Document 1). In the antenna device of Patent Document 1, a plurality of frequency selective plates are stacked on top of each other, so that radio waves in a plurality of frequency bands can be transmitted and received. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-86952 A Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, it is necessary to stack a plurality of frequency selective plates in the thickness direction, which places restrictions on the installation location.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to provide a radio wave control unit capable of controlling radio waves in a plurality of frequency bands with a single radio wave control unit. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention includes the subject matter described in the following paragraphs.

[0008] Item 1. A split ring resonator made of a conductor; a surrounding portion that surrounds the split ring resonator and is spaced from the split ring resonator, the surrounding portion being made of a conductor; A radio wave control body in which a plurality of the conductor patterns are arranged.

[0009] Item 2. The radio wave control body according to item 1, wherein the minimum width of the conductor portion of each of the surrounding portions is smaller than the minimum width of the conductor portion of each of the split ring resonator portions.

[0010] Item 3. The maximum side L of the enclosed portion max and, The minimum distance L between adjacent surrounding portions min And, When the frequency of radio waves incident on the radio wave control structure is 3.5 GHz, the following formula (1) is satisfied: When the frequency of the radio wave is 3.7 GHz, the following formula (2) is satisfied: 3. The radio wave control structure according to item 1 or 2, which satisfies the following formula (3) when the frequency of the radio wave is 4.5 GHz and 4.7 GHz. Formula (1):L min / L max ≧0.4 Formula (2):L min / L max ≧0.9 Formula (3):L min / L max ≧4.0

[0011] Item 4. The radio wave control body according to any one of items 1 to 3, wherein each of the surrounding portions is continuous in the circumferential direction without being divided.

[0012] Item 5. The radio wave control body according to any one of items 1 to 4, wherein each of the split ring resonating portions is formed in rotational symmetry with respect to the center of gravity of the split ring resonating portion.

[0013] Item 6. The split ring resonator has a split portion separated by a gap, The division unit is a first portion extending along the gap; a second portion extending parallel to the first portion through the gap; 6. The radio wave control device according to any one of items 1 to 5, comprising:

[0014] Item 7. The first portion has the same width in the longitudinal direction of the first portion, Item 7. The radio wave control body according to item 6, wherein the second portion has the same width in the longitudinal direction of the second portion.

[0015] Item 8. The first portion protrudes from a first base portion of the split ring resonator in a direction intersecting the first base portion, 8. The radio wave control body according to item 7, wherein the second portion protrudes from the second base portion of the split ring resonator in a direction intersecting the second base portion.

[0016] Item 9. Having a substrate, A radio wave control body, comprising the radio wave control structure according to claim 1 provided on the substrate.

[0017] Item 10. At least two or more transparent plates are arranged with a gas layer between them, A window material, comprising the radio wave control structure according to any one of claims 1 to 8, provided on a surface of any one of the transparent plates on the side of the gas layer. Effect of the Invention

[0018] The radio wave control unit of the above aspect of the present invention has the advantage that it does not require multiple frequency selective plates and can control radio waves in multiple frequency bands with a single radio wave control unit, thereby reducing restrictions on installation location. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic front view of a radio wave control unit according to an embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view of a radio wave control unit according to the embodiment. [Diagram 3] FIG. 3 is a schematic front view of a radio wave control unit according to the first modification. [Figure 4] FIG. 4 is a schematic diagram of a metal pattern according to the second modification. [Diagram 5] FIG. 5 is a schematic cross-sectional view of a window material according to another modified example. [Figure 6] FIG. 6 is a graph showing the experimental results of Example 1. [Figure 7] FIG. 7 is a graph showing the experimental results of Example 2. [Figure 8] FIG. 8 is a graph showing the experimental results of the comparative example. [Figure 9] FIG. 9 is a graph showing the experimental results of Example 3. [Figure 10] FIG. 10 is a graph showing the experimental results of Example 3. [Figure 11] FIG. 11 is a graph showing the experimental results of Example 3. [Figure 12] FIG. 12 is a graph showing the experimental results of Example 3. [Figure 13] FIG. 13 is a graph showing the experimental results of Example 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] <Embodiment> Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The radio wave control body 1 of this embodiment is a sheet-shaped radio wave reflector capable of reflecting radio waves. The radio wave control body 1 according to this embodiment can reflect radio waves of two or more specific frequency bands. Alternatively, the radio wave control body 1 can transmit only radio waves of two or more specific frequency bands and reflect other radio waves.

