Radio wave control device and radio wave control method

Abstract

This radio wave control device comprises a housing, a radio wave control plate which is disposed inside the housing and which controls the emission direction of waves received from a base station, and a rotation mechanism which is disposed inside the housing and which rotates the radio wave control plate within a first plane.

Description

Radio wave control device and radio wave control method

[0001] The present disclosure relates to a radio wave control device and a radio wave control method.

[0002] There are known techniques for controlling electromagnetic waves without using a dielectric lens. For example, Patent Document 1 describes a technique for refracting radio waves by changing the parameters of each element in a structure in which resonator elements are arranged.

[0003] JP 2015-231182 A

[0004] The radio wave control device of the present disclosure comprises a housing, a radio wave control plate installed within the housing that controls the emission direction of an incident wave received from a base station, and a rotation mechanism installed within the housing that rotates the radio wave control plate within a first plane.

[0005] The radio wave control method disclosed herein includes a step of controlling the emission direction of an incident wave received from a base station using a radio wave control plate installed within a housing, and a step of rotating the radio wave control plate within a first plane to control the emission direction.

[0006] FIG. 1 is a diagram for explaining an outline of a wireless communication system according to a first embodiment. FIG. 2 is a diagram showing the configuration of a radio wave control device according to the first embodiment. FIG. 3A is a diagram showing an example of the configuration of a polygonal housing according to a first example of the first embodiment. FIG. 3B is a diagram showing an example of the configuration of a polygonal housing according to a second example of the first embodiment. FIG. 3C is a diagram showing an example of the configuration of a polygonal housing according to a third example of the first embodiment. FIG. 4 is a diagram schematically showing an example of a radio wave control plate. FIG. 5A is a diagram showing an example of the configuration of a radio wave control plate according to the first embodiment. FIG. 5B is a diagram showing an example of the configuration of a radio wave control plate according to the first embodiment. FIG. 5C is a diagram showing an example of the configuration of a radio wave control plate according to the first embodiment. FIG. 6 is a schematic diagram showing an example of the configuration of a radio wave control plate according to a second embodiment. FIG. 7 is a diagram for explaining a method of fixing a radio wave control plate according to the second embodiment to a rotating base. FIG. 8 is a diagram for explaining a method of rotating a rotation mechanism according to a first example of the second embodiment from outside the housing. FIG. 9 is a diagram showing an example of the configuration of a rotation mechanism according to a second example of the second embodiment. FIG. 10 is a diagram showing an example of the configuration of a rotation mechanism according to a third example of the second embodiment. FIG. 11 is a diagram illustrating a coverage area according to a comparative example of the third embodiment. FIG. 12 is a diagram illustrating a coverage area according to the third embodiment. FIG. 13 is a diagram illustrating a method for installing a radio wave control plate according to a comparative example of the fourth embodiment. FIG. 14 is a diagram illustrating a method for installing a radio wave control plate according to the fourth embodiment. FIG. 15A is a diagram illustrating a configuration example of a radio wave control plate according to a first example of the fifth embodiment. FIG. 15B is a diagram illustrating a configuration example of a radio wave control plate according to a second example of the fifth embodiment. FIG. 16 is a diagram illustrating a configuration example of a radio wave control device according to the sixth embodiment. FIG. 17A is a diagram illustrating a phase distribution of a first radio wave control plate according to the sixth embodiment. FIG. 17B is a diagram illustrating a phase distribution of a second radio wave control plate according to the sixth embodiment. FIG. 18A is a diagram illustrating an example of a superposition phase distribution according to the sixth embodiment. FIG. 18B is a diagram illustrating an example of a superposition phase distribution according to the sixth embodiment. FIG. 19 is a diagram illustrating a method for changing the focal position of radio waves according to the sixth embodiment.

[0007] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to this embodiment, and in the following embodiments, the same components are designated by the same reference numerals, and redundant explanations will be omitted.

