Installation method and communication system for radio wave control boards

Abstract

This installation method for a radio wave control plate is for installing a radio wave control plate to be set between a base station and a terminal device. A radio wave control plate provided with a phase gradient in a first direction is installed at a position which is spaced apart from a base station in a second direction orthogonal to a first direction.

Description

Technical Field

[0001] The present disclosure relates to a method for installing a radio wave control board and a communication system.

Background Art

[0002] When performing high-speed communication in a condominium such as an apartment building, a wired connection such as an optical line or FWA (Fixed Wireless Access) using public LTE is used (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The method for installing a radio wave control board of the present disclosure is a method for installing a radio wave control board set between a base station and a terminal device, and installs the radio wave control board provided with a phase gradient in a first direction at a position away from the base station in a second direction perpendicular to the first direction.

[0005] The communication system of the present disclosure includes a base station that transmits radio waves, a radio wave control board that is provided with a phase gradient in a first direction and is installed at a position away from the base station in a second direction perpendicular to the first direction, and receives and refracts the radio waves transmitted by the base station, and a terminal device that receives the radio waves refracted by the radio wave control board.

Brief Description of the Drawings

[0006] [Figure 1] FIG. 1 is a diagram showing a configuration example of a communication system according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing a configuration example of a radio wave control board according to the first embodiment. [Figure 3]Figure 3 is a diagram illustrating the installation method of the radio wave control board according to the first embodiment. [Figure 4] Figure 4 is a diagram illustrating the installation method of the radio wave control board according to the first embodiment. [Figure 5] Figure 5 is a diagram illustrating the installation method of the radio wave control board according to the second embodiment. [Figure 6] Figure 6 is a diagram illustrating the installation method of the radio wave control board according to the second embodiment. [Figure 7] Figure 7 is a diagram illustrating the direction of radio wave refraction of the radio wave control plate according to the third embodiment. [Figure 8] Figure 8 is a diagram illustrating the power of a refracted wave in a comparative example of the third embodiment. [Figure 9] Figure 9 is a diagram illustrating the power of a refracted wave according to the third embodiment. [Figure 10] Figure 10 is a diagram illustrating the installation method of the radio wave control board according to the fourth embodiment. [Figure 11] Figure 11 is a diagram illustrating the installation method of the radio wave control board according to the fourth embodiment. [Figure 12] Figure 12 is a diagram illustrating the received power of the terminal device according to the fourth embodiment. [Figure 13] Figure 13 shows an example of the configuration of a communication system according to the fifth embodiment. [Modes for carrying out the invention]

[0007] Embodiments of the present invention will be described in detail below with reference to the attached drawings. However, this embodiment does not limit the present disclosure, and in the following embodiments, the same parts are denoted by the same reference numerals to omit redundant descriptions.

[0008] In the following explanation, we will establish an XYZ Cartesian coordinate system and describe the positional relationships of each part while referring to this XYZ Cartesian coordinate system. The direction parallel to the X-axis in the horizontal plane will be defined as the X-axis direction, the direction parallel to the Y-axis in the horizontal plane perpendicular to the X-axis will be defined as the Y-axis direction, and the direction parallel to the Z-axis perpendicular to the horizontal plane will be defined as the Z-axis direction. In the following, the X-axis and Y-axis directions are parallel to the ground, and the Z-axis direction is the height direction from the ground. Furthermore, the plane containing the X-axis and Y-axis will be appropriately referred to as the XY plane, the plane containing the X-axis and Z-axis will be appropriately referred to as the XZ plane, and the plane containing the Y-axis and Z-axis will be appropriately referred to as the YZ plane. The XY plane is parallel to the horizontal plane. The XY plane, XZ plane, and YZ plane are orthogonal to each other.

[0009] [First Embodiment] (Communication system) The communication system according to the first embodiment will be described using Figure 1. Figure 1 is a diagram showing an example of the configuration of the communication system according to the first embodiment.

[0010] As shown in Figure 1, the communication system 1 includes a base station 10, a radio wave control board 12, and a terminal device 14. The communication system 1 is a system that performs wireless communication using methods such as 5G (fifth-generation mobile communication system) or 6G (sixth-generation mobile communication system).

[0011] The base station 10 is a wireless communication device configured to communicate wirelessly with the terminal device 14. The base station 10 is configured to communicate wirelessly with the terminal device 14, for example, by transmitting and receiving millimeter waves. In this embodiment, the base station 10 is configured to communicate wirelessly with the terminal device 14 via a radio wave control board 12.