[0021] The radio wave control body 1 according to this embodiment is a structure using a metamaterial, as shown in FIG. 1. As shown in FIG. 2, the radio wave control body 1 has a base material 21, and a radio wave control structure 10 is provided on the base material 21. The radio wave control structure 10 has a plurality of metal patterns (conductor patterns) 3 arranged periodically, and the plurality of metal patterns 3 are covered with a protective film 23. As shown in FIG. 1, each metal pattern 3 includes a split ring resonator 4 and an enclosing portion 5 surrounding the split ring resonator 4. The split ring resonator 4 and the enclosing portion 5 are made of a conductor. The enclosing portion 5 is separated from the split ring resonator 4 and is not in contact with the split ring resonator 4. Note that the plurality of metal patterns 3 do not necessarily have to be arranged periodically.

[0022] By being configured in this manner, the radio wave control body 1 according to this embodiment can have resonance points for radio waves in a plurality of frequency bands. As a result, since it is possible to have resonance points for radio waves in a plurality of frequency bands without stacking a plurality of radio wave control bodies 1, there is an advantage that one radio wave control body 1 can reflect or transmit radio waves in a plurality of frequency bands, and there are few restrictions on the installation location. In this embodiment, as an example of the radio wave control body 1, a radio wave control body 1 that reflects radio waves will be described.

[0023] In this specification, the term "sheet" refers to a shape in which the thickness of the object is 10% or less of the maximum length between the outer edges in a plan view. When the shape in a plan view is rectangular, the "maximum length between the outer edges in a plan view" refers to the length of the diagonal. When the shape in a plan view is circular, the "maximum length between the outer edges in a plan view" refers to the length of the diameter. In this specification, membranes, foils, films, etc. are also included in the term "sheet."

[0024] For example, radio waves transmitted from a transmitter are incident on the radio wave control unit 1. The transmitter is a communication device having a transmission antenna capable of outputting a wireless signal using radio waves as a medium. Examples of the transmitter include a fixed base station, a mobile base station, a radio wave transmitter, a wireless terminal, and a local 5G base station.

[0025] The radio waves reflected by the radio wave control unit 1 are transmitted to, for example, a receiver. The receiver is a communication device having a receiving antenna. Examples of receivers include smartphones, mobile phones, tablet terminals, notebook PCs, portable game consoles, repeaters, radios, and televisions.

[0026] The radio wave that can be reflected by the radio wave control body 1 according to this embodiment is, for example, a radio wave in a specific frequency band in which the frequency of the incident wave belongs to any of the ranges of 3 GHz to 5 GHz, 25 GHz to 30 GHz, and 100 GHz to 300 GHz. Among these, it is preferable to set the specific frequency band so that the reflection efficiency is high in the 5G frequency band (3 GHz to 5 GHz, 25 GHz to 30 GHz).

[0027] Each element of the radio wave control body 1 according to this embodiment will be described in more detail below. In this specification, "parallel" refers not only to the case where two straight lines, surfaces, etc. (hereinafter, "straight lines, etc.") do not intersect even when extended, but also includes the case where the angle between the two straight lines, etc. is within a range of 10°. Furthermore, "orthogonal" refers to the case where two straight lines, etc. intersect within a range of 90°±10°. However, even if two straight lines, etc. do not intersect directly, if they intersect when extended, they are included in "orthogonal."

[0028] (Overall composition) The radio wave control unit 1 is formed in a quadrangle as shown in Fig. 1. However, the radio wave control unit 1 is not limited to a quadrangle, and may have a geometric shape such as a triangle, a pentagon, a hexagon, a circle, an ellipse, or a non-geometric shape.

