Electromagnetic wave reflecting device, electromagnetic wave reflecting fence, and method for assembling an electromagnetic wave reflecting device

Abstract

The present invention addresses the problem of improving radio wave propagation in mobile body communication both indoors and outdoors. This electromagnetic wave reflection device comprises a panel having a reflection surface that reflects radio waves in a desired band selected from frequency bands of 1-170 GHz, and a support body that supports the panel. The support body has an electroconductive frame, and a non-electroconductive cover that covers at least part of the frame. The frame has a slit for receiving an end part of the panel, and a hollow that is independent of the slit.

Description

[Technical field]

[0001] The present invention relates to an electromagnetic wave reflecting device, an electromagnetic wave reflecting fence, and a method for assembling an electromagnetic wave reflecting device. [Background technology]

[0002] The fifth generation mobile communications system (hereafter referred to as "5G") will expand the available frequency bands, enabling mobile communications with high speed, large capacity, low latency, and the ability to connect multiple devices simultaneously. 5G is expected to be applied not only to public mobile communications networks, but also to traffic control using Internet of Things (IoT) technology, autonomous driving, and industrial IoT such as "smart factories."

[0003] A joining structure for light-transmitting electromagnetic wave shielding plates used in structures such as intelligent buildings has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4892207 Summary of the Invention [Problem to be solved by the invention]

[0005] While 5G is expected to enable high-speed, large-capacity communications, it uses radio waves that tend to travel in a very directional direction, which means that there may be places where the radio waves are difficult to reach. In places where there are many metal machines, such as inside factories, or in places with many buildings where there is a lot of reflection from walls and street trees, a means is required to deliver radio waves to the desired terminal devices and wireless devices. Similar requirements exist in places where there are non-line-of-sight (NLOS) spots where the base station antenna cannot be seen, such as medical facilities, event venues, and large commercial facilities.

[0006] An object of the present invention is to provide an electromagnetic wave reflecting device that improves radio wave transmission in mobile communications both indoors and outdoors. [Means for solving the problem]

[0007] In one aspect of the present disclosure, an electromagnetic wave reflecting device includes: A panel having a reflective surface that reflects radio waves in a desired band selected from a frequency band of 1 GHz to 170 GHz; A support for supporting the panel; Equipped with The support has a conductive frame and a non-conductive cover covering at least a portion of the frame, and the frame has a slit that receives an end of the panel and a hollow independent of the slit. Effect of the Invention

[0008] The electromagnetic wave reflecting device having the above configuration improves radio wave propagation in mobile communications both indoors and outdoors. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of radio wave propagation using an electromagnetic wave reflecting device according to an embodiment. [Figure 2A] FIG. 2 is a diagram illustrating reflection at a reflection angle that is the same as the incident angle. [Figure 2B] 1A and 1B are diagrams illustrating reflection at a reflection angle different from the incident angle. [Figure 2C] FIG. 1 is a diagram illustrating diffusion in multiple directions. [Diagram 3] 1 is a schematic diagram of an electromagnetic wave reflecting device according to an embodiment; [Figure 4] This is a schematic diagram of an electromagnetic wave reflective fence made up of multiple connected panels. [Figure 5A] FIG. 2 is a diagram showing a configuration example of a support body. [Figure 5B] FIG. 13 is a diagram showing another example of the configuration of the support body. [Figure 6A] 1 is an example of a panel configuration. [Figure 6B] 13 is another example of a panel configuration. [Figure 6C] 13 is yet another example of a panel configuration. [Figure 6D] 13 is yet another example of a panel configuration. [Figure 7] FIG. 13 is a diagram showing edge processing of a panel. [Figure 8] 13 is a modified example of an electromagnetic wave reflecting device. [Figure 9A] 13 is another modified example of an electromagnetic wave reflecting device. [Figure 9B] 13 is another modified example of an electromagnetic wave reflecting device. [Figure 9C] This is a modified electromagnetic wave reflective fence made up of multiple connected panels. [Figure 10] FIG. 13 is a diagram illustrating a method for evaluating reflection characteristics. [Figure 11] FIG. 2 is a diagram for explaining an analysis space of reflection characteristics. [Figure 12] FIG. 2 is a diagram for explaining an analysis space of reflection characteristics. [Figure 13A] FIG. 5 is a diagram of a simulation model of the configuration of FIG. 4. [Figure 13B] FIG. 6 is a diagram of a simulation model of the configuration of FIG. 5. [Figure 14] FIG. 13 is a diagram of a simulation model of a comparative example. [Figure 15] FIG. 13 is a diagram showing an analytical structure for evaluating the strength of a support. [Figure 16] FIG. 13 is a diagram showing the results of strength analysis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Overall system image> FIG. 1 is a schematic diagram of radio wave propagation using an electromagnetic wave reflecting device 10 of an embodiment. Radio waves are a type of electromagnetic wave, and generally, electromagnetic waves below 3 THz are called radio waves. In the following, electromagnetic waves radiated from a base station or relay station are called "radio waves," and electromagnetic waves in general are called "electromagnetic waves." In the figure, the same elements are given the same symbols, and duplicated explanations may be omitted.

[0011] The electromagnetic wave reflecting device 10 is disposed in a service area SA provided by a base station BS. The height direction of the space in which radio waves are transmitted and received between the base station BS is defined as the Z direction, and the plane perpendicular to the Z direction is defined as the XY plane. The base station BS is installed indoors or outdoors, and the service area SA can be formed on a street, a shopping mall, a production line in a factory, an event venue, etc.

[0012] The base station BS transmits and receives radio waves in a specific frequency band, for example, in the range of 1 GHz to 170 GHz. The radio waves emitted from the base station BS are reflected, blocked, and weakened by building walls and roadside trees. In factory production lines, the radio waves are reflected, weakened, and blocked by metal equipment, ducts, pipes, and other structures. High-frequency radio waves such as millimeter wave bands tend to travel in a straight line and are less diffracted, so they may have difficulty reaching terminal devices within the service area SA.

[0013] The electromagnetic wave reflecting device 10 has a reflecting surface 105 that reflects radio waves in the 1 GHz to 170 GHz band, and propagates radio waves from the base station BS to terminal devices within the service area SA. The location at which the electromagnetic wave reflecting device 10 is provided is not limited to the example in FIG. 1. The electromagnetic wave reflecting device 10 can be disposed at an appropriate location depending on the location of the base station BS, the surrounding environment, the state within the service area SA, and the like. For example, a plurality of electromagnetic wave reflecting devices 10 may be disposed facing each other with the service area SA in between, or in a staggered arrangement. As will be described later, a plurality of electromagnetic wave reflecting devices may also be coupled together.