[0012] The radio wave control board 12 is a plate-like member that receives radio waves transmitted by a base station and refracts or reflects them. In the present embodiment, the radio wave control board 12 is configured to refract the radio waves W1 transmitted by the base station 10 and emit them as refracted waves W2 toward the terminal device 14. Specifically, the radio wave control board 12 is configured to refract the radio waves W1 transmitted by the base station 10 installed outdoors and emit refracted waves W2 toward the terminal device 14 installed indoors. The radio wave control board 12 is set, for example, on the wall, veranda, window, etc. of a building. The radio wave control board 12 may be attached to a metal member so that its installation position can be adjusted by, for example, a magnet. The radio wave control board 12 may be installed adjustably, for example, within a resin housing. The radio wave control board 12 may be composed of, for example, a metamaterial that changes the phase of the incident radio waves.

[0013] Using FIG. 2, a configuration example of the radio wave control board according to the first embodiment will be described. FIG. 2 is a diagram showing a configuration example of the radio wave control board according to the first embodiment.

[0014] As shown in FIG. 2, the radio wave control board 12 includes, for example, a substrate 121, a unit structure 122, a unit structure 123, and a unit structure 124. In the example shown in FIG. 2, three types of unit structures, namely the unit structure 122, the unit structure 123, and the unit structure 124, are included, but the present disclosure is not limited thereto.

[0015] The substrate 121 can be, for example, a dielectric substrate formed of a dielectric. The substrate 121 is, for example, rectangular in shape, but is not limited thereto. The substrate 121 may be, for example, circular or a polygon other than rectangular.

[0016] The unit structure 122, the unit structure 123, and the unit structure 124 can be formed on the substrate 121. The unit structure 122, the unit structure 123, and the unit structure 124 can be two-dimensionally arranged on the substrate 121. The unit structure 122, the unit structure 123, and the unit structure 124 can have different sizes respectively. The unit structure 122, the unit structure 123, and the unit structure 124 change the phase of the radio wave incident on the radio wave control plate 12. The unit structure 122, the unit structure 123, and the unit structure 124 can have different frequency bands of the radio wave to be changed and different amounts of phase change respectively.

[0017] FIG. 2 shows an example of the structure of the substrate 121. In the substrate 121, the unit structure 122, the unit structure 123, and the unit structure 124 are provided in order along the X-axis direction. In this example, the radio wave control plate 12 is configured to have a phase gradient along the X-axis direction, but generally the phase gradient also has a component in the Y-axis direction. In the example shown in FIG. 2, the direction of the phase gradient of the radio wave control plate 12 is parallel to the ground, but the present disclosure is not limited thereto. The direction of the phase gradient of the radio wave control plate 12 may be parallel to the ground or may not be parallel to the ground. When the sizes and shapes of the unit structure 122, the unit structure 123, and the unit structure 124 change, the frequency band of the radio wave refracted or reflected by the radio wave control plate 12 and the amount of phase change change.

[0018] In the present embodiment, the direction in which the phase gradient is provided may be referred to as the first direction. The direction in the horizontal plane orthogonal to the first direction may be referred to as the second direction. The direction orthogonal to the first direction and the second direction may be referred to as the third direction.

[0019] The terminal device 14 is a communication device that performs wireless communication with the base station 10 via the radio wave control plate 12. The terminal device 14 receives the radio wave transmitted by the base station 10 via the radio wave control plate 12. The terminal device 14 transmits a radio wave toward the base station 10 via the radio wave control plate 12. The terminal device 14 may be a mobile communication device or a fixed communication device. The terminal device 14 may be, for example, a radio wave relay device or a smartphone or the like.

[0020] (Installation method for radio wave control boards) The installation method of the radio wave control board according to the first embodiment will be explained using Figures 3 and 4. Figures 3 and 4 are diagrams illustrating the installation method of the radio wave control board according to the first embodiment.

[0021] In the following description, the X-axis direction corresponds to the first direction, the Y-axis direction corresponds to the second direction, and the Z-axis direction corresponds to the third direction; however, this disclosure is not limited thereto.