[0029] It is preferable that the radio wave control body 1 has flexibility. This allows the radio wave control body 1 to be deformed and installed according to the shape of the installation surface. The thickness of the radio wave control body 1 is preferably 0.01 mm or more, more preferably 0.05 mm or more, and even more preferably 0.2 mm or more. On the other hand, the upper limit of the thickness of the radio wave control body 1 is preferably 0.5 mm or less, and more preferably 0.4 mm or less. When the thickness of the radio wave control body 1 is 0.01 mm or more, it is possible to maintain strength while having flexibility. When the thickness of the radio wave control body 1 is 0.5 mm or less, it is easy to deform the radio wave control body 1.

[0030] The radio wave control body 1 preferably has visible light transmissibility. That is, the radio wave control body 1 is preferably transparent. This allows the radio wave control body 1 to be installed without being conspicuous even if the installation surface is a window glass or a transparent smoke-proof wall. In this specification, "transparent" means that the light transmittance is 10% or more with respect to the peak wavelength of the light before incidence, preferably 50% or more, and more preferably 80% or more. In other words, "semi-transparent" with a light transmittance of, for example, about 30% with respect to the peak wavelength of the light before incidence is also included in "transparent" in this specification. In addition, the transparent plate 2 is not limited to being colorless and transparent, and may be colored.

[0031] The modulus of longitudinal elasticity of the radio wave control body 1 is preferably 0.01 GPa or more and 80 GPa or less. By setting the modulus of longitudinal elasticity within the above range, the radio wave control body 1 becomes easily deformable, and the radio wave control body 1 can be curved and attached to a curved surface with a radius of curvature of 200 mm or more without breaking. The modulus of longitudinal elasticity is measured in accordance with JIS K7127-1999.

[0032] (Base material 21) The substrate 21 supports the metal pattern 3. In this embodiment, the external shape of the substrate 21 is a quadrangle (more specifically, a square) in a plan view. The thickness of the substrate 21 is uniform over the entire surface. However, the thickness of the substrate 21 does not have to be uniform, and the substrate 21 may be formed into a three-dimensional shape. Examples of the three-dimensional shape include a wedge shape, a shape having a partially spherical surface, and a shape having projections and recesses.

[0033] In this embodiment, the base material 21 is preferably transparent. On the surface of the base material 21 opposite to the metal pattern 3, an adhesive layer (hereinafter, referred to as a first adhesive layer 22) is provided.

[0034] Examples of the substrate 21 include synthetic resin, FRP (Fiber Reinforced Plastics), carbon, and glass. Examples of the synthetic resin include one or more selected from the group consisting of PET (polyethylene terephthalate), polyethylene, polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polyester, polyformaldehyde, polyamide, polyphenylene ether, vinylidene chloride, polyvinyl acetate, polyvinyl acetal, AS resin, ABS resin, acrylic resin, fluororesin, nylon resin, polyacetal resin, polycarbonate resin, polyamide resin, and polyurethane resin. The substrate 21 may be a composite material of these synthetic resins. The substrate 21 according to this embodiment is composed of a PET sheet.

[0035] The thickness of the substrate 21 is, for example, preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. On the other hand, the upper limit of the thickness of the substrate 21 is, for example, preferably 500 μm or less, more preferably 130 μm or less, and even more preferably 100 μm or less.

[0036] The substrate 21 is preferably flexible. The modulus of longitudinal elasticity of the substrate 21 is, for example, preferably 0.01 GPa or more, more preferably 1 GPa or more, and even more preferably 8 GPa or more. On the other hand, the upper limit of the modulus of longitudinal elasticity of the substrate 21 is, for example, preferably 80 GPa or less, more preferably 30 GPa or less, and even more preferably 20 GPa or less.

[0037] (Metal pattern 3) The multiple metal patterns 3 are made of a conductor. The multiple metal patterns 3 are formed on a substrate 21. All of the multiple metal patterns 3 are formed in the same shape and have a periodic structure. In other words, one metal pattern 3 represents the smallest unit of the metasurface.

[0038] Examples of methods for forming the metal pattern 3 on the substrate 21 include a method for laminating a thin film in which the metal pattern 3 is embedded in a thin-film dielectric on the substrate 21, and a method for forming the metal pattern 3 on the substrate 21 without using a dielectric. An example of a method for forming the metal pattern 3 on the substrate 21 is as follows.