[0014] The reflecting surface 105 of the electromagnetic wave reflecting device 10 has at least one of a normal reflector 101 and a metareflector 102. The normal reflector 101 provides a regular reflection of the incident electromagnetic wave with an equal angle of incidence and reflection. The metareflector 102 has an artificial surface that controls the reflection characteristics of the incident electromagnetic wave. A "metareflector" is a type of "metasurface" that means an artificial surface that controls the transmission and reflection characteristics of the incident electromagnetic wave. The metareflector 102 reflects the electromagnetic wave in a specified direction other than regular reflection by controlling the reflection phase distribution and amplitude distribution by arranging a large number of scatterers that are sufficiently small compared to the wavelength. The metareflector 102 not only reflects the electromagnetic wave in a direction other than regular reflection, but also diffuses the electromagnetic wave with a specified angle distribution and forms a wavefront.

[0015] 2A to 2C show the manner of reflection on the reflecting surface 105 of the electromagnetic wave reflecting device 10. In FIG. 2A, the electromagnetic wave incident on the normal reflector 101 is reflected at a reflection angle θref that is the same as the incident angle θin. In FIG. 2B, the electromagnetic wave incident on the metareflector 102a is reflected at a reflection angle θref that is different from the incident angle θin. The absolute value of the difference between the reflection angle θref by the metareflector 102 and the reflection angle by regular reflection may be called the abnormal angle θabn. As described above, by forming a surface impedance by arranging a metal patch or the like that is sufficiently smaller than the wavelength used on the surface of the metareflector 102a, the reflection phase distribution can be controlled and the incident electromagnetic wave can be reflected in a desired direction.

[0016] The electromagnetic wave reflected by the meta-reflector 102 does not have to be a plane wave with a single reflection angle. In FIG. 2C, the surface impedance formed on the surface of the meta-reflector 102b is devised to diffuse the incident electromagnetic wave in multiple directions at multiple different reflection angles. As a method for realizing the reflection in FIG. 2C, for example, there is a method described in PHYSICAL REVIEW B 97, “ARBITRARY BEAM CONTROL USING LOSSLESS METASURFACES ENABLED BY ORTHOGONALLY POLARIZED CUSTOM SURFACE WAVES”. The intensity of the diffused electromagnetic wave may be uniform, or may have a predetermined intensity distribution depending on the reflection direction.

[0017] <Configuration of the electromagnetic wave reflection device and the electromagnetic wave reflection fence> 3 shows a basic configuration of an electromagnetic wave reflecting device 10 according to an embodiment. The electromagnetic wave reflecting device 10 includes a panel 13 having a reflecting surface 105 that reflects radio waves in a desired band selected from a frequency band of 1 GHz to 170 GHz, and a support 11 that supports the panel 13.

[0018] As described above, the reflective surface 105 of the panel 13 is formed of at least one of the normal reflector 101 that reflects light in a regular manner and the meta-reflector 102 that has an artificial surface that controls the reflection characteristics of the incident electromagnetic wave. The normal reflector 101 may include a reflective surface formed of an inorganic conductive material or a conductive polymer material.

[0019] The material, surface shape, and manufacturing method of the metareflector 102 are not important as long as it can reflect the incident electromagnetic wave in a desired direction or diffuse it with a desired angular distribution. In general, a metasurface is obtained by forming a metal patch that is sufficiently smaller than the wavelength to be used on the surface of a conductor such as a metal, with a dielectric layer interposed between them. The metareflector 102 is formed to have the desired reflection characteristics according to the design conditions for the direction in which the electromagnetic wave is to be reflected, and is placed at an appropriate position on the reflecting surface 105.

[0020] The size of the panel 13 may be appropriately designed depending on the environment in which it is used. As an example, the width w of the panel 13 is 0.5 m to 3.0 m, the height h is 1.0 m to 2.5 m, and the thickness t is 3.0 mm to 9.0 mm. Considering the ease of transportation to the installation site of the electromagnetic wave reflecting device 10 and the ease of assembly, the size w×h×t of the panel 13 may be approximately 1.0 m×2.0 m×5.0 mm. A part of the panel 13 may be transparent to visible light.

[0021] The panel 13 is supported by a support 11. The support 11 has a frame 111 having the mechanical strength to stably hold the panel 13. The electromagnetic wave reflecting device 10 may be used alone, or a plurality of electromagnetic wave reflecting devices 10 may be connected together to be used as an electromagnetic wave reflecting fence. In addition to having mechanical strength, the frame 111 has a structure suitable for connecting the reflecting surfaces 105 of the plurality of panels 13. A specific configuration of the frame 111 will be described later with reference to Figures 5A and 5B.

[0022] When the electromagnetic wave reflecting device 10 is installed indoors or outdoors, it may be attached to a wall surface or the like by a support 11. As described below, the support 11 is formed in a light and thin shape while having sufficient strength, and is suitable for installation on a wall surface or the like. The panel 13 and the support 11 are detachable and can be transported separately to the installation site. The electromagnetic wave reflecting device 10 can be assembled at the installation site and then placed in a desired location.

[0023] FIG. 4 is a schematic diagram of an electromagnetic wave reflecting fence 100 in which a plurality of electromagnetic wave reflecting devices 10 are connected. The electromagnetic wave reflecting fence 100 is assembled by connecting a panel 13-1 and a panel 13-2 with a support 11. The support 11 has a frame 111 that holds the ends of the panels 13-1 and 13-2. The frame 111 has a configuration that connects the potential surface of the reflection occurring at the reflecting surface 105 of the panel 13-1 and the potential surface of the reflection occurring at the reflecting surface 105 of the panel 13-2. When the panels 13-1 and 13-2 are connected for use, if the reflected current flowing due to the incidence of the electromagnetic wave is blocked between the adjacent panels 13-1 and 13-2, the energy of the reflected electromagnetic wave is attenuated. In addition, the reflected electromagnetic wave may be radiated in an unnecessary direction, deteriorating the communication quality.

[0024] In order to ensure the continuity of the reflected current between the adjacent panels 13-1 and 13-2, it is desirable that the reference potential of the reflection is transmitted from one panel to the other panel at a high frequency by the support 11, and the reference potential generated by the reflection phenomenon is shared between the adjacent panels. As long as the reference potential of the reflection phenomenon is continuous between the adjacent panels 13-1 and 13-2, the number of panels 13 to be connected is not limited to two, and three or more panels 13 may be connected by the support 11. As described above, each panel 13 and the support 11 are detachable, and may be transported separately and assembled at the installation site to form the electromagnetic wave reflecting fence 100. In that case, the end of the panel located on the outermost side of the multiple continuous panels 13 may be covered with a protective jacket such as plastic instead of the support 11.

[0025] When a plurality of panels 13 are connected, it is desirable that the continuity of the reflected current is as uniform as possible throughout the entire frame 111 of the support 11. A specific example of the configuration of the support 11 will be described below.

[0026] 5A is a schematic diagram showing a configuration example of the support 11A. The support 11A is drawn in a horizontal cross section along the thickness direction of the panel 13 that it supports. The support 11A has a frame 111A formed of a conductor and a non-conductive cover 112A that covers at least a portion of the frame 111A.

[0027] As an example, frame 111A is made of aluminum, which has high electrical conductivity and is lightweight, but may be made of other conductors such as titanium, graphite, conductive carbon compounds, etc. In frame 111A, the direction parallel to reflecting surface 105 of panel 13 to be supported is defined as the width (W) direction, and the direction parallel to the thickness of panel 13 is defined as the thickness (T) direction.

