Radio wave refraction plate

Abstract

This radio wave refraction plate includes: a plurality of unit structures arranged in a first plane direction; and a plurality of radio wave refraction regions including a plurality of unit structures and having mutually different refraction angles in a first angle direction relative to radio waves.

Description

Radio wave refraction plate

[0001] The present disclosure relates to a wave refracting plate.

[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 refraction plate of the present disclosure includes a plurality of unit structures arranged in a first surface direction, and a plurality of radio wave refraction regions including the plurality of unit structures and having different refraction angles in a first angle direction for radio waves.

[0005] FIG. 1 is a diagram illustrating an example of the configuration of a radio wave refraction plate according to each embodiment. FIG. 2 is a diagram illustrating a method of using the radio wave refraction plate. FIG. 3 is a diagram illustrating an example of the configuration of a radio wave refraction plate according to the first embodiment. FIG. 4 is a diagram illustrating the beam width of a refracted wave according to the first embodiment. FIG. 5 is a diagram illustrating an example of the configuration of a radio wave refraction plate according to the second embodiment. FIG. 6 is a diagram illustrating a method of refracting radio waves using a radio wave refraction plate according to the third embodiment. FIG. 7 is a diagram illustrating the refraction angle of a radio wave refraction region according to the third embodiment. FIG. 8 is a diagram illustrating the gain characteristics of a refracted wave according to a comparative example of the fourth embodiment. FIG. 9 is a diagram illustrating an example of the configuration of a radio wave refraction plate according to the fourth embodiment. FIG. 10 is a diagram illustrating the gain characteristics of a refracted wave according to the fourth embodiment. FIG. 11 is a diagram illustrating the refraction angle in a first direction of a radio wave refraction plate according to the fifth embodiment. FIG. 12 is a diagram illustrating the gain characteristics of a refracted wave in a first direction of a radio wave refraction plate according to the fifth embodiment. FIG. 13 is a diagram illustrating the refraction angle in a second direction of a radio wave refraction plate according to the fifth embodiment. FIG. 14 is a diagram for explaining the refraction angle in the second direction of the radio wave refraction plate according to the fifth embodiment.

[0006] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the present disclosure is not limited to this embodiment, and in the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted.

[0007] 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. 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 including the X-axis and Y-axis will be referred to as the XY plane, the plane including the X-axis and Z-axis will be referred to as the XZ plane, and the plane including the Y-axis and Z-axis will be 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.

[0008] [Embodiments] (Radio wave refraction plate) A configuration example of a radio wave refraction plate according to each embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing a configuration example of a radio wave refraction plate according to each embodiment.

[0009] The radio wave refraction plate 1a is a plate-shaped member configured to allow radio waves transmitted from a base station to pass through. The radio wave refraction plate 1a is configured, for example, to receive radio waves transmitted from a base station, refract the radio waves at a predetermined angle, and then emit the radio waves. The radio wave refraction plate 1a can be configured, for example, with a metamaterial that changes the phase of the incident wave.

[0010] As shown in FIG. 1, the radio wave refraction plate 1a can include, for example, a substrate 2, a unit structure 10a, a unit structure 10b, a unit structure 10c, and a unit structure 10d.

[0011] The unit structures 10a, 10b, 10c, and 10d may be formed on a substrate 2. The substrate 2 may be, for example, a dielectric substrate made of a dielectric material. The substrate 2 may have, for example, but is not limited to, a rectangular shape. The unit structures 10a, 10b, 10c, and 10d may be arranged two-dimensionally on the substrate 2. The arrangement method of the unit structures 10a, 10b, 10c, and 10d is also called a phase distribution.

[0012] Specifically, in the substrate 2, a plurality of unit structures 10a may be installed, for example, on the bottom row of the substrate 2. In the substrate 2, a plurality of unit structures 10b may be installed in a row on the row above the row on which the unit structures 10a are installed. In the substrate 2, a plurality of unit structures 10c may be installed in a row on the row above the row on which the unit structures 10b are installed. In the substrate 2, a plurality of unit structures 10d may be installed in a row on the row above the row on which the unit structures 10c are installed. In other words, the radio wave refraction plate 1 may have a structure in which a plurality of unit structures of different sizes are periodically arranged. The unit structures 10a to 10d may each vary in the frequency band and the amount of phase change of the radio waves they change. Although the unit structures 10a to 10d each have a rectangular shape, this is not limiting. By changing the sizes and shapes of the unit structures 10a, 10b, 10c, and 10d, the frequency band and the amount of phase change of the radio waves to be refracted can be adjusted.