[0039] Photoresist is applied onto the substrate 21, covered with a photomask on which the metal pattern 3 is formed, exposed to ultraviolet light, and the exposed portion is removed with a developer. Next, metal is vapor-deposited onto the portion from which the photoresist has been removed, and then the photoresist is removed, forming the metal pattern 3 on the substrate 21. Note that, although an example using positive-type photolithography has been described here, negative-type photolithography may also be used.

[0040] The dielectric used here preferably has a relative dielectric constant of 1.5 or more, more preferably 2.5 or more, and even more preferably 3 or more. Examples of the dielectric include acrylic resin, PET (polyethylene terephthalate), and a mixture of acrylic and air.

[0041] Examples of the conductor include at least one of silver, gold, copper, platinum, aluminum, titanium, silicone, indium tin oxide, and alloys (e.g., alloys containing nickel, chromium, and molybdenum). Examples of alloys containing nickel, chromium, and molybdenum include various grades of Hastelloy B-2, B-3, C-4, C-2000, C-22, C-276, G-30, N, W, and X.

[0042] The thickness of the metal pattern 3 is preferably 10 nm or more, more preferably 30 nm or more, and even more preferably 100 nm or more. On the other hand, the upper limit of the thickness of the metal pattern 3 is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 4 μm or less. When the thickness of the metal pattern 3 is 10 nm or more, appropriate radio wave intensity can be ensured.

[0043] Each metal pattern 3 has a side of preferably 15 mm or more, more preferably 20 mm or more, and even more preferably 25 mm or more. On the other hand, each metal pattern 3 has a side of preferably 50 mm or less, more preferably 40 mm or less, and even more preferably 30 mm or less.

[0044] The distance between adjacent metal patterns 3 is preferably equal to or less than the wavelength of the radio waves to be reflected. Specifically, it is preferably equal to or less than 20 mm, and more preferably equal to or less than 15 mm. On the other hand, the distance between adjacent metal patterns 3 may be 0 mm or more, and is preferably equal to or more than 5 mm, and more preferably equal to or more than 10 mm.

[0045] The metal pattern 3 preferably has a relative dielectric constant of at least 7. On the other hand, the upper limit of the relative dielectric constant is preferably 10,000 or less.

[0046] As shown in Fig. 1, each metal pattern 3 includes a split ring resonator 4 and an enclosing portion 5 surrounding the split ring resonator 4 in a one-to-one relationship. The shape of the metal pattern 3 may be various depending on the desired frequency band of radio waves for which radio wave reflectivity is to be increased, but here, the pattern shown in Fig. 1 is taken as an example and described. The metal pattern 3 of this embodiment can increase radio wave reflectivity in three frequency bands: a frequency band near 2 GHz, a frequency band near 3.4 GHz, and a frequency band near 5.1 GHz. Note that one enclosing portion 5 may surround multiple split ring resonators 4.

[0047] (Split ring resonator 4) The split-ring resonator 4 is a metal microstructure having a structure finer than the wavelength of the target radio wave (electromagnetic wave). The split-ring resonator 4 corresponds to a split-ring resonator in a metasurface (metamaterial), and is also called a split-ring resonator (SRR). Therefore, the shape of the split-ring resonator 4 excludes simple shapes that do not include the following linear bodies.

[0048] The split ring resonator 4 according to the present embodiment is composed of a plurality of linear bodies. Each linear body extends thinly. In the present embodiment, each linear body is linear. It is preferable that each split ring resonator 4 is formed rotationally symmetrically about the center of gravity G1 of each split ring resonator 4. The split ring resonator 4 according to the present embodiment is a figure in which a figure (approximately T-shaped figure) consisting of a first linear body 41 extending horizontally from the center of gravity G1 and a second linear body 42 extending vertically from the middle part of the first linear body 41 is rotated 90° around the center of gravity G1. That is, the split ring resonator 4 according to the present embodiment is a figure with four-fold symmetry.