[0028] The horizontal cross section of the frame 111A has a shape of two H-shapes connected in series in the width (W) direction. The frame 111A has slits 113a and 113b on both sides in the width direction to receive the ends of the panel 13, and has a hollow 114 between the slits 113a and 113b that is independent of the slits 113a and 113b. "Independent" from the slits 113a and 113b means that it is not connected to either the slits 113a or 113b. The hollow 114 contributes to reducing the weight of the frame 111A. Hereinafter, the slits 113a and 113b may be simply referred to as "slits 113" without distinguishing between them. The surface on the outside of the inner part in which the hollow 114 and the slits 113a and 113b are formed is defined as the outer surface 116 of the frame 111A.

[0029] The thickness of the frame 111A is set to a thickness that provides sufficient strength to the entire support 11A, as described later. In general, increasing the thickness of the frame 111A increases the rigidity, but if the frame 111A is too thick, it becomes difficult to satisfy the desired electromagnetic wave reflection characteristics and the demand for thinness and light weight. The thickness of the frame 111A is 1.0 mm to 10.0 mm, preferably 1.5 mm to 7.5 mm, and more preferably 2.0 mm to 5.0 mm. In this specification, when a range is expressed by "to", the lower limit and the upper limit are included. By setting the thickness of the frame 111A within the above-mentioned range, the frame 111A can be provided with sufficient rigidity without increasing its size, and the reference potential of reflection can be made common between adjacent panels 13.

[0030] Frame 111A having slits 113a and 113b securely holds the end of panel 13 by surface contact, as described below, and maintains a continuous reflected potential between reflective surface 105 of one panel 13-1 and reflective surface 105 of the other panel 13-2. When a reflected current occurs in one panel 13-1, the reflected current passes through frame 111A and flows into the conductor that constitutes reflective surface 105 of the other panel 13-2. By using frame 111A in the shape of two H-shaped parts arranged in series, the reflected current flows through a short current path, there is little current leakage, and the reflection performance is good.

[0031] The width W of frame 111A is preferably 20 mm to 100 mm, and more preferably 20 mm or more and 60 mm or less, from the viewpoint of reliably holding adjacent panels 13 and making the reflective potential surface common between adjacent panels 13. As an example, the gap G1 between slits 113a and 113b and the gap G1 of hollow 114 are both 5.5 mm.

[0032] The non-conductive cover 112A is made of a non-conductive material that is transparent to the wavelength used. When "transparent" is used, it means that the electromagnetic wave of the target wavelength is transmitted by 50% or more, preferably by 60% or more, and more preferably by 70%. The cover 112A may be made of resin or synthetic resin such as polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), acrylic resin, polyimide (PI), or may be made of fiber-reinforced plastic or other insulating coating. By covering the outer surface 116 of the frame 111A with the non-conductive cover 112A, abnormal scattering at the outer surface of the support 11A can be prevented.

[0033] Both corners of the cover 112A in the width (W) direction may be chamfered with a predetermined radius of curvature R. The cover 112A may be attached to the outer surface 116 of the frame 111A with an adhesive or the like, or may be molded integrally with the frame 111A using a mold. The cover 112A may also be an adhesive layer. The radius of curvature R is, for example, 1 mm or more, preferably 2 mm or more, and more preferably 4 mm or more.

[0034] 5B is a schematic diagram showing a configuration example of the support 11B. The support 11B is drawn in a horizontal cross section along the thickness direction of the panel 13 that it supports. The support 11B has a frame 111B formed of a conductor and a non-conductive cover 112B that covers at least a portion of the frame 111B.

[0035] 5A, frame 111B is made of aluminum, which is highly conductive and lightweight, but may be made of other conductors such as titanium, graphite, conductive carbon compounds, etc. In frame 111B, the direction parallel to reflecting surface 105 of panel 13 to be supported is defined as the width (W) direction, and the direction parallel to the thickness of panel 13 is defined as the thickness (T) direction.

[0036] Frame 111B has a horizontal cross-sectional shape of two H-shapes connected in series in the width (W) direction, similar to frame 111A, but has wings 115 extending outward from slits 113a and 113b at both ends in the width (W) direction. Hollow 114 formed in the center of frame 111B contributes to reducing the weight of frame 111B. As an example, gap G1 between slits 113a and 113b is 5.5 mm, and gap G2 of hollow 114 is 6.0 mm. The thickness of frame 111B including wings 115 is 1.0 mm to 5.5 mm, preferably 2.0 mm to 5.0 mm. Providing wings 115 on frame 111B increases the rigidity of frame 111B compared to the configuration of FIG. 5A, improving the mechanical strength of support 11B as a whole. Furthermore, because the rigidity is ensured by the wings 115, the gap G2 of the hollow 114 is wider than that of the frame 111A in FIG. 5A.

[0037] Non-conductive cover 112B covers outer surface 116 between a pair of wings 115 extending on both sides of frame 111B in the width (W) direction. Corners of frame 111B from which the wings stand may be chamfered with a predetermined radius of curvature R. In this case, corners of cover 112B disposed between wings 115 are also chamfered with the same radius of curvature R. In the configuration of FIG. 5B, adhesion can be improved whether non-conductive cover 112B and frame 111B are attached with an adhesive or the like or cover 112B and frame 111B are integrally molded. Cover 112B itself may be an adhesive layer.

[0038] Both the support 11A in FIG. 5A and the support 11B in FIG. 5B grip the ends of the panel 13 with slits 113 formed in the frame 111, thereby supporting the panel 13 with sufficient strength and making the reflected current or reference potential for reflection common between adjacent panels.

[0039] 6A to 6D show examples of the configuration of panel 13. In Fig. 6A, panel 13A has reflective surface 105 of conductor 131. Reflective surface 105 may have any configuration as long as it is a surface that reflects electromagnetic waves of 1 GHz to 170 GHz. As an example, reflective surface 105 may be formed of a mesh conductor, a conductive film, a combination of transparent resin and a conductive film, or the like that reflects electromagnetic waves of any frequency band selected from the range of 1 GHz to 170 GHz.

[0040] By designing the reflecting surface 105 to be capable of reflecting radio waves in a desired frequency band from 1 GHz to 170 GHz, it is possible to cover the 1.5 GHz band, 2.5 GHz band, etc., which are the main frequency bands currently used in mobile communications in Japan. In the next-generation 5G communication network, the 4.5 GHz band, 28 GHz band, etc. are planned. In foreign countries, the 2.5 GHz band, 3.5 GHz band, 4.5 GHz band, 24 to 28 GHz band, 39 GHz band, etc. are planned as 5G frequency bands. It is also possible to support 52.6 GHz, which is the upper limit of the millimeter wave band frequency band of the 5G standard. In the future, if indoor mobile communications in the terahertz band are realized, the reflection band of the reflecting surface 105 may be extended to the terahertz band by applying photonic crystal technology, etc.