[0008] In the following description, an XYZ Cartesian coordinate system is set, and the positional relationship of each part will be described with reference to this XYZ Cartesian coordinate system. The direction parallel to the X axis in a horizontal plane is defined as the X-axis direction, the direction parallel to the Y axis in the horizontal plane perpendicular to the X axis is defined as the Y-axis direction, and the direction parallel to the Z axis perpendicular to the horizontal plane is defined as the Z-axis direction. Furthermore, the plane including the X axis and Y axis will be appropriately referred to as the XY plane, the plane including the X axis and Z axis will be appropriately referred to as the XZ plane, and the plane including 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, the XZ plane, and the YZ plane are perpendicular to each other.

[0009] [First embodiment] (Wireless communication system) An outline of a wireless communication system according to a first embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram for explaining an outline of a wireless communication system according to the first embodiment.

[0010] 1 , the wireless communication system 1 includes a base station 2, a terminal 3, and a radio wave control board 4. If an obstacle 5 exists between the base station 2 and the terminal 3, the radio waves transmitted from the base station 2 to the terminal 3 are blocked by the obstacle 5. In an environment where the obstacle 5 blocking the radio waves between the base station 2 and the terminal 3 exists, the wireless communication system 1 causes the radio wave control board 4 to reflect or refract the radio waves from the base station 2, allowing the terminal 3 to receive the radio waves.

[0011] Here, if radio wave control board 4 is, for example, a radio wave control board that cannot electrically control the reflection or refraction direction of radio waves, a change in the positional relationship between terminal 3 and radio wave control board 4 may result in communication being lost between base station 2 and terminal 3. Therefore, in the present disclosure, the radio wave control board is installed inside a housing, and the reflection or refraction direction of radio waves is changed by rotating the radio wave control board inside the housing.

[0012] (Radio wave control device) An example of the configuration of the radio wave control device according to the first embodiment will be described with reference to Fig. 2. Fig. 2 is a diagram showing the configuration of the radio wave control device according to the first embodiment.

[0013] 2, the radio wave control device 10 includes a housing 12 and a radio wave control plate 14. The radio wave control plate 14 is disposed inside the housing 12. The radio wave control plate 14 is rotatable within the XY plane inside the housing 12.

[0014] The housing 12 is a box-like body in which the radio wave control plate 14 can be installed. The housing 12 is made of a material with a low dielectric constant that is permeable to radio waves. The housing 12 is preferably made of a resin that is permeable to radio waves. Examples of resins that make up the housing 12 include, but are not limited to, ABS resin, polycarbonate resin, polyethylene resin, acrylic resin, and Teflon (registered trademark) resin. The housing 12 is preferably formed in the shape of a regular polygon or a circle when viewed in the Z-axis direction.

[0015] 3A is a diagram showing a configuration example of a polygonal housing according to a first example of the first embodiment. As shown in FIG. 3A, the housing 12 according to the first example of the first embodiment is configured to be rectangular when viewed from the Z-axis direction. The housing 12 may, for example, be provided with a connecting portion that can be connected to other housings 12. As a result, in the first example of the first embodiment, four housings 12, namely housing 12-1, housing 12-2, housing 12-3, and housing 12-4, can be connected.

[0016] 3B is a diagram showing a configuration example of a polygonal housing according to a second example of the first embodiment. As shown in FIG. 3B, the housing 12A according to the second example of the first embodiment is configured to be hexagonal when viewed from the Z-axis direction. The housing 12A may, for example, be provided with a connecting portion that can be connected to other housings 12A. As a result, in the second example of the first embodiment, four housings 12A, namely housings 12A-1, 12A-2, 12A-3, and 12A-4, can be connected.

[0017] 3C is a diagram showing a configuration example of a polygonal housing according to a third example of the first embodiment. As shown in FIG. 3C, the housing 12B according to the third example of the first embodiment is configured to be octagonal when viewed from the Z-axis direction. The housing 12B may, for example, be provided with a connecting portion that can be connected to other housings 12B. As a result, in the third example of the first embodiment, four housings 12B, namely housings 12B-1, 12B-2, 12B-3, and 12B-4, can be connected.

[0018] Returning to FIG. 2 , the radio wave control plate 14 is installed inside the housing 12. The radio wave control plate 14 can be placed inside the housing 12, for example, by opening any one side of the housing 12. The radio wave control plate 14 is a plate-shaped member configured to be able to transmit or reflect radio waves transmitted from the base station 2. The radio wave control plate 14 includes a radio wave refraction plate that refracts radio waves in a predetermined direction and a radio wave reflection plate that reflects radio waves in a predetermined direction. When the radio wave control plate 14 receives radio waves transmitted from the base station 2, it refracts or reflects the radio waves toward the terminal and emits them toward the terminal. The radio wave control plate 14 can be configured, for example, with a metamaterial that changes the phase of the incident wave.