[0013] 2 is a diagram illustrating a method of using a radio wave refraction plate. As shown in Fig. 2, the radio wave refraction plate 1a is configured to refract a radio wave W1 transmitted from a base station 3 at a predetermined angle and emit a refracted wave W2 to a receiving device 4. In the present disclosure, the angle between the Z axis and a line projected onto the XZ plane of the refracted wave W2 is defined as θ, and the angle between the Y axis and a line projected onto the XY plane of the refracted wave W2 is defined as φ.

[0014] The phase distribution of the radio wave refraction plate 1a is set according to the desired angles θ and φ. Usually, the phase distribution of the radio wave refraction plate 1a is determined based on the following formula (1).

[0015]

[0016] In formula (1), ΔΦ is the phase difference between adjacent unit structures, k is the wave number of the radio wave, dx is the distance between adjacent unit structures in the X direction, and dy is the distance between adjacent unit structures in the Y direction.

[0017] However, the refracted wave W2 emitted by the radio wave refraction plate 1a designed based on Equation (1) has a problem in that the beam width is narrow in the far-field region. In this case, if a receiving device 4 is installed in the far-field region, the receiving device 4 may not be able to properly receive the refracted wave W2. Therefore, the present disclosure provides a radio wave refraction plate that can widen the beam width of the refracted wave W2 even in the far-field region.

[0018] [First embodiment] A configuration example of a radio wave refraction plate according to the first embodiment will be described with reference to Fig. 3. Fig. 3 is a diagram showing a configuration example of a radio wave refraction plate according to the first embodiment.

[0019] 3, the radio wave refraction plate 1 includes a first radio wave refraction region 11 and a second radio wave refraction region 12. The radio wave refraction plate 1 is configured to receive radio waves W1 transmitted from the base station 3 and emit them toward the vicinity of point C in the XZ plane (refractive surface). The radio wave refraction plate 1 is divided in the Y-axis direction (horizontal direction) in the XY plane.

[0020] The first radio wave refraction region 11 and the second radio wave refraction region 12 are regions obtained by dividing the radio wave refraction plate 1 perpendicularly to the refraction surface. The first radio wave refraction region 11 is configured to refract the received radio wave W1 and emit a refracted wave W2-1 toward the vicinity of point C. The second radio wave refraction region 12 is configured to refract the received radio wave W1 and emit a refracted wave W2-2 toward the vicinity of point C.

[0021] The first radio wave refraction region 11 and the second radio wave refraction region 12 are configured to have different refraction angles of the radio wave W1. The first radio wave refraction region 11 and the second radio wave refraction region 12 are configured to have different phase distributions, for example, to have different refraction angles of the radio wave W1. That is, the refraction angles of the radio wave W1 can be set independently for the first radio wave refraction region 11 and the second radio wave refraction region 12. In the first embodiment, by setting the refraction angle of the radio wave W1 for each radio wave refraction region, the beam width in the θ direction of the refracted wave toward point C can be widened.

[0022] FIG. 4 is a diagram illustrating the beam width of a refracted wave according to the first embodiment. As shown in FIG. 4, the first radio wave refraction region 11 refracts the radio wave W1 and emits a refracted wave W2-1 toward the vicinity of point C. Region R11 indicates the beam width of the refracted wave W2-1 on a hemispherical surface including point C. The second radio wave refraction region 12 refracts the radio wave W1 and emits a refracted wave W2-2 toward the vicinity of point C. Region R12 indicates the beam width of the refracted wave W2-2 on a hemispherical surface including point C. Region R1 indicates the beam width of the refracted wave obtained by refracting the radio wave W1 by the radio wave refraction plate 1 on a hemispherical surface including point C. Region R1 is a combined region of regions R11 and R12. Region R11 and region R12 are aligned in the θ direction. That is, in the first embodiment, by dividing the radio wave refraction plate 1 into a plurality of radio wave refraction regions, such as the first radio wave refraction region 11 and the second radio wave refraction region 12, the beam width in the θ direction on the hemispherical surface including point C can be widened.