[0049] The multiple linear bodies are all formed with the same width in the longitudinal direction. The line width is, for example, preferably 10 μm or more, more preferably 1 mm or more, and even more preferably 1.8 mm or more. On the other hand, the line width is preferably 2 mm or less. By making the line width of the linear bodies 2 mm or less, the degree of freedom in designing the metal pattern 3 can be improved. By making the line width of the linear bodies 10 μm or more, the productivity of the metal pattern can be maintained while suppressing costs.

[0050] (Box 5) The surrounding portion 5 is provided on the base material 21 and surrounds the split ring resonator 4. The surrounding portion 5 is spaced apart from the split ring resonator 4. The minimum distance L2 from the split ring resonator 4 to the surrounding portion 5 is preferably 50% or more, more preferably 80% or more, and even more preferably 100% or more, of the width (line width) of the linear body of the split ring resonator 4. The maximum distance L3 from the split ring resonator 4 to the surrounding portion 5 is preferably less than the wavelength of radio waves in the frequency band in which radio wave reflectivity is to be increased.

[0051] The surrounding portion 5 is formed in a rectangular shape. In this case, the maximum side L of the surrounding portion 5 is max and the minimum distance L between adjacent surrounding portions 5 min It is preferable that when the frequency of the radio waves incident on the radio wave control structure is 3.5 GHz, the following formula (1) is satisfied, when the frequency of the radio waves is 3.7 GHz, the following formula (2) is satisfied, and when the frequency of the radio waves is 4.5 GHz and 4.7 GHz, the following formula (3) is satisfied. Formula (1):L min / L max ≧0.4 Formula (2):L min / L max ≧0.9 Formula (3):L min / L max ≧4.0 This allows the radio wave control unit 1 to efficiently transmit radio waves of a specific frequency.

[0052] However, the surrounding portion 5 may be, for example, a triangular shape, a pentagonal shape, a hexagonal shape, a circular shape, an elliptical shape, etc. It is preferable that the surrounding portion 5 is continuous in the circumferential direction.

[0053] In this specification, "continuous" includes not only an embodiment in which the wire is continuous without being divided in the circumferential direction, but also an embodiment in which the wire is mostly continuous (with a part being slightly separated). A "slightly separated" part is within the continuous category if it is 5% or less of the circumferential length.

[0054] The line width of the surrounding portion 5 is preferably the same over the entire length. In this embodiment, the line width of the surrounding portion 5 is the same as the width of the linear body of the split-ring resonator 4, but may be smaller than the width of the linear body of the split-ring resonator 4.

[0055] (Protective film 23) The protective film 23 can protect the metal patterns 3 by covering the multiple metal patterns 3. The protective film 23 has a size corresponding to the base material 21 in a plan view. The protective film 23 can be, for example, a film made of a synthetic resin. Examples of the synthetic resin include one or more types selected from the group consisting of PET (polyethylene terephthalate), COP (cycloolefin polymer), polyethylene, polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polyester, polyformaldehyde, polyamide, polyphenylene ether, vinylidene chloride, polyvinyl acetate, polyvinyl acetal, AS resin, ABS resin, acrylic resin, fluororesin, nylon resin, polyacetal resin, polycarbonate resin, polyamide resin, and polyurethane resin.

[0056] It is preferable that protective film 23 contains fluorine. Protective film 23 containing fluorine can prevent transmission of ultraviolet rays, and therefore can protect multiple metal patterns 3 from ultraviolet rays.

[0057] The thickness of the protective film 23 is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more. On the other hand, the upper limit of the thickness of the protective film 23 is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 25 μm or less.

[0058] The protective film 23 is adhered to the substrate 21 via an adhesive layer (hereinafter, referred to as the second adhesive layer 24). Examples of the second adhesive layer 24 include a synthetic resin, a rubber adhesive sheet, etc. Examples of the synthetic resin include an acrylic resin, a silicone resin, and a polyvinyl alcohol resin.