[0019] Fig. 4 is a diagram schematically illustrating an example of the radio wave control board 14. As shown in Fig. 4, the radio wave control board 14 may include, for example, a substrate 20, an element 22, an element 24, an element 26, and an element 28.

[0020] The elements 22, 24, 26, and 28 may be formed on the substrate 20. The substrate 20 may have, for example, a rectangular shape, but is not limited to this. The elements 22, 24, 26, and 28 may be two-dimensionally arranged on the substrate 20. Specifically, in FIG. 2 , a plurality of elements 22 may be arranged in a row on the bottom row of the substrate 20. A plurality of elements 24 may be arranged in a row on the row above the row on which the elements 22 are arranged on the substrate 20. A plurality of elements 26 may be arranged in a row on the row above the row on which the elements 24 are arranged on the substrate 20. A plurality of elements 28 may be arranged in a row on the row above the row on which the elements 26 are arranged on the substrate 20. In other words, the radio wave control plate 14 may have a structure in which a plurality of elements of different sizes are periodically arranged. The elements 22 to 28 may each vary in the frequency band and the amount of phase change of the radio waves they change. Each of elements 22 to 28 has a rectangular shape, but is not limited to this. By changing the size and shape of elements 22, 24, 26, and 28, it is possible to adjust the frequency band and the amount of phase change of the radio waves to be refracted or reflected.

[0021] 2, the radio wave control plate 14 is configured to have, for example, a rectangular shape when viewed in the Z-axis direction. Preferably, the radio wave control plate 14 is configured to have a polygonal shape when viewed in the Z-axis direction.

[0022] 5A, 5B, and 5C are diagrams showing examples of the configuration of a radio wave control plate according to the first embodiment. As shown in FIG. 5A, the radio wave control plate 14A may be circular when viewed in the Z-axis direction. As shown in FIG. 5B, the radio wave control plate 14B may be hexagonal when viewed in the Z-axis direction. As shown in FIG. 5C, the radio wave control plate 14C may be octagonal when viewed in the Z-axis direction.

[0023] One method for rotating radio wave control plate 14 is to open housing 12, remove radio wave control plate 14, rotate housing 12 so that it is oriented to reflect or refract radio waves in the desired direction, and then install it back inside housing 12. In this way, in the first embodiment, the reflection and refraction directions of radio waves, whose directivity is determined at the time of design, can be easily changed. Also, in the first embodiment, radio wave control plate 14 may be disposed at an angle with respect to the XY plane.

[0024] Second Embodiment (Radio Wave Control Device) A second embodiment of the present disclosure will be described below. Fig. 6 is a schematic diagram showing a configuration example of a radio wave control plate according to the second embodiment.

[0025] 6, the radio wave control device 10A includes a housing 12, a radio wave control plate 14, and a rotation mechanism 16. The radio wave control plate 14 and the rotation mechanism 16 are disposed in the housing 12. The radio wave control device 10 is configured such that the radio wave control plate 14 can be rotated within the XY plane by the rotation mechanism 16.

[0026] The rotation mechanism 16 includes a rotation table 16a and a shaft 16b. The rotation table 16a is, for example, a flat plate formed in a circular shape when viewed from the Z-axis direction. The shaft 16b is a shaft provided at the center of the rotation table 16a. The rotation mechanism 16 rotates the rotation table 16a along the XY plane around the shaft 16b in the direction of the arrow. The rotation mechanism 16 is installed inside the housing 12 so that the XY plane can be rotated by a user's operation from outside the housing 12. The rotation mechanism 16 is installed inside the housing 12 so that the XY plane can be rotated by, for example, inserting the shaft 16b into the bottom surface 12a of the housing 12.