[0023] The first radio wave refraction region 11 and the second radio wave refraction region 12 may be the same size or different sizes. The first radio wave refraction region 11 and the second radio wave refraction region 12 may be formed, for example, by forming two regions with different phase distributions in a single radio wave refraction plate 1. The first radio wave refraction region 11 and the second radio wave refraction region 12 may be formed, for example, by arranging two radio wave refraction plates with different phase distributions side by side. When the first radio wave refraction region 11 and the second radio wave refraction region 12 are formed using two radio wave refraction plates, the two radio wave refraction plates may be arranged so as to be in contact with each other or with a predetermined gap between them.

[0024] In the first embodiment, the radio wave refraction plate 1 has been described as including two radio wave refraction regions, the first radio wave refraction region 11 and the second radio wave refraction region 12. However, the present disclosure is not limited to this. The radio wave refraction plate 1 may include three or more radio wave refraction regions.

[0025] As described above, in the first embodiment, the radio wave refraction plate 1 includes a plurality of radio wave refraction regions that are perpendicular to the refraction surface and have different refraction angles for the radio waves W1, thereby enabling the first embodiment to widen the beam width in the far-field region of the refracted waves refracted by the radio wave refraction plate 1.

[0026] Second Embodiment A configuration example of a radio wave refraction plate according to a second embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram showing a configuration example of a radio wave refraction plate according to the second embodiment.

[0027] 5, the radio wave refraction plate 1A includes a first radio wave refraction region 11A, a second radio wave refraction region 12A, a third radio wave refraction region 13A, and a fourth radio wave refraction region 14A. The radio wave refraction plate 1A is divided in both the X-axis direction (vertical direction) and the Y-axis direction (horizontal direction) in the XY plane.

[0028] The first radio wave refraction region 11A is configured to refract the radio wave W1 and emit a refracted wave W2A-1 toward the vicinity of point C. The second radio wave refraction region 12A is configured to refract the radio wave W1 and emit a refracted wave W2A-2 toward the vicinity of point C. The third radio wave refraction region 13A is configured to refract the radio wave W1 and emit a refracted wave W2A-3 toward the vicinity of point C. The fourth radio wave refraction region 14A is configured to refract the radio wave W1 and emit a refracted wave W2A-4 toward the vicinity of point C.

[0029] The first to fourth radio wave refraction regions 11A to 14A are configured to have different refraction angles of the radio wave W1. The first to fourth radio wave refraction regions 11A to 14A are configured to have different phase distributions, for example, to have different refraction angles of the radio wave W1. That is, the refraction angles of the radio wave W1 can be set independently for the first to fourth radio wave refraction regions 11A to 14A. In the second embodiment, by setting the refraction angle of the radio wave W1 for each radio wave refraction region, the beam widths of the refracted waves in the θ and φ directions on the hemisphere including point C can be widened.

[0030] Region R11A shows the beam width on the hemisphere including point C of refracted wave W2A-1. Region R12A shows the beam width on the hemisphere including point C of refracted wave W2A-2. Region R13A shows the beam width on the hemisphere including point C of refracted wave W2A-3. Region R14A shows the beam width on the hemisphere including point C of refracted wave W2A-4. Region R1A is a combined region of regions R11A, R12A, R13A, and R14A. Regions R11A and R12A are aligned in the θ direction. Regions R13A and R14A are aligned in the θ direction. Regions R11A and R13A are aligned in the φ direction. Regions R12A and R14A are aligned in the φ direction. The regions R11A and R12A, and the regions R13A and R14A are aligned in a direction perpendicular to the refraction surface. The regions R11A and R13A, and the regions R12A and R14A are aligned in a direction parallel to the refraction surface. That is, in the second embodiment, by dividing the radio wave refraction plate 1A into a plurality of radio wave refraction regions, such as the first radio wave refraction region 11A to the fourth radio wave refraction region 14A, it is possible to widen the beam widths in the θ direction and the φ direction on the hemispherical surface including the point C.

[0031] The first radio wave refraction region 11A to the fourth radio wave refraction region 14A may each be the same size or different sizes. The first radio wave refraction region 11A to the fourth radio wave refraction region 14A may each be formed, for example, by forming four regions with different phase distributions in a single radio wave refraction plate 1A. The first radio wave refraction region 11A to the fourth radio wave refraction region 14A may each be formed, for example, by arranging four radio wave refraction plates with different phase distributions. When the first radio wave refraction region 11A to the fourth radio wave refraction region 14A are formed using four radio wave refraction plates, the four radio wave refraction plates may be arranged so as to be in contact with each other or at a predetermined interval.