[0059] (First adhesive layer 22, second adhesive layer 24) The first adhesive layer 22 is provided on the surface of the base material 21 opposite to the metal pattern 3. This allows the radio wave control body 1 to be attached to an installation surface. The second adhesive layer 24 is disposed between the protective film 23 and the base material 21. Examples of materials for the first adhesive layer 22 and the second adhesive layer 24 include synthetic resins, rubber adhesive sheets, and the like. Examples of synthetic resins include synthetic resins such as acrylic resins, silicone resins, and polyvinyl alcohol resins.

[0060] <Modification> The above embodiment is merely one of various embodiments of the present invention. The embodiment can be modified in various ways depending on the design, etc., as long as the object of the present invention can be achieved. Modifications of the embodiment are listed below. The modifications described below can be applied in appropriate combination.

[0061] (Variation 1) The metal pattern 3 may be, for example, as shown in Fig. 3. As shown in Fig. 3, the metal pattern 3 includes a split ring resonator 4 and an enclosing portion 5.

[0062] The split-ring resonator 4 includes a rectangular frame portion 49 formed of four linear bodies, a split portion 40, and a plurality of base portions 45, 46 connecting the split portion 40 to the frame portion 49.

[0063] The multiple bases 45, 46 protrude from opposing linear bodies of the frame-shaped portion 49 toward the inside of the frame-shaped portion 49. One of the multiple bases is referred to as the "first base 45" and the other is referred to as the "second base 46." The first base 45 extends in a direction intersecting (here, perpendicular to) the corresponding linear body. The second base 46 extends in a direction intersecting (here, perpendicular to) the corresponding linear body.

[0064] The split section 40 is a split portion of the split-ring resonator 4. The split section 40 includes a first portion 43 extending from a first base portion 45 and a second portion 44 extending from a second base portion 46. The first portion 43 extends in a direction intersecting (here, perpendicular to) the first base portion 45. The second portion 44 extends in a direction intersecting (here, perpendicular to) the first base portion 45. In this embodiment, the first portion 43 and the second portion 44 are parallel to each other and are separated from each other by a gap G2. In other words, the first portion 43 and the second portion 44 extend along the gap G2.

[0065] The first portion 43 preferably has the same width over its entire length in the longitudinal direction, and the second portion 44 preferably has the same width over its entire length in the longitudinal direction.

[0066] The surrounding portion 5 surrounds the split ring resonator 4. The surrounding portion 5 has a shape in which the outer shape of the split ring resonator 4 is offset. The minimum width (i.e., line width) of the conductor portion of the surrounding portion 5 is preferably smaller than the minimum width (i.e., line width of the linear body constituting the frame portion 49) of the conductor portion of the ring resonator 4. This makes it possible to narrow each range of a specific frequency band that can be reflected, blocked, or transmitted, and to improve the responsiveness of the surrounding portion 5.

[0067] (Variation 2) The metal pattern 3 may be, for example, as shown in Fig. 4. As shown in Fig. 4, the metal pattern 3 includes a split ring resonator 4 and a circular surrounding portion 5.

[0068] The split-ring resonator 4 includes four linear bodies (hereinafter, referred to as fourth linear bodies) separated by a gap G2, and a connector 48 that electrically connects the four fourth linear bodies to each other. Each of the four linear bodies is formed in a quarter arc shape, and is arranged to form a circle as a whole. The connector 48 is formed in a substantially X-shape.

[0069] Similar to the split ring resonator 4 of the embodiment, the split ring resonator 4 is formed to be rotationally symmetric about the center of gravity G1 of the split ring resonator 4. The split ring resonator 4 of this modification has a four-fold symmetric shape.

[0070] The surrounding portion 5 surrounds the split ring resonator 4. The surrounding portion 5 has a shape obtained by offsetting the outer shapes of the four fourth linear bodies, and is formed in a circular shape. As in the first modification, it is preferable that the minimum width (i.e., the line width) of the conductor portion of the surrounding portion 5 is smaller than the minimum width (i.e., the line width) of the conductor portion of the ring resonator (i.e., the line width of the fourth linear bodies).

[0071] (Other variations) In the above embodiment and modified examples, the surrounding portion 5 is composed of one linear body, but it may be composed of multiple linear bodies (e.g., double circles, triple circles, etc.) spaced apart in the inward and outward direction, for example.