[0041] The conductor 131 does not have to be a homogeneous conductor film as long as it can reflect 30% or more of radio waves in the range of 1 GHz to 170 GHz. For example, it may be a mesh or lattice formed to a density that reflects electromagnetic waves in the above frequency band, or it may be a hole arrangement. The repetition pitch associated with the density that reflects the desired electromagnetic waves may be a uniform period or may be non-uniform. The repetition period or its average period is preferably 1 / 5 or less of the wavelength of the target frequency, and more preferably 1 / 10 or less.

[0042] 6B shows an example of the configuration of panel 13B. Panel 13B is a normal reflector and has a laminated structure of conductor 131 and dielectric 132 that is transparent to the operating frequency. One of the surfaces of conductor 131 becomes reflecting surface 105. When an electromagnetic wave is incident from the conductor 131 side, the interface between conductor 131 and air becomes reflecting surface 105. When an electromagnetic wave is incident from the dielectric 132 side, the interface between conductor 131 and dielectric 132 becomes reflecting surface 105.

[0043] It is desirable that the dielectric 132 that holds the conductor 131 or covers the surface of the conductor 131 has a rigidity that can withstand vibration and satisfies the safety requirements of ISO014120 of the International Organization for Standardization (ISO). When used outdoors or in a factory, it is desirable that it can withstand and protect against impacts even if an object hits it. It is also preferable that it is transparent in the visible light range. As an example, optical plastic, reinforced plastic, reinforced glass, etc. that have a certain level of strength or more are used. As optical plastic, polycarbonate (PC), polymethyl methacrylate (PMMA), polystyrene (PS), etc. may be used.

[0044] Fig. 6C shows an example of the configuration of panel 13C. Panel 13C has conductor 131 sandwiched between dielectric 132 and dielectric 133. Depending on the incident direction of the electromagnetic wave, the interface between conductor 131 and any of the dielectrics becomes reflecting surface 105. The rigidity required for dielectrics 132 and 133 is the same as that of the configuration of Fig. 6B.

[0045] FIG. 6D shows an example of the configuration of a panel 13D. A meta-reflector 102 may be provided in a part of the laminate of FIG. 6B. A laminate of a conductor 131 and a dielectric 132 may be used as a normal reflector 101. The meta-reflector 102 may be fixed to the surface of the dielectric 132 of the normal reflector 101 by bonding or the like. A region of a three-layer structure of the conductor 131, the dielectric 132, and the meta-reflector 102 may be an asymmetric reflection region AS that forms a metasurface. A region of a two-layer structure of the conductor 131 and the dielectric 132 without the meta-reflector 102 may be a symmetric reflection region SY that provides regular reflection.

[0046] When the panels 13A to 13D of FIGS. 6A to 6D are held by the supports 11A or 11B, the conductors 131 are electrically connected to the frames 111A or 111B, and the reflected potential is transmitted to the adjacent panel 13.

[0047] FIG. 7 shows an example of the treatment of the conductor 131 at the end of the panel 13. In FIG. 7, the configuration of the panel 13C in FIG. 6C is used, but the treatment is also applicable to the panel 13B in FIG. 6B and the panel 13D in FIG. 6D. The conductor 131 may be drawn outward from the end of the dielectric 132 and folded back at the end of the panel 13 to cover a part of the surface of at least one of the dielectrics 132. When the end of the panel 13 is inserted into the slit 113 of the frame 111 of the support 11, the folded back portion 131a of the conductor 131 comes into surface contact with the inner wall of the slit 113. By drawing the conductor 131 to the surface of the panel 13 at the folded back portion 131a, the contact area between the conductor 131 and the slit 113 is increased, and the electrical connection is stabilized.

[0048] Fig. 8 shows an electromagnetic wave reflecting device 10A as a modified example of the electromagnetic wave reflecting device 10. The electromagnetic wave reflecting device 10A has a meta-reflector 102 that is movable on the panel 13. The meta-reflector 102 may be incorporated into the panel 13D integrally with the normal reflector 101 as shown in Fig. 6D, or may be configured to be movable on the reflecting surface 105 as shown in Fig. 8.

[0049] The configuration for varying the position of the meta-reflector 102 on the reflecting surface 105 may be any configuration as long as it suppresses interference between the meta-reflector 102 and the reflecting surface 105. As one example, the rod 16 for holding the meta-reflector 102 may be attached to the panel 13 so as to be slidable in the horizontal direction, and the position of the meta-reflector 102 may be held on the rod 16 so as to be movable in the vertical direction.

[0050] The rod 16 may be made of a non-metallic material with a low dielectric constant that does not interfere with the reflection characteristics of the normal reflector 101 or the meta-reflector 102. The rod 16 may be designed so that optical and mechanical interference at the panel interface is zero or minimal. The meta-reflector 102 can be moved to an optimal position on the panel 13 depending on the environment of the site where the electromagnetic wave reflecting device 10A is installed, the positional relationship with the base station BS, and the like. The support 11 has slits 113a and 113b and a hollow 114, as in FIG. 5A or FIG. 5B, and can transmit the reference potential of the reflection phenomenon occurring on the reflection surface 105 to the reflection surface of the adjacent panel 13.

[0051] 9A shows an electromagnetic wave reflecting device 10B as another modified example of the electromagnetic wave reflecting device 10. The electromagnetic wave reflecting device 10B is a free-standing type. The electromagnetic wave reflecting device 10B has a panel 13 having a reflecting surface 105 and a support 12 that supports the panel 13.

[0052] The support 12 has a base 122 and a pillar 121 extending vertically from the base 122. The cross-sectional shape of the pillar 121 cut along a plane parallel to the XY plane is as shown in Fig. 5A or 5B. The pillar 121 has a frame 111 having a slit 113 and a hollow 114, and a non-conductive cover 112 covering at least a part of the outer surface 116 of the frame 111.

[0053] In the electromagnetic wave reflecting device 10B as well, the panel 13 and the support 12 can be separated, and the device can be assembled at the installation site. During assembly, the end of the panel 13 is inserted into the slit 113 of the support 12 and the device is made to stand on the installation surface. Since the electromagnetic wave reflecting device 10B is self-supporting, it can be placed in any desired location, indoors or outdoors, and can also be used as a partition, fence, etc., with a radio wave reflecting function.

[0054] 9A, in the case of a free-standing electromagnetic wave reflecting device 10B, in order to reinforce the strength of the panel 13, a brace may be provided on the surface of the panel 13 opposite the reflecting surface 105. The brace may be placed diagonally between the supports 12 that hold both ends of the panel 13. Alternatively, a reinforcing beam may be provided at the upper end or lower end of the panel 13.

[0055] 9B shows an electromagnetic wave reflecting device 10C as yet another modified example of the electromagnetic wave reflecting device 10. The electromagnetic wave reflecting device 10C is free-standing as in FIG. 9A, and the support 12 has a base 122 and a pillar 121 extending from the base 122. The pillar 121 has a frame 111 that holds the end of the panel 13.