[0032] In the second embodiment, the radio wave refraction plate 1A has been described as including four radio wave refraction regions, namely, the first radio wave refraction region 11A to the fourth radio wave refraction region 14A, but the present disclosure is not limited thereto. The radio wave refraction plate 1A may include five or more radio wave refraction regions.

[0033] As described above, in the second embodiment, the radio wave refraction plate 1A includes a plurality of radio wave refraction regions that are perpendicular and parallel to the refraction surface and have different refraction angles for the radio waves W1. This makes it possible to more appropriately widen the beam width in the far-field region of the refracted waves refracted by the radio wave refraction plate 1A in the second embodiment.

[0034] 6 is a diagram illustrating a method of refracting radio waves using a radio wave refraction plate according to a third embodiment. For example, if point C, which is the center of the region where the refracted waves are desired to be spread, is included within the beam widths in the θ and φ directions of the refracted waves from each of the first to fourth radio wave refraction regions 11A to 14A, the received power at the position of point C may be larger than necessary, which may result in a narrower beam width of the refracted waves in the direction of point C.

[0035] In the third embodiment, the refraction angle is set so that point C is not included within the beam width in both the θ direction and the φ direction of the refracted wave from at least one of the multiple radio wave refraction regions. Also, in the third embodiment, the refraction angle of the radio wave refraction region that emits the refracted wave that is set so that point C is not included is set so that it overlaps within the half-width with the refracted wave from the radio wave refraction region that is set so that point C is included in both the θ direction and the φ direction.

[0036] Fig. 7 is a diagram for explaining the refraction angle of a radio wave refraction region according to the third embodiment. In Fig. 7, the horizontal axis represents the refraction angle [deg (degrees)] in the θ direction, and the vertical axis represents the gain [dB (decibels)]. A line 101 indicates the position of point C. A beam pattern 102 shows the gain characteristics of a refracted wave from a radio wave refraction region in which the refraction angle is set so that point C is not included within the beam width. A beam pattern 103 shows the gain characteristics of a refracted wave from a radio wave refraction region in which point C is set so that point C is included within the beam width.

[0037] Half-width 104 indicates the half-width of the refracted wave from the radio wave refraction region where the refraction angle is set so that point C is not included within the beam width. Half-width 105 indicates the half-width of the refracted wave from the radio wave refraction region where the refraction angle is set so that point C is included within the beam width. As shown in FIG. 7 , point C is located outside half-width 104 and within half-width 105. Furthermore, as shown by beam pattern 102 and beam pattern 103, the refracted wave from the radio wave refraction region where the refraction angle is set so that point C is not included within the beam width overlaps within half-width 104 and half-width 105.

[0038] In this way, the third embodiment can prevent the received power at the position of point C from becoming larger than necessary. As a result, the third embodiment can prevent the beam width at the position on the hemisphere including point C from becoming narrow.

[0039] [Fourth Embodiment] A fourth embodiment will be described. When attempting to widen the beam width in the far-field region by adjusting only the refraction angle of the radio wave refraction region, it may be impossible to obtain a flat beam pattern. FIG. 8 is a diagram showing the gain characteristics of a refracted wave according to a comparative example of the fourth embodiment. In FIG. 8, the horizontal axis represents the refraction angle [deg], and the vertical axis represents the gain [dB]. A beam pattern 110 represents the gain characteristics of a refracted wave emitted by the entire radio wave refraction plate 1 (see FIG. 4). A beam pattern 111 represents the gain characteristics of a refracted wave W2-1 emitted by the first radio wave refraction region 11 (see FIG. 4). A beam pattern 112 represents the gain characteristics of a refracted wave W2-2 emitted by the second radio wave refraction region 12 (see FIG. 4). The beam pattern 110 is a superposition of the beam pattern 111 and the beam pattern 112.

[0040] As shown in beam pattern 110, the refracted wave does not form a flat beam pattern in range 113, which is an angular region where the beam width of the refracted wave is desired to be widened. This is because beam pattern 111 has null point P1 and beam pattern 112 has null point P2. Null point P1 and null point P2 are located within range 113. Therefore, when beam pattern 111 and beam pattern 112 are superimposed, ripples occur in beam pattern 110 in range 113, and a flat beam pattern cannot be obtained in range 113. Therefore, in the fourth embodiment, a refracted wave having a flat beam pattern is formed by appropriately setting the aperture size of each radio wave refraction region.