[0027] The radio wave control plate 14 is installed on a rotating base 16a. Specifically, the radio wave control plate 14 is fixed to the rotating base 16a so as not to move on the rotation mechanism 16. Fig. 7 is a diagram for explaining a method for fixing a radio wave control plate 14D according to the second embodiment to the rotating base 16a. As shown in Fig. 7, the radio wave control plate 14D has a plurality of cutout portions 14a.

[0028] The cutout portion 14a is a portion obtained by cutting out a portion of the periphery of the substrate of the radio wave control plate 14D. The cutout portion 14a can be connected to a protrusion (not shown) formed on the rotating base 16a. By connecting the cutout portion 14a to the protrusion (not shown) formed on the rotating base 16a, the radio wave control plate 14D is fixed to the rotating base 16a.

[0029] FIG. 8 is a diagram illustrating a method for rotating the rotation mechanism 16 according to the first example of the second embodiment from outside the housing 12. FIG. 8 shows the bottom surface 12a of the housing 12 on which the rotation mechanism 16 is installed, as viewed from the outside. As shown in FIG. 8, a hole 12ab is formed in the bottom surface 12a, and a shaft 16b of the rotation mechanism 16 installed inside the housing 12 is exposed through the hole 12ab. A marker M is provided around the hole 12ab. The marker M is provided by, for example, laser engraving. The marker M is an arrow indicating the rotation direction of the rotation mechanism 16. A user can rotate the rotation table 16a along the XY plane by rotating the shaft 16b in the direction of the arrow indicated by the marker M.

[0030] 9 is a diagram showing a configuration example of a rotation mechanism according to a second example of the second embodiment. As shown in Fig. 9, in the rotation mechanism 16A, the substrate of the radio wave control plate 14E is formed in the shape of a gear with multiple teeth formed on the outer periphery.

[0031] Rotation mechanism 16A has a shaft portion 30 provided on the side surface of housing 12 and a tooth portion 32 provided inside housing 12. Shaft portion 30 and tooth portion 32 are connected to each other. Tooth portion 32 meshes with teeth on the outer periphery of radio wave control plate 14E.

[0032] Rotation mechanism 16A is configured so that when a user rotates shaft portion 30 in the direction of arrow V1, tooth portion 32 rotates in the direction of arrow V2. Because tooth portion 32 meshes with the teeth on the outer periphery of radio wave control plate 14E, when tooth portion 32 rotates in the direction of arrow V2, radio wave control plate 14E rotates in the direction of arrow V3. In other words, by rotating shaft portion 30 in the direction of arrow V1, a user can rotate radio wave control plate 14E in the direction of arrow V3.

[0033] FIG. 10 is a diagram illustrating a configuration example of a rotation mechanism according to a third example of the second embodiment. As shown in FIG. 10 , in the rotation mechanism 16B, the substrate of the radio wave control plate 14F has multiple teeth formed on its outer periphery, and the outer periphery is formed in the shape of a constant-width figure, which is a constant-width curve. A constant-width curve is a closed curve whose width across the entire length is constant, and examples thereof include a circle and a Reuleaux polygon. In the example shown in FIG. 10 , the substrate of the radio wave control plate 14F has multiple teeth formed on its outer periphery, and is formed in the shape of a Reuleaux triangle. The substrate of the radio wave control plate 14F is not limited to a Reuleaux triangle, and may be formed in the shape of a Reuleaux polygon.

[0034] The rotation mechanism 16B has a shaft portion 30 provided on the side surface of the housing 12, a teeth portion 32 provided inside the housing 12, and a conveyor 34 provided along the inner wall of the housing 12 and having a plurality of teeth formed on its inner circumference. The teeth of the radio wave control plate 14F mesh with the teeth of the conveyor 34. The teeth portion 32 mesh with the teeth of the conveyor 34.

[0035] The rotation mechanism 16B is configured so that when a user rotates the shaft 30 in the direction of arrow V1, the teeth 32 rotate in the direction of arrow V2. Because the teeth 32 and the teeth of the conveyor 34 mesh, when the teeth 32 rotate in the direction of arrow V2, the conveyor 34 rotates along the inner periphery of the housing 12 as shown by arrows V5 and V6. Because the teeth of the conveyor 34 and the teeth of the radio wave control plate 14F mesh, the rotation of the conveyor 34 as shown by arrows V5 and V6 causes the radio wave control plate 14F to rotate in the direction of arrow V7. In other words, by rotating the shaft 30 in the direction of arrow V1, the user can rotate the radio wave control plate 14F in the direction of arrow V7.