[0072] In the above embodiment and modified examples, the split ring resonator 4 is composed of multiple linear bodies, but in the part corresponding to the split ring resonator 4, the conductor and the gap may be reversed, for example, by making the linear bodies a gap and the other parts a conductor.

[0073] In the above embodiment, the radio wave control body 1 is configured to set the specific frequency band to two or more bands and increase the reflection efficiency, but it may be configured to block radio waves in a specific frequency band without reflecting them. Also, the radio wave reflector may be configured to transmit only radio waves in a specific frequency band and reflect radio waves in other bands.

[0074] In the above embodiment, the radio wave control structure 10 is provided on the base material 21, but the base material 21 is not essential, and for example, the radio wave control structure 10 may be provided on a Low-E film of a window material.

[0075] The radio wave control structure 10 according to this embodiment can be applied to window materials. One application example is shown in Fig. 5. The window material 11 shown in Fig. 5 includes two transparent plates 12, 13 and a spacer 14, and the transparent plates 12, 13 are arranged with a gas layer 15 in between. The radio wave control structure 10 is provided on the surface of the transparent plate 12 on the gas layer 15 side. The radio wave control structure 10 may also be provided on the surface of the transparent plate 13 on the gas layer 15 side.

[0076] <Example> A test was conducted to confirm the effects of the radio wave control unit according to the present invention. Test pieces of the radio wave control unit according to the embodiment and the comparative example were prepared, and evaluation tests were conducted by the following method. However, the radio wave control unit according to the present invention is not limited to the embodiment.

[0077] Example 1 The radio wave control body of Example 1 is the same as the radio wave control body of the embodiment. As the radio wave control body of Example 1, a metal pattern with a thickness of 1.8 μm was formed on a PET film (substrate) with a thickness of 0.1 mm. Copper was used for the pattern. The linear body constituting the surrounding part and the linear body constituting the split ring resonator part had the same line width of 1.9 mm.

[0078] Example 2 The radio wave control body of Example 2 was surrounded by a rectangular surrounding portion (line width 1.9 mm) with a gap of 2.7 mm from the surrounding portion of Example 1. In other words, the surrounding portion was a surrounding portion that doubly surrounded the split-ring resonating portion.

[0079] (Comparative Example) The test piece of the comparative example was different from that of the example in that the metal pattern did not have a surrounded portion, but otherwise had the same structure.

[0080] (Test Method) In an anechoic chamber, a network analyzer (Keysight: PNA E8363C) was connected to a transmitter and a receiver (FT-RF: HA-0218G-NF) with RF cables. The transmitter and receiver were set up so that the distance between the antennas was 60 cm, and a test piece was placed at the center of the transmitter and receiver to perform measurements.

[0081] The frequency was changed from 1 GHz to 6 GHz, and the strength of the radio waves received by the receiver was measured at each frequency.

[0082] The test results are shown in Figures 6, 7, and 8. Figure 6 shows the results of Example 1, Figure 7 shows the results of Example 2, and Figure 8 shows the results of the Comparative Example. In the graphs, the vertical axis represents radio wave intensity, and the horizontal axis represents frequency.

[0083] 6 and 8, the comparative example has one resonance point at 2.6 GHz, whereas Example 1 has three resonance points at 2 GHz, 3.4 GHz, and 5.1 GHz. This shows that by forming the split-ring resonator in the metal pattern so that it is surrounded by an enclosing part, the radio waves in the frequency bands that can be reflected, blocked, or transmitted can be set to two or more specific frequency bands.

[0084] 6 and 7, Example 1 has three resonance points at 2 GHz, 3.4 GHz, and 5.1 GHz, whereas Example 2 has four resonance points at 2 GHz, 3.6 GHz, 4.3 GHz, and 5.2 GHz. This shows that by changing the enclosed portion in the metal pattern, it is possible to adjust the amount of radio waves in a specific frequency band that can be reflected, blocked, or transmitted.