[0041] Here, if the wavelength of the refracted wave is λ, the aperture size of each radio wave refraction region is d, the angle of the first null on the high frequency side is α, and the angle of the first null on the low frequency side is β, the following equation (2) holds.

[0042]

[0043] The range in which a flat beam pattern is desired to be formed is defined as Δθ. In this case, the beam pattern should be formed between the first null on the high frequency side and the first null on the low frequency side, and the following equation (3) holds.

[0044]

[0045] When formula (3) is satisfied, the null point of the refracted wave emitted from each radio wave refraction region will not fall within the angle region where you want to create a flat beam pattern. In other words, by setting the aperture size of each radio wave refraction region to satisfy formula (4) below, you can create a flat beam pattern in the desired range.

[0046]

[0047] In the example shown in FIG. 8, equation (4) is not satisfied, and therefore a flat beam pattern is not obtained in the range 113.

[0048] An example of the configuration of a radio wave refraction plate according to the fourth embodiment will be described with reference to Fig. 9 . Fig. 9 is a diagram showing an example of the configuration of a radio wave refraction plate according to the fourth embodiment. As shown in Fig. 9 , the radio wave refraction plate 1B has a first radio wave refraction region 11B, a second radio wave refraction region 12B, a third radio wave refraction region 13B, and a fourth radio wave refraction region 14B. The radio wave refraction plate 1B is divided in the Y-axis direction (horizontal direction) on the XY plane. The sizes of the openings of the first radio wave refraction region 11B to the fourth radio wave refraction region 14B are each determined to satisfy formula (4).

[0049] The first radio wave refraction region 11B is configured to refract the radio wave W1 and emit a refracted wave W2B-1. The first radio wave refraction region 11B is configured to refract the radio wave W1 by 42.5° in the θ direction, for example.

[0050] The second radio wave refraction region 12B is configured to refract the radio wave W1 and emit a refracted wave W2B-2. The second radio wave refraction region 12B is configured to refract the radio wave W1 by 44° in the θ direction, for example.

[0051] The third radio wave refraction region 13B is configured to refract the radio wave W1 and emit a refracted wave W2B-3. The third radio wave refraction region 13B is configured to refract the radio wave W1 by 46° in the θ direction, for example.

[0052] The fourth radio wave refraction region 14B is configured to refract the radio wave W1 and emit a refracted wave W2B-4. The fourth radio wave refraction region 14B is configured to refract the radio wave W1 by 50° in the θ direction, for example.

[0053] That is, among the first radio wave refraction region 11B to the fourth radio wave refraction region 14B, the refraction angle of the radio wave W1 in the first radio wave refraction region 11B is configured to be the gentlest, and the refraction angle of the radio wave W1 in the fourth radio wave refraction region 14B is configured to be the steepest.

[0054] FIG. 10 is a diagram showing the gain characteristics of refracted waves according to the fourth embodiment. In FIG. 10, the horizontal axis represents the refraction angle [deg], and the vertical axis represents the gain [dB]. Beam pattern 120 represents the gain characteristics of the refracted wave emitted by the entire radio wave refraction plate 1B. Beam pattern 121 represents the gain characteristics of the refracted wave W2B-1 emitted by the first radio wave refraction region 11B. Beam pattern 122 represents the gain characteristics of the refracted wave 2B-2 emitted by the second radio wave refraction region 12B. Beam pattern 123 represents the gain characteristics of the refracted wave W2B-3 emitted by the third radio wave refraction region 13B. Beam pattern 124 represents the gain characteristics of the refracted wave W2B-4 emitted by the fourth radio wave refraction region 14B. Beam pattern 120 is a superposition of beam pattern 121, beam pattern 122, beam pattern 123, and beam pattern 124. Beam pattern 121 has a null point P11. Beam pattern 122 has a null point P12. Beam pattern 123 has a null point P13. Beam pattern 124 has a null point P14.

[0055] In the fourth embodiment, as shown by beam pattern 120, in range 125, which is an angular region in which the beam width of the refracted wave is desired to be widened, the refracted wave forms a flat beam pattern with fewer ripples than the beam pattern 110 shown in Fig. 8. This is because null point P11, null point P12, null point P13, and null point P14 are located outside range 125. Therefore, in the fourth embodiment, when beam pattern 121, beam pattern 122, beam pattern 123, and beam pattern 124 are superimposed, it is possible to prevent the occurrence of ripples in range 125 of beam pattern 120.