[0022] As shown in Figures 3 and 4, let φ be the half-power angle of the radio wave W1 transmitted by the base station 10, and θ be the refraction angle of the radio wave W1 transmitted by the radio wave control board 12. Furthermore, if the coordinates in the X, Y, and Z directions are (X,Y,Z), then the position coordinates of the base station 10 (the position of the radio wave transmission point) are (0,0,0), the position coordinates of the radio wave control board 12 are (0,Yp,0), and the position coordinates of the terminal device 14 are (Xu,Yu,Zu). That is, the position coordinates of the base station 10 are taken as the origin. The X-axis and Z-axis positions of the base station 10 and the radio wave control board 12 are the same. The radio wave control board 12 is installed at a position away from the base station 10 in the Y-axis direction. That is, the base station 10 and the radio wave control board 12 are installed at the same height from the ground. Note that in the first embodiment, the Z-axis positions of the base station 10 and the radio wave control board 12 are assumed to be the same, but this disclosure is not limited to this. For example, the radio wave control panel 12 only needs to be installed at a position away from the base station 10 in the Y-axis direction. That is, the base station 10 and the radio wave control panel 12 may be installed at different heights from the ground. The same applies to the following. The terminal device 14 is installed within range R1. Range R1 is in the range of θ ± φ / 2 and satisfies the following equation (1).

[0023]

number

[0024] In equation (1), position vector a is (0, Yp, 0) and position vector b is (Xu, Yu - Yp, Zu). In Figures 3 and 4, range R1 is the range in which effective power can be obtained from the refracted wave W2 emitted by the radio wave control board 12. That is, the radio wave control board 12 is installed between the base station 10 and the terminal device 14 so that the terminal device 14 can obtain effective power.

[0025] As described above, in the first embodiment, the radio wave control board 12 is installed at the same height as the base station 10 in a direction perpendicular to the phase gradient, and the radio waves are refracted toward the range R1, thereby allowing the radio waves W1 transmitted by the base station 10 to be properly received by the terminal device 14.

[0026] Furthermore, in the first embodiment, even if the radio wave control board 12 is installed at a different height from the base station 10 in a direction perpendicular to the phase gradient, the radio waves W1 transmitted by the base station 10 can be properly received by the terminal device 14 by satisfying equation (1). In this case, the position coordinates for installing the radio wave control board 12 may be (0, Yp, Zp), the position vector a may be (0, Yp, Zp), and the position vector b may be (Xu, Yu-Yp, Zu-Zp).

[0027] [Second Embodiment] A second embodiment will now be described. In the second embodiment, by considering the direction of the phase gradient of the radio wave control board 12, the radio waves W1 transmitted by the base station 10 can be received more appropriately by the terminal device 14.

[0028] (Installation method for radio wave control boards) The installation method of the radio wave control board according to the second embodiment will be explained using Figures 5 and 6. Figures 5 and 6 are diagrams illustrating the installation method of the radio wave control board according to the second embodiment.

[0029] As shown in Figure 5, in the second embodiment, the radio wave control board 12 is installed at an angle α with respect to the ground 20, which is parallel to the XY plane. That is, by installing the radio wave control board 12 with the direction of its phase gradient tilted relative to the ground 20, the terminal device 14 is installed in a way that allows it to obtain effective power.

[0030] Specifically, let L be the distance between the radio wave control board 12 and the terminal device 14. In this case, the inclination angle α is set to the angle between the straight line 40, which is the intersection of two planes: the plane of the radio wave control board 12 and the planes that pass through the position coordinates of the base station 10, the position coordinates of the radio wave control board 12, and a point inside a sphere 30 with radius Ltan(φ / 2) centered on the position coordinates of the terminal device 14, and the ground. The length of the straight line 40 is Lsinθ.

[0031] As shown in Figure 6, the distance 41 in the X direction from the radio wave control board 12 to the terminal device 14 is Lcosα. The distance 42 in the Z direction from the radio wave control board 12 to the terminal device 14 is Lsinα. In this case, the terminal device 14 is installed such that its position coordinate Xu in the X direction and its position coordinate Zu in the Z direction satisfy the following relationships, equations (2) and (3), respectively.

[0032]

number

[0033]

number

[0034] In the second embodiment, by satisfying equations (2) and (3), the terminal device 14 can obtain effective power more effectively.

[0035] [Third Embodiment] The refraction direction of radio waves in the radio wave control plate according to the third embodiment will be explained using Figure 7. Figure 7 is a diagram illustrating the refraction direction of radio waves in the radio wave control plate according to the third embodiment.