[0056] A meta-reflector 102 is movably provided on a panel 13. The moving structure of the meta-reflector 102 may have any configuration as long as it does not interfere with the reflecting surface 105. Here, similar to Fig. 8, a rod 16 that can move in the horizontal direction indicated by a double arrow is used on the panel 13, and the meta-reflector 102 is attached to the rod 16 so as to be movable in the vertical direction (Z direction). By selecting the position of the meta-reflector 102 on the panel 13 according to the surrounding environment, the position of the asymmetric reflection area AS (see Fig. 6D) can be adjusted.

[0057] FIG. 9C shows an electromagnetic wave reflecting fence 100A, which is a modified example of the electromagnetic wave reflecting fence. The electromagnetic wave reflecting fence 100A has a configuration in which a plurality of electromagnetic wave reflecting devices 10B are connected to each other, and the panel 13-1 and the panel 13-2 are connected by the support 12. The support 12 stands the panels 13-1 and 13-2 almost vertically from XY by the base 122. The frame 111 of the pillar 121 holds the ends of the panels 13-1 and 13-2, and connects the potential surface of the reflection occurring on the reflecting surface 105 of the panel 13-1 to the potential surface of the reflection occurring on the reflecting surface 105 of the panel 13-2. Instead of the electromagnetic wave reflecting device 10B, the electromagnetic wave reflecting fence may be formed by connecting the electromagnetic wave reflecting devices 10C of FIG. 9B. In either case, the panel 13 and the support 12 can be transported separately and the fence can be assembled at the installation site. When the electromagnetic wave reflecting device 10C is used, the position of the meta-reflector 102 may be determined during or after assembly of the electromagnetic wave reflecting fence.

[0058] In the configuration of Fig. 9C, one or both of the panels 13-1 and 13-2 may be provided with reinforcing braces, reinforcing beams, etc. By making a plurality of continuous panels self-supporting, they can be used as partitions for event venues, security fences for production lines, etc.

[0059] <Evaluation of the support> The reflection characteristics of the support 11 (including the support 12) are evaluated below. The reflection characteristics are evaluated by the peak ratio of the scattering cross section. The peak ratio is expressed as the ratio of the peak intensity of the scattering cross section when the frame 111 is used to the peak intensity of the scattering cross section of a single panel without the frame 111.

[0060] FIG. 10 is a diagram for explaining a method for evaluating reflection characteristics. The ability to reflect incident electromagnetic waves is evaluated by the radar cross section (RCS), that is, the scattering cross section. The unit of RCS is decibel square meter (dBsm). By electrically connecting two panels with a conductive frame 111, the main peak intensity of the RCS is reduced compared to a single panel. The peak ratio is the main peak intensity of the RCS when the frame 111 is used (indicated as "connected" in the figure) relative to the main peak intensity of the RCS of a single panel (indicated as "not connected" in the figure). The higher the peak ratio, the less the reduction in peak intensity and the better the reflection characteristics. The peak ratio is 0.4 or more, preferably 0.5 or more, more preferably 0.6 or more, and even more preferably 0.7 or more. In the evaluation, a plane wave of a predetermined frequency is reflected by the panel surface using general-purpose three-dimensional electromagnetic field simulation software, and the scattering cross section is analyzed.

[0061] 11 and 12 are diagrams for explaining the analysis space of the reflection characteristics of the embodiment and the comparative example described below. In FIG. 11 and FIG. 12, the thickness direction of the panel 13 is the x direction, the width direction is the y direction, and the height direction is the z direction, and the analysis space is expressed as (size in the x direction)×(size in the y direction)×(size in the z direction). The size of the analysis space when the frequency is 2 to 15 GHz is 150 mm×500 mm×500 mm. The size of the analysis space when the frequency is 28 GHz is 100 mm×200 mm×200 mm. The analysis space is made smaller at high frequencies because the wavelength becomes shorter. As shown in FIG. 12, the boundary condition is designed to arrange electromagnetic wave absorbers around the analysis space.

[0062] 13A and 13B are diagrams of a simulation model used in the embodiment. FIG. 13A corresponds to the support 11A in FIG. 5A, and FIG. 13B corresponds to the support 11B in FIG. 5B. The panel 13 is configured by sandwiching a conductor 131 between two dielectrics 132 and 133 and bonding them together. In an actual panel, a conductor mesh is used as the conductor 131, and the end portion of the mesh may be folded back as shown in FIG. 7, but in the simulation model, the conductor 131 is simply sandwiched between two dielectrics 132. In both FIG. 5A and FIG. 5B, polycarbonate having a thickness of 2.5 mm is used as the dielectrics 132 and 133, and SUS is used as the conductor 131 between the two polycarbonates. The total thickness t of the panel 13 is 1.5 mm. PNL is 5.0 mm.

[0063] In FIG. 5A, the frame 111A is made of aluminum and has a thickness t FRM is 5.0 mm, and the width W is 60 mm. The slit interval t SLIT The width W of the hollow 114 is 5.5 mm. GAP The thickness of the non-conductive cover 112A is 20 mm, and the gap G1 is 5.5 mm. The distance d between the slits in the width direction is 30 mm. That is, an aluminum wall having a thickness of 5 mm is present between the hollow 114 and the slit. The non-conductive cover 112A is made of PVC and has a thickness t PVC 5.0 mm, and the radius of curvature R of the edge of cover 112A is 2 mm.

[0064] In FIG. 5B, the frame 111B is made of aluminum, and the total thickness of the frame 111 including the wings 115 is t FRM The height h of the fins 115 protruding from both sides of the frame 111B in the width direction is 5.0 mm, and the width W is 60 mm. WING The slit spacing t is 5.0 mm. SLIT is 5.5 mm, the gap G2 of the hollow 114 is 6.0 mm, and the width W of the hollow 114 is GAP The width of the slits is 20 mm, and the distance d between the slits in the width direction is 30 mm. As in FIG. 5A, there is an aluminum wall with a thickness of 5 mm between the hollow 114 and the slits. The non-conductive cover 112B disposed between the vanes 115 is PVC, and its thickness t PVCThe thickness of the cover 112B is 5 mm and the width is 50 mm. The radius of curvature R of the inner edge of the cover 112B is 2 mm.

[0065] Using the simulation model of FIGS. 13A and 13B, the reflection characteristics are evaluated by changing the frequency of the incident electromagnetic wave. EXAMPLES

[0066] The configuration shown in FIG. 13A is used, that is, a PVC cover 112A having a thickness of 5.0 mm and a width of 60 mm is placed on the outside of an aluminum frame 111A having a thickness of 5.0 mm, a width of 60 mm, a gap G1 of the hollow 114 of 5.5 mm, and a width of the hollow 114 of 20 mm. The edge of the cover 112A is chamfered with a radius of curvature R2 mm. An electromagnetic wave with a frequency of 3.8 GHz is incident on the panel 13, and the main peak of the RCS (scattering cross section) is calculated while changing the incident angle from 0° to 60° in 10° increments. The incident angle of 0° is perpendicular to the panel surface. The peak ratio is calculated using the RCS main peak calculated for each incident angle and the RCS main peak for each incident angle of a single panel obtained in advance. The calculation results are shown in Table 1.