[0036] As described above, in the second embodiment, the radio wave control plate installed inside the housing can be rotated from outside the housing, and the second embodiment makes it possible to easily change the reflection and refraction directions of radio waves, the directionality of which is determined at the time of design.

[0037] [Third Embodiment] A third embodiment of the present disclosure will be described. When controlling the radio wave reception area by rotating a radio wave control plate installed in a housing to change the reflection direction or refraction direction, if the refraction angle or reflection angle is small relative to the beam width of the radio waves, a problem occurs in that the reception area cannot be changed effectively. For example, the beam width is defined as the range of the beam over which the radio waves emitted from the radio wave control plate are half their maximum power at the distance between the radio wave control plate and the terminal or base station.

[0038] FIG. 11 is a diagram illustrating a receivable area according to a comparative example of the third embodiment. FIG. 11 schematically illustrates the refraction of radio waves W1 incident on radio wave control plate 14. In FIG. 11 , the distance between radio wave control plate 14 and a terminal or base station is d, the refraction angle of the radio waves is θ1, and the beam width of radio waves W1 at a position at distance d from radio wave control plate 14 where the gain drops by 3 dB is w. In this case, d·tan θ1 is distance L1, and w / 2·cos θ1 is distance L2. The example shown in FIG. 11 illustrates a case where the refraction angle θ1 is small relative to the beam width w, satisfying the condition d·tan θ1<w / 2·cos θ1. In this case, the area in which radio waves W2 from radio wave control plate 14 can be received is area A1. Area A1 is a circular ring-shaped area when viewed from the Z-axis direction.

[0039] FIG. 12 is a diagram illustrating a receivable area according to the third embodiment. FIG. 12 schematically illustrates the refraction of radio waves W1 incident on radio wave control plate 14. In FIG. 12, the distance between radio wave control plate 14 and the terminal is d, the refraction angle of the radio waves is θ2, and the beam width of radio waves W1 at a position at distance d from radio wave control plate 14 where the gain drops by 3 dB is w. In this case, d·tan θ2 is distance L3, and w / 2·cos θ2 is distance L4. The example shown in FIG. 12 illustrates a case where the refraction angle θ2 is large relative to the beam width w, satisfying the condition d·tan θ2≧w / 2·cos θ2. In this case, the area in which radio waves W2 from radio wave control plate 14 can be received is area A2. Area A2 is a circular ring-shaped range when viewed from the Z-axis direction.

[0040] Comparing area A1 shown in Fig. 11 with area A2 shown in Fig. 12, area A2 is larger. In other words, if the refraction angle or reflection angle of the radio waves from radio wave control board 14 is θ, the receivable area can be changed effectively by satisfying the condition d tan θ ≥ w / 2 cos θ.

[0041] [Fourth embodiment] A fourth embodiment of the present disclosure will be described. When radio waves are refracted by a radio wave control plate installed inside a housing, if the radio wave control plate is installed at an angle to the base station, the effective area in the direction of radio wave refraction may become smaller when the radio wave control plate rotates, which may result in a decrease in received power.

[0042] Fig. 13 is a diagram for explaining a method of installing a radio wave control board according to a comparative example of the fourth embodiment. Fig. 13 schematically shows how radio waves from base station 50 are refracted and emitted. Arrow V10 indicates the direction connecting base station 50 and the center of radio wave control board 14. Arrow V11 indicates the normal direction of radio wave control board 14.

[0043] As shown in step S1, radio wave control board 14 is installed so that the angle formed by arrows V10 and V11 is installation angle α. Radio wave control board 14 is configured to refract radio waves W1 from the base station and emit radio waves W2. The refraction angle of radio waves W1 is θ3. Installation angle α is greater than refraction angle θ3.

[0044] In step S2, radio wave control plate 14 is rotated 180°. That is, radio wave control plate 14 is reversed left and right. As shown in Fig. 13, when radio wave control plate 14 is reversed left and right, the emission direction of radio wave W2 is also reversed. Because radio wave control plate 14 is tilted with respect to base station 50, when the emission direction of radio wave W2 is reversed, the effective area in the refraction direction of radio wave W1 becomes smaller, which may result in a decrease in received power.