[0036] As shown in Figure 7, the refraction direction of the radio wave W1 transmitted by the base station 10 can be changed by changing the inclination angle α of the phase gradient direction of the radio wave control plate 12 relative to the ground 20. For example, if the phase gradient direction of the radio wave control plate 12 is set horizontally to the ground 20, the radio wave control plate 12 will emit a refracted wave W2 toward position 51. For example, if the phase gradient direction of the radio wave control plate 12 is set inclined in the direction of the arrow, the radio wave control plate 12 will emit a refracted wave W2 toward position 52. By adjusting the inclination angle α, the radio wave control plate 12 can emit a refracted wave W2 toward any position in area 60.

[0037] Figure 8 is a diagram illustrating the power of a refracted wave in a comparative example of the third embodiment. In the comparative example of the third embodiment, the radio wave control plate 12 is configured to refract only one of either horizontal polarization or vertical polarization. When the radio wave control plate 12 refracts only one of horizontal polarization or vertical polarization, there is a problem that the radio wave component in the direction perpendicular to the polarization direction cannot be refracted. For example, as shown in Figure 8, when the radio wave control plate 12 is configured to refract only horizontal polarization, the terminal device 14 can obtain effective power when the refracted wave W2 is emitted toward position 51. However, when the refracted wave W2 is emitted toward position 52, the terminal device 14 may not be able to obtain effective power. As a result, as shown in area 60a, there are positions where effective power can be obtained and positions where effective power cannot be obtained. Therefore, in the third embodiment, the radio wave control plate 12 is made capable of refracting both horizontal and vertical polarization.

[0038] Figure 9 is a diagram illustrating the power of a refracted wave according to the third embodiment. As shown in Figure 9, when the radio wave control plate 12 is configured to refract both horizontal and vertical polarizations, effective power can be obtained at both positions 51 and 52. In this case, the terminal device 14 can obtain effective power at any position in area 60.

[0039] As described above, the third embodiment expands the area in which the terminal device 14 can obtain effective power by configuring the radio wave control board 12 to be able to refract both horizontal and vertical polarizations. As a result, in the third embodiment, the terminal device 14 can obtain effective power regardless of how the radio wave control board 12 is tilted, thus improving the flexibility of the installation of the radio wave control board 12.

[0040] [Fourth Embodiment] A fourth embodiment will now be described. Depending on the shape of the radio wave control board 12, the received power efficiency changes. Therefore, in the fourth embodiment, the shape of the radio wave control board 12 is changed to improve the received power efficiency.

[0041] The installation method of the radio wave control board according to the fourth embodiment will be explained using Figures 10 and 11. Figures 10 and 11 are diagrams for explaining the installation method of the radio wave control board according to the fourth embodiment.

[0042] In the fourth embodiment, the radio wave control board 12 is installed in an area defined based on the positional relationship between the base station 10, the radio wave control board 12, and the terminal device 14. Specifically, the radio wave control board 12 is installed in a circular Fresnel zone 70 defined based on the straight-line distance between the base station 10 and the radio wave control board 12, and the straight-line distance between the radio wave control board 12 and the terminal device 14.

[0043] Within the Fresnel zone 70, regions where radio waves reinforce each other are called odd-order Fresnel zones, and regions where radio waves destructively interfere with each other are called even-order Fresnel zones. Figures 10 and 11 show the first Fresnel zone 71, the second Fresnel zone 72, the third Fresnel zone 73, the fourth Fresnel zone 74, and the fifth Fresnel zone 75. The first Fresnel zone 71, the third Fresnel zone 73, and the fifth Fresnel zone 75 are odd-order Fresnel zones. The second Fresnel zone 72 and the fourth Fresnel zone 74 are even-order Fresnel zones. Figure 10 shows a circular radio wave control board 12A with a diameter of L1. Figure 11 shows a square radio wave control board 12B with a side length of L2.

[0044] Figure 12 is a diagram illustrating the received power of a terminal device according to the fourth embodiment. In Figure 12, the horizontal axis shows the size of one side of the radio wave control plate [m], and the vertical axis shows the received power ratio [dB (decibels)] relative to the received power characteristics when the radio wave control plate 12 is not used in a line of sight. Figure 12 shows a circular radio wave control plate 12A, a rectangular radio wave control plate 12B, and the received power characteristics when the radio wave control plate 12 is not used in a line of sight. In Figure 12, the received power characteristics of the radio wave control plate 12A are shown by a solid waveform, the received power characteristics of the radio wave control plate 12B are shown by a dashed line, and the received power characteristics in a line of sight are shown by a dotted line.