[0056] Furthermore, as shown in beam pattern 120, a range 125 which is a flat beam pattern is formed between the first null (null point P14) on the low frequency side of beam pattern 124 and the first null (null point P15) on the high frequency side of beam pattern 121.

[0057] Here, the angles of the peak point P21 and the null point P15 of the beam pattern 121 are respectively defined as θ ａ and θ ａ１ＨThe angles of the peak point P22 and the null point P14 of the beam pattern 124 are respectively set as θ ｄ and θ ｄ１Ｌ If the range 125 is Δθ, Δθ is expressed by the following equation (5).

[0058]

[0059] In general, when the peak angle is γ, the angle of the first null is β, the wavelength of the refracted wave is λ, and the size of the opening is d, the following equation (6) holds.

[0060]

[0061] Since Equation (6) holds, if the central angle at which you want to spread the refracted wave is θ, then when the range in which you want to flatten the refracted wave is determined, θ ａ and θ ｄ A desired beam pattern can be obtained by determining based on the following equation (7).

[0062]

[0063] Specifically, in the fourth embodiment, the size d of each opening can be calculated based on equations (2) to (4). Then, by substituting the calculated size d of each opening into equation (7), θ ａ and θ ｄ can be calculated.

[0064] As described above, the fourth embodiment can calculate the size of the aperture based on the angle of the null point of the refracted wave emitted from each radio wave refraction region. The fourth embodiment can then calculate the angle of the peak point of the refracted wave emitted from each radio wave refraction region based on the calculated size of the aperture. This allows the fourth embodiment to form a more appropriately flat beam pattern within a desired range.

[0065] [Fifth Embodiment] The fifth embodiment will be described with reference to Fig. 11 to Fig. 14. Fig. 11 is a diagram for explaining the refraction angle in the first direction of the radio wave refraction plate according to the fifth embodiment. Fig. 12 is a diagram showing the gain characteristics of the refracted wave in the first direction of the radio wave refraction plate according to the fifth embodiment. Fig. 13 is a diagram for explaining the refraction angle in the second direction of the radio wave refraction plate according to the fifth embodiment. Fig. 14 is a diagram for explaining the refraction angle in the second direction of the radio wave refraction plate according to the fifth embodiment.

[0066] 11, the radio wave refraction plate 1C includes a first radio wave refraction region 11C-1, a first radio wave refraction region 11C-2, a first radio wave refraction region 11C-3, a first radio wave refraction region 11C-4, a second radio wave refraction region 12C-1, a second radio wave refraction region 12C-2, a second radio wave refraction region 12C-3, a second radio wave refraction region 12C-4, a third radio wave refraction region 13C-1, a third radio wave refraction region 13C-2, a third radio wave refraction region 13C-3, a third radio wave refraction region 13C-4, a fourth radio wave refraction region 14C-1, a fourth radio wave refraction region 14C-2, a fourth radio wave refraction region 14C-3, and a fourth radio wave refraction region 14C-4. That is, the radio wave refraction plate 1C includes 16 radio wave refraction regions. The radio wave refraction plate 1C is configured to refract the radio wave W1 using 16 radio wave refraction regions and emit refracted waves W2. The radio wave refraction plate 1C is divided in both the X-axis direction (vertical direction) and the Y-axis direction (horizontal direction) in the XY plane.

[0067] The first radio wave refraction region 11C-1, the first radio wave refraction region 11C-2, the first radio wave refraction region 11C-3, and the first radio wave refraction region 11C-4 may be collectively referred to as a first radio wave refraction region group. The second radio wave refraction region 12C-1, the second radio wave refraction region 12C-2, the second radio wave refraction region 12C-3, and the second radio wave refraction region 12C-4 may be collectively referred to as a second radio wave refraction region group. The third radio wave refraction region 13C-1, the third radio wave refraction region 13C-2, the third radio wave refraction region 13C-3, and the third radio wave refraction region 13C-4 may be collectively referred to as a third radio wave refraction region group. The fourth radio wave refraction region 14C-1, the fourth radio wave refraction region 14C-2, the fourth radio wave refraction region 14C-3, and the fourth radio wave refraction region 14C-4 may be collectively referred to as a fourth radio wave refraction region group.