[0045] Fig. 14 is a diagram for explaining a method of installing a radio wave control board according to the fourth embodiment. Fig. 14 schematically shows how radio waves from a base station 50 are refracted and emitted. Arrow V10 indicates the direction connecting the base station 50 and the center of radio wave control board 14. Arrow V11 indicates the normal direction of radio wave control board 14.

[0046] As shown in step S11, radio wave control plate 14 is installed so that arrow V10 and arrow V11 are aligned. That is, the installation angle formed by arrow V10 and arrow V11 is 0°. That is, in the fourth embodiment, installation angle α is smaller than refraction angle θ3.

[0047] In step S12, radio wave control plate 14 is rotated 180 degrees to reverse the left and right of radio wave control plate 14. As shown in Fig. 14, when radio wave control plate 14 is reversed, the emission direction of radio wave W2 is also reversed. Because radio wave control plate 14 is not tilted with respect to base station 50, the received power does not decrease even if the emission direction of radio wave W2 is reversed.

[0048] That is, it is preferable to install radio wave control plate 14 so that the angle formed by the line connecting base station 50 and the center of radio wave control plate 14 and the normal to radio wave control plate 14 is smaller than the refraction angle of radio wave control plate 14. It is more preferable that the angle formed by the line connecting the center of radio wave control plate 14 and the normal to radio wave control plate 14 is 0°. As a result, the fourth embodiment can suppress a decrease in reception sensitivity caused by rotating radio wave control plate 14.

[0049] [Fifth Embodiment] A fifth embodiment of the present disclosure will be described. Reducing the size of the radio wave control plate is advantageous for rotating the radio wave control plate within the housing. However, reducing the size of the radio wave control plate results in a problem of reduced reception power. However, if the size of the radio wave control plate is increased in order to improve reception power, it may become impossible to rotate the radio wave control plate within the housing.

[0050] In the fifth embodiment, the surface shape of the radio wave control plate is a constant width curve, that is, a constant width figure, thereby improving the received power.

[0051] 15A is a diagram showing an example of the configuration of a radio wave control plate according to a first example of the fifth embodiment. As shown in FIG. 15A, when the housing 12C is circular when viewed in the Z-axis direction, the shape of the radio wave control plate 14A is preferably circular when viewed in the Z-axis direction. When the housing 12C is circular when viewed in the Z-axis direction, the shape of the radio wave control plate may be a Reuleaux polygon when viewed in the Z-axis direction.

[0052] 15B is a diagram showing an example of the configuration of a radio wave control plate according to a second example of the fifth embodiment. As shown in FIG. 15B, when the housing 12 has a polygonal shape such as a rectangle when viewed from the Z-axis direction, the shape of the radio wave control plate 14G may be a Reuleaux triangle when viewed from the Z-axis direction. When the housing 12 has a polygonal shape such as a rectangle when viewed from the Z-axis direction, the shape of the radio wave control plate may be a circle or a Reuleaux polygon other than a Reuleaux triangle when viewed from the Z-axis direction.

[0053] For example, if the shape of the housing 12 as viewed in the Z-axis direction is a square with a side length of L, when a radio wave control plate that is square as viewed in the Z-axis direction is installed and rotated, the length of one side must be L / (√2). In this case, the area of ​​the radio wave control plate is (L^2) / 2.

[0054] On the other hand, when the shape of the housing 12 as viewed in the Z-axis direction is a square with a side length of L, if a radio wave control plate that is circular as viewed in the Z-axis direction is installed and rotated, the length of the diameter can be L. In this case, the area of ​​the radio wave control plate is (π / 4)L^2.

[0055] That is, the area ratio between a rotatable square radio wave control plate and a circular radio wave control plate within the same size housing 12 is: Area of ​​square radio wave control plate: Area of ​​circular radio wave control plate = 2:π. When converted to gain under far-field conditions, the circular radio wave control plate has a higher gain than the square radio wave control plate by about 2.0 dB. When converted to received power, the circular radio wave control plate has 1.6 times higher received power than the square radio wave control plate.