[0085] Example 3 The radio wave control unit of Example 3 is the radio wave control unit of the embodiment, in which the metal pattern is replaced with the metal pattern 3 shown in Fig. 9. The split ring resonator 4 was a cross shape with a width of 1 mm. The maximum side L of the surrounding portion 5 was max and the minimum distance L between adjacent surrounding portions 5 minWhile changing the above, we performed a simulation to calculate the amount of transmission (dB) when radio waves of a specific frequency were incident on the radio wave control device.

[0086] Figure 10 (A) and (B) show the L min / L max 10 is a graph showing the relationship between the maximum side L of the enclosing portion 5 and the amount of radio wave transmission. max and the minimum distance L between adjacent surrounding portions 5 min However, it was found that by satisfying the following formula (1), the radio wave transmission amount becomes 0 dB or more. Formula (1):L min / L max ≧0.4

[0087] Figure 11 (A) and (B) show the L min / L max 10 is a graph showing the relationship between the maximum side L of the enclosing portion 5 and the amount of radio wave transmission. max and the minimum distance L between adjacent surrounding portions 5 min However, it was found that by satisfying the following formula (2), the radio wave transmission amount becomes 0 dB or more. Formula (2):L min / L max ≧0.9

[0088] 12 and 13 show the L min / L max From these results, when the frequency of the radio wave incident on the radio wave control structure is 4.5 GHz and 4.7 GHz, the maximum side L max and the minimum distance L between adjacent surrounding portions 5 min However, it was found that by satisfying the following formula (3), the radio wave transmission amount becomes 0 dB or more. Formula (3):L min / Lmax ≧4.0 [Explanation of symbols]

[0089] 1 Radio Control Body 21 Base material 3 Metal Pattern 4-part ring resonator 40 Division 43 Part 1 44 Part 2 45 1st base 46 Second base 5 Enclosed section 10 Radio wave control structure 11 Window materials 12 Transparent plate 13 Transparent plate 14 Gas Layer G1 center of gravity G2 Gap

Claims

1. A split ring resonator made of a conductor; a surrounding portion that surrounds the split ring resonator and is spaced from the split ring resonator, the surrounding portion being made of a conductor; A plurality of the conductor patterns are arranged. Radio wave control structure.

2. a minimum width of a conductor portion of each of the surrounding portions is smaller than a minimum width of a conductor portion of each of the split-ring resonator portions; The radio wave control structure according to claim 1 .

3. The maximum side L of the enclosed portion ｍａｘ and, The minimum distance L between adjacent surrounding portions ｍｉｎ And, When the frequency of radio waves incident on the radio wave control structure is 3.5 GHz, the following formula (1) is satisfied: When the frequency of the radio wave is 3.7 GHz, the following formula (2) is satisfied: The radio wave control structure according to claim 1 , which satisfies the following formula (3) when the frequency of the radio wave is 4.5 GHz and 4.7 GHz. Formula (1): L ｍｉｎ / L ｍａｘ ≧0.4 Formula (2): L ｍｉｎ / L ｍａｘ ≧0.9 Formula (3): L ｍｉｎ / L ｍａｘ ≧4.0

4. Each of the surrounding portions is continuous without being divided in the circumferential direction. The radio wave control structure according to claim 1 .

5. Each of the split ring resonating portions is formed rotationally symmetrically about the center of gravity of the split ring resonating portion. The radio wave control structure according to claim 1 .

6. the split ring resonator has split portions separated by a gap, The division unit is a first portion extending along the gap; a second portion extending parallel to the first portion through the gap; having The radio wave control structure according to claim 1 .

7. The first portion has the same width in a longitudinal direction of the first portion, The second portion has the same width in a longitudinal direction of the second portion. The radio wave control structure according to claim 6.

8. the first portion protrudes from a first base portion of the split ring resonator in a direction intersecting the first base portion, The second portion protrudes from a second base portion of the split ring resonator in a direction intersecting the second base portion. The radio wave control structure according to claim 7.

9. A substrate is provided. A radio wave control body, comprising the radio wave control structure according to any one of claims 1 to 8 provided on the substrate.

10. At least two transparent plates are arranged with a gas layer between them, A window material, comprising the radio wave control structure according to any one of claims 1 to 8, provided on a surface of any one of said transparent plates on the side of said gas layer.

Images