[0067] [Table 1] The configuration of FIG. 13A exhibits a high peak ratio of 0.83 or more over the incidence angles from 0° to 60° for 3.8 GHz electromagnetic waves. EXAMPLES

[0068] The configuration shown in Fig. 13B is used, that is, a PVC cover 112B is placed on the outside of a frame 111B with wings 115, and a gap G2 of the hollow 114 is 6.0 mm. An electromagnetic wave with a frequency of 3.8 GHz is incident on the panel 13, and the main peak of the RCS (scattering cross section) is calculated while changing the incident angle from 0° to 60° in 10° increments, and the peak ratio to the PCS main peak for a single panel is calculated. The calculation results are shown in Table 2.

[0069] [Table 2] The configuration of FIG. 13B exhibits a high peak ratio of 0.78 or more over the incidence angles from 0° to 60° for 3.8 GHz electromagnetic waves. EXAMPLES

[0070] In Example 3, the frequency of the incident electromagnetic wave is changed to 28 GHz in the configuration of Figure 13A. The incident angle of the 28 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 3.

[0071] [Table 3] The configuration of Fig. 13A shows a peak ratio of 0.53 or more in the range of 0° to 40° for 28GHz electromagnetic waves. The reason why the peak ratio drops beyond 50° is thought to be because, depending on the incidence angle and frequency of the electromagnetic wave, the reflected wave when the surface wave propagates through the PVC cover 112A attached to the aluminum frame 111A and is radiated from the end point acts in a direction that weakens the reflected wave by the panel, that is, it becomes a destructive reflection. Since the phase of the reflected wave when the surface wave propagates through the PVC and is radiated from the end point depends on the dielectric constant and thickness of the PVC, the width and frequency of the frame 111A, the drop in the peak ratio when the incidence angle is large can be solved by selecting another insulating material according to the target frequency and frame structure (including size). EXAMPLES

[0072] In Example 4, the frequency of the incident electromagnetic wave is changed to 28 GHz in the configuration of Figure 13B. The incident angle of the 28 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 4.

[0073] [Table 4] The configuration in Fig. 13B shows a peak ratio of 0.44 or more in the range of 0° to 40° for 28 GHz electromagnetic waves. The reason why the peak ratio drops beyond 50° is thought to be that, as in Example 3, depending on the incidence angle and frequency of the electromagnetic waves, the reflected wave from the panel and the reflected wave propagating on the surface of the PVC and radiated from the end point may destructively interfere with each other. Because the wings 115 are provided on the frame 111B, the drop in reflection characteristics at incidence angles of 50° or more is smaller than in Example 3. EXAMPLES

[0074] In Example 5, the frequency of the incident electromagnetic wave is changed to 24 GHz in the configuration of Figure 13A. The incident angle of the 24 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 5.

[0075] [Table 5] The configuration in Figure 13A shows a high peak ratio of 0.82 or more for 24 GHz electromagnetic waves in the range of 0° to 30°, and a peak ratio of 0.71 is obtained even at 60°. Although the peak ratio decreases at 40° and 50°, the reflection characteristics are good overall. EXAMPLES

[0076] In Example 6, the frequency of the incident electromagnetic wave is changed to 24 GHz in the configuration of Figure 13B. The incident angle of the 24 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 6.

[0077] [Table 6] 13B shows a high peak ratio of 0.77 or more in the range of 0° to 30° for 24 Hz electromagnetic waves. The peak ratio drops between 40° and 60°, but good reflection characteristics can be exhibited in an environment where the light is incident on the panel at an angle of 40° or more, preferably 30° or more. EXAMPLES

[0078] In Example 7, the frequency of the incident electromagnetic wave is changed to 26 GHz in the configuration of Figure 13A. The incident angle of the 26 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 7.

[0079] [Table 7] The configuration in Figure 13A shows a peak ratio of 0.42 or more for 26 GHz electromagnetic waves in the range of 0° to 40°. The peak ratio drops off at 50° and 60°, but the reflection characteristics are generally within an acceptable range. EXAMPLES

[0080] In Example 8, the frequency of the incident electromagnetic wave is changed to 26 GHz in the configuration of Figure 13B. The incident angle of the 26 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 8.

[0081] [Table 8] The configuration in Figure 13B shows a peak ratio of 0.40 or more in the range of 0° to 40° for a 26 Hz electromagnetic wave. The peak ratio drops off at 50° and 60°, but the reflection characteristics are generally within an acceptable range.

[0082] <Evaluation of Comparative Examples> FIG. 14 is a diagram of a simulation model of a comparative example. In the comparative example, an H-shaped aluminum frame without a hollow is used. The width W of the frame is fixed at 50 mm, and the thickness t VARIED is changed in the range of 10 mm to 30 mm. By changing the thickness, the total thickness at the center of the frame also changes. The distance d between the slits in the width direction is 20 mm. The depth and interval of the slits and the configuration of the panel 13 are the same as those in the simulation models of Figs. 13A and 13B. The reflection characteristics are evaluated based on the peak ratio, as in Examples 1 to 8.

[0083] <Comparative Example 1> In Comparative Example 1, the aluminum frame has a thickness of 10 mm and a width W of 50 mm. The frame thickness of 10 mm is the combined thickness of the aluminum frame 111 and the PVC cover 112 in Examples 1 to 8. The frequency of the incident electromagnetic wave is set to 3.8 GHz. The incident angle of the 3.8 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 9.

[0084] [Table 9] The configuration of Comparative Example 1 exhibits a peak ratio of 0.65 or more over the range of 0° to 60° for electromagnetic waves of 3.8 GHz. However, the reflection characteristics are inferior to the results of Example 1 (Table 1) and Example 2 (Table 2) for electromagnetic waves of the same frequency (3.8 GHz).

[0085] <Comparative Example 2> In Comparative Example 2, the thickness of the aluminum frame is 20 mm, and the width W is 50 mm. As in Comparative Example 1, the incident angle of the 3.8 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 10.

[0086] [Table 10] The configuration of Comparative Example 2 shows a peak ratio of 0.58 or more over the range of 0° to 60° for electromagnetic waves of 3.8 GHz. However, compared with the results of Example 1 (Table 1) and Example 2 (Table 2) for electromagnetic waves of the same frequency (3.8 GHz), the reflection characteristics are inferior. It is considered that the attenuation of the incident electromagnetic waves is slightly larger than that of Comparative Example 1 because the thickness of the aluminum frame is doubled.

[0087] <Comparative Example 3> In Comparative Example 3, the thickness of the aluminum frame is 30 mm, and the width W is 50 mm. As in Comparative Examples 1 and 2, the incident angle of the 3.8 GHz electromagnetic wave is changed in 10° increments from 0° to 60°, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 11.