[0056] Furthermore, when viewed from the Z-axis direction, if the shape of the housing 12 as viewed from the Z-axis direction is a square with a side length of L, the shape of the radio wave control plate that has the smallest area among constant width curves that can rotate inside the housing 12 is a Reuleaux triangle. The area ratio of a rotatable square radio wave control plate to a circular radio wave control plate within the same size housing 12 is: Area of ​​square radio wave control plate: Area of ​​circular radio wave control plate = 1:1.41. Converting this to gain under far-field conditions, the Reuleaux triangular radio wave control plate has a higher gain than the square radio wave control plate by about 1.5 dB. Converting this to received power, the Reuleaux triangular radio wave control plate has 1.4 times higher power than the square radio wave control plate.

[0057] That is, in the fifth embodiment, by making the surface shape of the radio wave control plate a constant width curve, it is possible to increase the gain of received power at a distance by 1.5 dB or more.

[0058] Sixth Embodiment A sixth embodiment of the present disclosure will be described. When a radio wave control plate with a constant-width curved surface shape is rotated and used inside a housing, there is a problem in that it is difficult to adjust the focal position when it is desired to concentrate power at a specific point. Examples of cases where it is desired to concentrate power at a specific point include, but are not limited to, cases where it is desired to compensate for power loss due to a medium such as heat-reflecting glass by converging radio waves. In the sixth embodiment, the phase distribution of the radio wave control plate is configured to be concentric, and the focal length is made variable by making the phase distribution variable. Furthermore, in the sixth embodiment, a mechanism is provided that allows the focal position to be changed by rotating the radio wave control plate while shifting the center of the concentric phase distribution from the center of rotation.

[0059] Fig. 16 illustrates an example of the configuration of a radio wave control device according to the sixth embodiment. Fig. 16 is a diagram illustrating an example of the configuration of a radio wave control device according to the sixth embodiment.

[0060] FIG. 16 is a schematic diagram of a radio wave control device 10B according to a sixth embodiment. As shown in FIG. 16, the radio wave control device 10B includes a housing 12, a first radio wave control plate 14H-1, and a second radio wave control plate 14H-2. That is, the radio wave control device 10B includes multiple radio wave control plates. The first radio wave control plate 14H-1 and the second radio wave control plate 14H-2 are arranged one on top of the other along the Z-axis direction. The radio wave control device 10B includes a rotation mechanism (not shown) that can independently rotate the first radio wave control plate 14H-1 and the radio wave control plate 14H-2 within the XY plane. Examples of the rotation mechanism that can be used include, but are not limited to, the rotation mechanism 16 shown in FIG. 6, the rotation mechanism 16A shown in FIG. 9, and the rotation mechanism 16B shown in FIG. 10.

[0061] The radio wave control device 10B changes the focal length using the principle of a moire lens by independently rotating two radio wave control plates, the first radio wave control plate 14H-1 and the second radio wave control plate 14H-2, in the XY plane.

[0062] The phase distribution of the radio wave control plate according to the sixth embodiment will be described with reference to Fig. 17A and Fig. 17B. Fig. 17A is a diagram for explaining the phase distribution of the first radio wave control plate according to the sixth embodiment. Fig. 17B is a diagram for explaining the phase distribution of the second radio wave control plate according to the sixth embodiment.

[0063] Fig. 17A shows the phase distribution of the first radio wave control board 14H-1. In Fig. 17A, the shade of color indicates the amount of phase change. For example, the darker the color, the greater the amount of phase change, and the lighter the color, the smaller the amount of phase change. In the first radio wave control board 14H-1, the amount of phase change changes concentrically.

[0064] 17B shows the phase distribution of the second radio wave control board 14H-2. The second radio wave control board 14H-2 has, for example, the same phase distribution as the first radio wave control board 14H-1. The second radio wave control board 14H-2 is placed inside the housing 12 rotated by a predetermined angle θ (θ = 30° in FIG. 17B) with respect to the phase distribution of the first radio wave control board 14H-1. As the relative angle of the phase distribution of the second radio wave control board 14H-2 with respect to the phase distribution of the first radio wave control board 14H-1 changes, the phase distribution of the superposition of the first radio wave control board 14H-1 and the second radio wave control board 14H-2 changes.