[0045] As shown by the solid waveform, when the diameter L1 (or radius) of the radio wave control plate 12A matches the diameter (or radius) of the even-order Fresnel zone, the received power ratio drops drastically. Therefore, it is preferable to form the radio wave control plate 12A so that its diameter L1 does not match the diameter of the even-order Fresnel zone. Furthermore, the received power characteristics of the radio wave control plate 12A can be improved by forming its diameter L1 to match that of the odd-order Fresnel zone.

[0046] As shown by the dashed waveform, the radio wave control board 12B exhibits a good average received power ratio regardless of the length L2 of one side. Therefore, in the fourth embodiment, it is preferable to configure the radio wave control board in a rectangular shape, as in the radio wave control board 12B. In the fourth embodiment, the shape of the radio wave control board 12B is not limited to a rectangle, and may be configured as a polygon other than a rectangle. When the radio wave control board is configured as a polygon, as in the radio wave control board 12B, it is preferable to install it so as to straddle the odd-order Fresnel zone and the even-order Fresnel zone.

[0047] The radio wave control plate 12B preferably has a length L2 that is greater than the radius of the first Fresnel zone 71. More preferably, the radio wave control plate 12B is formed with a length L2 within the range of twice ± 25% of the radius of the first Fresnel zone 71. In the fourth embodiment, by setting the length L2 of the radio wave control plate 12B to twice ± 25% of the radius of the first Fresnel zone 71, sufficient power can be delivered to the terminal device 14.

[0048] As described above, in the fourth embodiment, by configuring the radio wave control board as a polygon, as in radio wave control board 12B, the received power that the terminal device 14 can obtain can be stabilized. As a result, in the fourth embodiment, the terminal device 14 can receive the radio waves transmitted by the base station 10 more appropriately.

[0049] Furthermore, in the fourth embodiment, the power obtainable by the terminal device 14 can be improved by setting the length L2 of the radio wave control board 12B to twice ±25% of the radius of the first Fresnel zone 71.

[0050] [Fifth Embodiment] A fifth embodiment will be described. If there are multiple terminal devices 14, the radio waves from the base station 10 must be refracted in multiple directions, so there is a possibility that the radio waves cannot be delivered to each of the multiple terminal devices 14.

[0051] An example of the configuration of the communication system according to the fifth embodiment will be described using Figure 13. Figure 13 is a diagram showing an example of the configuration of the communication system according to the fifth embodiment.

[0052] As shown in Figure 13, the communication system 1A includes a base station 10 and radio wave control boards 12-1, 12-2, 12-3, and 12-4. In other words, the communication system 1A includes a plurality of radio wave control boards 12. In the example shown in Figure 13, it is described as including four radio wave control boards 12-1 through 12-4, but the disclosure is not limited thereto.

[0053] Radio wave control panels 12-1 to 12-4 may be installed in a row with a predetermined interval between them. The intervals between each radio wave control panel 12 may be the same or different. Radio wave control panels 12-1 to 12-4 may be installed in a square shape, for example. Radio wave control panels 12-1 to 12-4 may also be installed in a straight line, for example.

[0054] The radio wave control panel 12-1 refracts the radio wave W1 transmitted by the base station 10 and emits the refracted wave W2-1. By changing the angle of the phase gradient direction with respect to the ground, the radio wave control panel 12-1 can emit the refracted wave W2-1 toward the terminal device 14 located in area 60-1.

[0055] The radio wave control panel 12-2 refracts the radio wave W1 transmitted by the base station 10 and emits the refracted wave W2-2. By changing the angle of the phase gradient direction with respect to the ground, the radio wave control panel 12-2 can emit the refracted wave W2-2 toward the terminal device 14 located in area 60-2.

[0056] The radio wave control panel 12-3 refracts the radio wave W1 transmitted by the base station 10 and emits the refracted wave W2-3. By changing the angle of the phase gradient direction with respect to the ground, the radio wave control panel 12-3 can emit the refracted wave W2-3 toward the terminal device 14 located in area 60-3.

[0057] The radio wave control panel 12-4 refracts the radio wave W1 transmitted by the base station 10 and emits the refracted wave W2-4. By changing the phase gradient direction angle with respect to the ground, the radio wave control panel 12-4 can emit the refracted wave W2-4 towards the terminal device 14 located in area 60-4.

[0058] Radio wave control plates 12-1 to 12-4 may each have the same shape or different shapes. Radio wave control plates 12-1 to 12-4 may each have the same or different angles of refraction.

[0059] In other words, radio wave control boards 12-1 to 12-4 are configured to emit radio waves to different areas. That is, in the fifth embodiment, by installing multiple radio wave control boards 12, radio waves can be delivered to a wider area.