[0088] [Table 11] The configuration of Comparative Example 3 shows a peak ratio of 0.61 or more over the range of 0° to 60° for electromagnetic waves of 3.8 GHz. However, compared to the results of Example 1 (Table 1) and Example 2 (Table 2) for electromagnetic waves of the same frequency (3.8 GHz), the reflection characteristics are inferior. The peak ratio is larger at some incident angles compared to Comparative Examples 1 and 2, probably because the frame thickness is set to 30 mm, which approaches 1 / 2 the wavelength of the incident electromagnetic wave, and the electromagnetic waves reinforce each other at some incident angles, increasing the RCS peak intensity.

[0089] <Comparative Example 4> In Comparative Example 4, the thickness of the aluminum frame is 10 mm, and the width W is 50 mm. The frequency of the incident electromagnetic wave is changed to 28 GHz. The incident angle of the 28 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 12.

[0090] [Table 12] A peak ratio of 0.46 was obtained for perpendicular incidence, and a peak ratio of 0.63 was obtained for an incidence angle of 50°, but the other peak ratios were low, and the reflection characteristics were inferior to those of Example 3 (Table 3) and Example 4 (Table 4) for incident electromagnetic waves of the same frequency (28 GHz). The reason why the peak ratio is high at an incidence angle of 50° is thought to be that when the thickness of the aluminum frame is 10 mm, it is close to the wavelength of the incident electromagnetic wave of 28 GHz, and depending on the incidence angle, the incident electromagnetic waves interfere with each other and strengthen each other, resulting in a high RCS peak intensity.

[0091] <Comparative Example 5> In Comparative Example 5, the thickness of the aluminum frame is 20 mm, and the width W is 50 mm. As in Comparative Example 4, the incident angle of the 28 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 13.

[0092] [Table 13] A peak ratio of 0.59 was obtained when the incident angle was 30°, but the other peak ratios were low, and the reflection characteristics were inferior to those of Example 3 (Table 3) and Example 4 (Table 4) for incident electromagnetic waves of the same frequency (28 GHz).

[0093] <Comparative Example 6> In Comparative Example 6, the thickness of the aluminum frame is 30 mm, and the width W is 50 mm. As in Comparative Examples 4 and 5, the incident angle of the 28 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 14.

[0094] [Table 14] A peak ratio of 0.55 was obtained when the incident angle was 20°, but the other peak ratios were low, and the reflection characteristics were inferior to those of Example 3 (Table 3) and Example 4 (Table 4) for incident electromagnetic waves of the same frequency (28 GHz).

[0095] <Comparative Example 7> In Comparative Example 7, the thickness of the aluminum frame is 10 mm, and the width W is 50 mm. The frequency of the incident electromagnetic wave is changed to 24 GHz. The incident angle of the 28 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 15.

[0096] [Table 15] A peak ratio of 0.44 or more was obtained in the incident angle range of 0° to 40°, but the reflection characteristics were inferior to those of Example 5 (Table 5) and Example 6 (Table 6) for incident electromagnetic waves of the same frequency (24 GHz).

[0097] <Comparative Example 8> In Comparative Example 8, the thickness of the aluminum frame is 20 mm, and the width W is 50 mm. As in Comparative Example 7, the incident angle of the 24 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 16.

[0098] [Table 16] A peak ratio of 0.6 or more was obtained when the incident angle was 0° to 20°, and the peak ratio was 1.12 when the incident angle was perpendicular. Looking only at the peak ratios at 0° and 10°, the peak ratios are higher than those of Example 5 (Table 5) and Example 6 (Table 6) for incident electromagnetic waves of the same frequency (24 GHz), but when looking at the entire range of 0° to 60°, the reflection characteristics of Example 5 and Example 6 are better.

[0099] <Comparative Example 9> In Comparative Example 9, the thickness of the aluminum frame is 30 mm, and the width W is 50 mm. As in Comparative Examples 7 and 8, the incident angle of the 24 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 17.

[0100] [Table 17] Although a peak ratio of 0.43 or more was barely obtained at incident angles of 20° and 30°, the other peak ratios were low, and the reflection characteristics were inferior to those of Example 5 (Table 5) and Example 6 (Table 6) for incident electromagnetic waves of the same frequency (24 GHz).

[0101] <Comparative Example 10> In Comparative Example 10, the thickness of the aluminum frame is 10 mm, and the width W is 50 mm. The frequency of the incident electromagnetic wave is changed to 26 GHz. The incident angle of the 26 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 18.

[0102] [Table 18] A peak ratio of 0.43 or more was obtained in the incident angle range of 30° to 50°, but when looking at the entire range of 0° to 60°, the reflection characteristics of Example 7 (Table 7) and Example 8 (Table 8) for incident electromagnetic waves of the same frequency (26 GHz) are better.

[0103] <Comparative Example 11> In Comparative Example 11, the thickness of the aluminum frame is 20 mm, and the width W is 50 mm. As in Comparative Example 10, the incident angle of the 24 GHz electromagnetic wave is changed from 0° to 60° in 10° increments, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 19.

[0104] [Table 19] A peak ratio of 0.49 or more was obtained at an incident angle of 0° to 40°, but when looking at the entire range of 0° to 60°, the reflection characteristics of Example 7 (Table 7) and Example 8 (Table 8) for incident electromagnetic waves of the same frequency (26 GHz) are better.

[0105] <Comparative Example 12> In Comparative Example 12, the thickness of the aluminum frame is 30 mm, and the width W is 50 mm. As in Comparative Examples 10 and 11, the incident angle of the 26 GHz electromagnetic wave is changed in 10° increments from 0° to 60°, and the intensity ratio of the main peak of the scattering cross section is calculated. The calculation results are shown in Table 20.

[0106] [Table 20] High peak ratios are obtained at incident angles of 0° and 10°, but the peak ratios at other angles are low. Looking at the entire range of 0° to 60°, the reflection characteristics of Example 7 (Table 7) and Example 8 (Table 8) for incident electromagnetic waves of the same frequency (24 GHz) are more stable.

[0107] From the above results, the reflection characteristics of the embodiment are better than those of the comparative example. In the simulation results for frequencies of 24 GHz, 26 GHz, and 28 GHz, the peak ratio of the comparative example is higher depending on the incident angle. This is thought to be because the reflected wave emitted at the end point of the surface wave propagated on the PVC surface in the embodiment may act destructively on the reflected wave on the panel surface. On the other hand, it is thought that the reflection may be enhanced by resonating with the wavelength of the incident electromagnetic wave depending on the thickness of the aluminum frame in the comparative example.

[0108] <Frame strength analysis> Next, the frame structure of the embodiment will be considered from the viewpoint of frame strength or rigidity. Fig. 15 shows an analytical structure model used for strength analysis. Throughout analytical structures 1 to 3, the frame width is set to 60 mm.

[0109] Analytical structure 1 in Figure 15(A) is a reference structure, which is an H-shaped aluminum frame with no hollow. The slit interval is 5.5 mm, the thickness of the frame where the slits are formed is 1 mm, and the width of the central part, i.e., the distance between the slits on both sides, is 10 mm.

[0110] The analytical structure 2 in Fig. 15(B) corresponds to the frame 111A used in the support 11A in Fig. 5A. The thickness of the frame is 5 mm, the distance between the slits on both sides and the hollow is 5.5 mm, the depth of the slit is 15 mm, the width of the hollow is 20 mm, and the distance between the slits is 30 mm.