[0068] In Figure 12, the horizontal axis represents the refraction angle [deg] in the θ direction, and the vertical axis represents the gain [dB]. Beam pattern 130 represents the gain characteristics of refracted waves in the θ direction emitted by the entire radio wave refraction plate 1C. Beam pattern 131 represents the gain characteristics of refracted waves emitted by the first group of radio wave refraction regions. Beam pattern 132 represents the gain characteristics of refracted waves emitted by the second group of radio wave refraction regions. Beam pattern 133 represents the gain characteristics of refracted waves emitted by the third group of radio wave refraction regions. Beam pattern 134 represents the gain characteristics of refracted waves emitted by the fourth group of radio wave refraction regions. Beam pattern 130 is a superposition of beam pattern 131, beam pattern 132, beam pattern 133, and beam pattern 134. In the fifth embodiment, as shown by beam pattern 130, the radio wave refraction plate 1C can emit a refracted wave with a flat beam pattern in a range 135 between the peak angle of beam pattern 131 and the peak angle of beam pattern 134.

[0069] 13 is a diagram illustrating the refraction angle in the second direction of the radio wave refraction plate according to the fifth embodiment. The first radio wave refraction region 11C-4, the second radio wave refraction region 12C-4, the third radio wave refraction region 13C-4, and the fourth radio wave refraction region 14C-4 may be collectively referred to as a fifth radio wave refraction region group. The first radio wave refraction region 11C-3, the second radio wave refraction region 12C-3, the third radio wave refraction region 13C-3, and the fourth radio wave refraction region 14C-3 may be collectively referred to as a sixth radio wave refraction region group. The first radio wave refraction region 11C-2, the second radio wave refraction region 12C-2, the third radio wave refraction region 13C-2, and the fourth radio wave refraction region 14C-2 may be collectively referred to as a seventh radio wave refraction region group. The first radio wave refraction region 11C-1, the second radio wave refraction region 12C-1, the third radio wave refraction region 13C-1, and the fourth radio wave refraction region 14C-1 may be collectively referred to as an eighth radio wave refraction region group.

[0070] In Figure 14, the horizontal axis represents the refraction angle [deg] in the φ direction, and the vertical axis represents the gain [dB]. Beam pattern 140 represents the gain characteristics of refracted waves in the φ direction emitted by the entire radio wave refraction plate 1C. Beam pattern 141 represents the gain characteristics of refracted waves emitted by the fifth radio wave refraction region group. Beam pattern 142 represents the gain characteristics of refracted waves emitted by the sixth radio wave refraction region group. Beam pattern 143 represents the gain characteristics of refracted waves emitted by the seventh radio wave refraction region group. Beam pattern 144 represents the gain characteristics of refracted waves emitted by the eighth radio wave refraction region group. Beam pattern 140 is a superposition of beam pattern 141, beam pattern 142, beam pattern 143, and beam pattern 144. In the fifth embodiment, as shown by the beam pattern 140, the radio wave refraction plate 1C can emit a refracted wave with a flat beam pattern in a range 145 between the peak angle of the beam pattern 141 and the peak angle of the beam pattern 144.

[0071] In the fifth embodiment, the size d of each opening is calculated based on equations (2) to (4), and the calculated size d of each opening is substituted into equation (7), thereby obtaining θ ａ and θ ｄ The formulas (5) to (7) are the same in the φ direction, so the explanation will be omitted.

[0072] As described above, the fifth embodiment can calculate the size of the aperture based on the angle of the null point of the refracted wave emitted from each radio wave refraction region. The fifth embodiment can then calculate the angle of the peak point of the refracted wave emitted from each radio wave refraction region based on the calculated size of the aperture. This allows the fifth embodiment to form a more appropriately flat beam pattern within a desired range.

[0073] 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.

[0074] 1, 1a, 1A, 1B Radio wave refraction plate 3 Base station 4 Receiving device 10a, 10b, 10c, 10d Unit structure 11, 11A, 11B First radio wave refraction region 12, 12A, 12B Second radio wave refraction region 13B Third radio wave refraction region 14B Fourth radio wave refraction region

Claims

1. a plurality of unit structures arranged in a first surface direction; a plurality of radio wave refraction regions each including a plurality of the unit structures and each having a different refraction angle in a first angular direction with respect to the radio wave; A radio wave refraction plate including:

2. The plurality of radio wave refraction regions are regions divided in both the vertical and horizontal directions.

2. The radio wave refraction plate according to claim 1.

3. The plurality of radio wave refraction regions are formed so that refraction angles in the first angular direction and a second angular direction different from the first angular direction with respect to the radio wave are different from each other.

3. The radio wave refraction plate according to claim 1 or 2.