[0060] As described above, the fifth embodiment can expand the range over which the radio waves W1 transmitted by the base station 10 are refracted by installing multiple radio wave control boards 12. As a result, the fifth embodiment can allow multiple terminal devices 14 to receive the radio waves W1 transmitted by the base station 10.

[0061] While embodiments of the present disclosure have been described above, the present disclosure is not limited by the content of these embodiments. Furthermore, the aforementioned components include those that are readily conceivable to those skilled in the art, those that are substantially identical, and those that fall within the so-called equivalent range. Moreover, the aforementioned components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the embodiments described above. [Explanation of symbols]

[0062] 1.1A Communication System 10 base station 12 Radio wave control board 14 Terminal devices 70 Fresnel Zone 71. First Fresnel Zone 72. Second Fresnel Zone 73. Third Fresnel Zone 74. Fourth Fresnel Zone 75. Fifth Fresnel Zone

Claims

1. A method for installing a radio wave control board set between a base station and a terminal device, The radio wave control board, which has a phase gradient in the first direction, is installed at a position away from the base station in a second direction perpendicular to the first direction. The refraction angle θ of the radio wave control board satisfies the following equation (1), where the base station's position coordinates are the origin, a is the position vector of the radio wave control board, b is the position vector of the terminal device, and φ is the half-power angle of the radio waves transmitted by the base station. Installation method for radio wave control panels. [Math 1]

2. A method for installing a radio wave control board set between a base station and a terminal device, The radio wave control board, which has a phase gradient in the first direction, is installed at a position away from the base station in a second direction perpendicular to the first direction. When the distance between the terminal device and the radio wave control board is L, the position information of the terminal device in the first direction is Xu, and the position information of the terminal device in the third direction is Zu, the radio wave control board is installed such that the angle α of the radio wave control board in the first direction with respect to the first surface including the first and second directions satisfies the following equations (2) and (3). Installation method for radio wave control panels. [Math 2] [Math 3]

3. The aforementioned radio wave control panel is configured to refract vertically polarized and horizontally polarized radio waves. The method for installing the radio wave control panel according to claim 2.

4. The radio wave control board is formed so as not to coincide with even-order Fresnel zones among a plurality of Fresnel zones defined from the position information of the base station, the radio wave control board, and the terminal device. A method for installing a radio wave control panel as described in claim 3.

5. The aforementioned radio wave control plate is formed in a polygonal shape that spans both even-order Fresnel zones and odd-order Fresnel zones among a plurality of Fresnel zones. A method for installing a radio wave control board as described in claim 4.

6. The area of ​​the aforementioned radio wave control plate is larger than the area of ​​the first Fresnel zone among the multiple Fresnel zones. A method for installing a radio wave control board as described in claim 5.

7. The length of the radio wave control plate in the first direction is 75% to 125% of twice the radius of the first Fresnel zone. A method for installing a radio wave control panel as described in claim 6.

8. Multiple radio wave control boards are installed between the base station and the terminal device. Each of the aforementioned radio wave control boards is formed to receive radio waves transmitted by the base station and refract them in different directions. A method for installing a radio wave control board according to claim 7.

9. A base station that transmits radio waves, A phase gradient is provided in the first direction, and the radio wave control plate is installed at a position away from the base station in a second direction perpendicular to the first direction, and receives and refracts radio waves transmitted by the base station, The aforementioned radio wave control board is used to receive the radio waves that have been refracted by the terminal device, Includes, The refraction angle θ of the radio wave control board satisfies the following equation (4), where the position coordinates of the base station are the origin, the position vector of the radio wave control board is a, the position vector of the terminal device is b, and the half-power angle of the radio wave transmitted by the base station is φ. Communication system. [Math 4]

10. A base station that transmits radio waves, A phase gradient is provided in the first direction, and the radio wave control plate is installed at a position away from the base station in a second direction perpendicular to the first direction, and receives and refracts radio waves transmitted by the base station, The aforementioned radio wave control board is used to receive the radio waves that have been refracted by the terminal device, Includes, When the distance between the terminal device and the radio wave control board is L, the position information of the terminal device in the first direction is Xu, and the position information of the terminal device in the third direction is Zu, the radio wave control board is installed such that the angle α of the radio wave control board in the first direction with respect to the first surface including the first and second directions satisfies the following equations (5) and (6). Communication system. [Math 5] [Math 6]

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