[0111] The analytical structure 3 in Fig. 15(C) corresponds to the frame 111B used in the support 11B in Fig. 5B. The thickness of the frame is 5 mm, the spacing between the slits on both sides is 5.5 mm, the depth of the slits is 15 mm, the hollow spacing is 6.0 mm, the width is 20 mm, the distance between the slits is 30 mm, and the height of the wings extending outward from the slits is 5 mm.

[0112] The analysis conditions are as follows: Fixed method: Both ends of the beam are fixed, and a load is concentrated at the center to calculate the deflection δ at the center. Beam length L: 2000mm Load F: Apply two loads: 50 kg and 90 kg. Young's modulus (E) of material (Al): 72000MPz Density ρ:2.7×10 -6 Kg / mm 3 Cross-sectional area A: Depends on structure Moment of inertia I: Depends on structure Section modulus Z [cm 3 ]:Depends on the structure Here, the length L of the beam is the length when both ends of the entire length of the frame 111 in the height h direction (see FIG. 3) are fixed.

[0113] The section modulus Z represents the degree of bending strength of the cross section of the member, and the larger the value, the greater the bending strength of the cross section. Based on the above parameters, the deflection due to the applied load δ1 and the deflection due to the weight δ2 are calculated.

[0114] δ1=(F×L3) / (192×E×I) δ2=(w×L4) / (384×E×I) Here, w is the weight of the component, which is calculated by multiplying density ρ, gravity g, and cross-sectional area A (ρ×g×A). Deflection δ is the sum of δ1 and δ2 (δ=δ1+δ2). The smaller the deflection, the stronger the rigidity and mechanical strength.

[0115] Figure 16 shows the analysis results of the frame strength. When the load was both 50 kg and 90 kg, the amount of deflection of analytical structures 2 and 3 of the embodiment was very small compared to analytical structure 1, which is a comparative example. In addition, the hollow structure contributes to weight reduction.

[0116] 16, it is seen that the cross-sectional bending strength and rigidity of the support 11 of the embodiment are sufficiently high compared to the reference structure, the mechanical strength is excellent, and the support 11 can stably hold the panel 13. Furthermore, as can be seen from the evaluation of the reflection characteristics described above, the support 11 of the embodiment exhibits stable reflection characteristics for incident electromagnetic waves in the 3.8 GHz band and 24 to 27 GHz over an incidence angle range of 0° to 60°.

[0117] The electromagnetic wave reflecting device 10 using the support 11 of the embodiment has excellent reflection characteristics and is structurally stable, and can be used indoors and outdoors. The electromagnetic wave reflecting device of the embodiment can be used as a wall material, partition, fence, etc., indoors and outdoors. It is applied to the inner walls of buildings such as factories, the outer walls of buildings, soundproof walls on highways, wall materials for warehouses and parking lots, partitions in factories, construction sites, agricultural fences, nursing homes, medical sites, event venues, commercial facilities, offices, etc.

[0118] Each electromagnetic wave reflecting device 10 may be transported with the supports 11 attached to both sides of the panel 13 as shown in FIG. 3, or the panel 13 and the supports 11 may be transported separately and assembled at the installation site. As shown in FIG. 4, an electromagnetic wave reflecting fence 100 in which a plurality of panels 13 are connected may be transported with the panels 13 and the supports 11 separately, or may be transported with the supports 11 attached to one end of the panel 13 and the other end covered with a protective jacket or the like. In either case, it can be assembled at the site. Also, as shown in FIG. 8 and FIG. 9B, the positioning of the meta-reflector 102 on the panel 13 may be performed at the installation site of the electromagnetic wave reflecting device 10. The configuration of the meta-reflector 102 movable on the surface of the panel 13 may be applied to an electromagnetic wave reflecting fence 100A using a free-standing support 12.

[0119] The shape and dimensions of the support 11 are not limited to the examples shown in the embodiments, and may be designed appropriately according to the size, weight, installation environment, etc. of the panel, as long as the mechanical strength of the frame is maintained and the reference potential of reflection on the reflective surface is continuous.

[0120] This application claims priority to Patent Application No. 2021-042117, filed with the Japan Patent Office on March 16, 2021, the entire contents of which are incorporated by reference. [Explanation of symbols]

[0121] 10, 10A~10C electromagnetic wave reflector 100, 100A Electromagnetic Wave Reflecting Fence 11, 11A, 11B, 12 Support 111, 111A, 111B Frames 112, 112A, 112B Cover 113, 113a, 113b Slit 114 Hollow 115 birds 116 Outer surface 121 Pillar 122 Base Panels 13, 13-1, and 13-2 16 Rod 101 Normal reflector 102 Metal Reflector 105 Reflective surface 131 Conductor 132, 133 Dielectrics BS base station SA Service Area SY Symmetrical reflection area AS Asymmetric reflection area

Claims

1. A panel having a reflective surface that reflects radio waves in a desired band selected from a frequency band of 1 GHz to 170 GHz; A support for supporting the panel; Equipped with The support has a conductive frame and a non-conductive cover covering at least a part of the frame, the frame having a slit for receiving an end of the panel and a hollow independent of the slit. Electromagnetic wave reflector.

2. The frame has a first slit and a second slit on both sides in a width direction, and the hollow is between the first slit and the second slit.

2. The electromagnetic wave reflecting device according to claim 1.

3. The frame has wings extending toward the outside of the slit at the ends in the width direction.

3. The electromagnetic wave reflecting device according to claim 1 or 2.

4. The cover covers at least a portion of an outer surface of the frame.

4. The electromagnetic wave reflecting device according to claim 1.

5. The cover is disposed between the blades provided on both sides of the slit in the width direction.

4. The electromagnetic wave reflecting device according to claim 3.

6. The cover is a resin or adhesive layer that is transparent to the wavelength used.

6. The electromagnetic wave reflecting device according to claim 1.

7. The support has a base and a pillar extending vertically from the base, the pillar is formed by the frame and the cover, The panel stands upright relative to the installation surface by the support.

7. The electromagnetic wave reflecting device according to claim 1.

8. An electromagnetic wave reflecting fence comprising a plurality of electromagnetic wave reflecting devices according to any one of claims 1 to 7 connected by the support body.

9. A first panel having a first reflective surface that reflects radio waves in a desired band selected from a frequency band of 1 GHz to 170 GHz and a second panel having a second reflective surface that reflects radio waves in the desired band are mechanically connected by a support having a non-conductive cover on its surface; a conductive frame provided on the inside of the non-conductive cover of the support to provide continuity of a reference potential of reflection between the first reflecting surface and the second reflecting surface; A method for assembling an electromagnetic wave reflecting device.

10. At least one of the first panel and the second panel has a metasurface with controlled reflection characteristics on the first reflecting surface or the second reflecting surface, positioning the metasurface on a panel at the installation site of the electromagnetic wave reflecting device; A method for assembling the electromagnetic wave reflecting device according to claim 9.

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