[0065] 18A and 18B are diagrams showing an example of a superimposed phase distribution according to the sixth embodiment. FIG. 18A shows a superimposed phase distribution 60 when the relative angle of the phase distribution of the second radio wave control plate 14H-2 with respect to the phase distribution of the first radio wave control plate 14H-1 is 15°. FIG. 18B shows a superimposed phase distribution 62 when the relative angle of the phase distribution of the second radio wave control plate 14H-2 with respect to the phase distribution of the first radio wave control plate 14H-1 is 30°. As shown by the phase distributions 60 and 62, the moiré pattern of the phase distribution changes as the relative angle of the phase distribution of the second radio wave control plate 14H-2 with respect to the phase distribution of the first radio wave control plate 14H-1 changes. This allows the focal length to be changed.

[0066] Next, a method for changing the focal position of the radio waves will be described. As explained in Figures 18A and 18B, the focal length of the radio waves changes by changing the relative angle of the phase distribution of second radio wave control plate 14H-2 with respect to the phase distribution of first radio wave control plate 14H-1. To change the focal position of the radio waves, first radio wave control plate 14H-1 and second radio wave control plate 14H-2 are rotated as a whole around a position different from the center of the overlapping phase distribution of first radio wave control plate 14H-1 and second radio wave control plate 14H-2.

[0067] Fig. 19 is a diagram for explaining a method for changing the focal position of radio waves according to the sixth embodiment. In the example shown in Fig. 19, first radio wave control plate 14H-1 and second radio wave control plate 14H-2 are disposed inside housing 12 that is circular when viewed from the Z-axis direction.

[0068] Phase center O1 indicates the center of the superimposed phase distribution 60 of first radio wave control plate 14H-1 and second radio wave control plate 14H-2. Rotation center O2 indicates the overall rotation center of first radio wave control plate 14H-1 and second radio wave control plate 14H-2 inside housing 12. By rotating first radio wave control plate 14H-1 and second radio wave control plate 14H-2 around rotation center O2 using a rotation mechanism (not shown), phase center O1 moves along arrow V20. In this way, by moving the position of phase center O1 inside housing 12C, the focal position of the radio waves can be changed.

[0069] As described above, in the sixth embodiment, the focal position of the radio waves can be changed by changing the relative angle of the phase distribution of the two radio wave control plates.

[0070] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the contents of these embodiments. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-described 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 above-described embodiments.

[0071] REFERENCE SIGNS LIST 1 wireless communication system 2 base station 3 terminal 4 radio wave control board 10, 10A, 10B radio wave control device 12, 12A, 12B, 12C housing 14, 14A, 14B, 14C, 14D, 14E, 14F, 14G radio wave control board 14H-1 first radio wave control board 14H-2 second radio wave control board 16, 16A, 16B rotation mechanism

Claims

1. A housing and a radio wave control plate that is installed in the housing and controls the direction of emission of an incident wave from a base station; a rotation mechanism that is installed in the housing and rotates the radio wave control plate within a first plane; A radio wave control device comprising:

2. When the distance between the radio wave control plate and a terminal or base station receiving the outgoing wave emitted from the radio wave control plate is d, the reflection angle or refraction angle of the incident wave at the radio wave control plate is θ, and the beam width of the outgoing wave is w, the relationship of the following formula (1) is satisfied: The radio wave control device according to claim 1 . d・tanθ≧w / 2・cosθ...(1)

3. The radio wave control plate includes: The radio wave control plate is installed so that an angle between a straight line connecting the radio wave control plate and the base station and a normal direction of the radio wave control plate is smaller than a refraction angle of the incident wave at the radio wave control plate. The radio wave control device according to claim 2.

4. The radio wave control plate has an outer shape of a constant width figure. The radio wave control device according to claim 2 or 3.

5. A plurality of the radio wave control plates each having a different phase distribution, the rotation mechanism rotates at least one of the plurality of radio wave control plates within the first plane to change a relative angle of a phase distribution of each of the plurality of radio wave control plates; The radio wave control device according to claim 1 .

6. controlling the direction of emission of an incident wave from a base station by a radio wave control plate installed in the housing; rotating the radio wave control plate within a first plane to control an emission direction; A radio wave control method comprising: