Electromagnetic wave control plate

Abstract

Provided is an electromagnetic wave control plate capable of emitting a beam in a predetermined direction θ0 on the basis of an incoming electromagnetic wave, the electromagnetic wave control plate comprising a plurality of unit structures arranged so as to impart a gradient of phase change amount along a first direction. A phase change amount Ψn of the n-th (n is an integer) unit structure in the first direction is set in a region between a first line represented by formula (1) and a second line represented by formula (2) in a two-dimensional coordinate system in which the horizontal axis represents the positions of the unit structures in the first direction and the vertical axis represents the phase change amount.　(1) KynsinθA, (2) kynsinθB, where k is the wavenumber of the electromagnetic wave.　yn is the coordinate of the unit structure in the first direction.　θA < θ0 < θB.

Description

Radio Control Board

[0001] The present disclosure relates to a radio wave control board.

[0002] A radio wave scattering device is known that includes a plurality of radio wave scattering units that scatter radio waves. For example, Patent Document 1 discloses a technique that can widen the scattered beam width compared to a case where the phases of the plurality of radio wave scattering units are not corrected.

[0003] Japanese Patent Application Laid-Open No. 2022-189533

[0004] The radio wave control plate of the present disclosure is configured to control the radio wave in a predetermined direction θ based on the incident radio wave. ０ a radio wave control plate capable of emitting a beam in a direction perpendicular to the plane of the optical axis, the radio wave control plate including a plurality of unit structures arranged so as to have a gradient of a phase change amount along a first direction, the phase change amount Ψ of an n-th unit structure (n is an integer) in the first direction being ｎ is set in the region between the first line expressed by formula (1) and the second line expressed by formula (2) in a two-dimensional coordinate system in which the horizontal axis represents the position of the unit feature in the first direction and the vertical axis represents the amount of phase change. ｎ sinθ Ａ ... (1) ky ｎ sinθ Ｂ ...(2) k is the wave number of the radio wave, and y ｎ is the coordinate of the unit feature in the first direction, and θ Ａ <θ ０ <θ Ｂ is.

[0005] FIG. 1 is a diagram for explaining a radio wave control plate according to a first embodiment. FIG. 2 is a diagram for explaining a phase distribution of the radio wave control plate according to the first embodiment. FIG. 3 is a diagram for explaining the angle dependency of beam intensity according to the first embodiment. FIG. 4 is a diagram for explaining the θ ｎand the beam width. Fig. 5 is a diagram for explaining the amount of phase change of a unit feature according to the third embodiment. Fig. 6 is a diagram for explaining the relationship between the amount of phase change and the shape of the beam according to the third embodiment. Fig. 7 is a diagram for explaining the phase distribution of a radio wave control plate according to the fourth embodiment. Fig. 8 is a diagram for explaining the shape of a beam focused by a radio wave control plate according to the fourth embodiment. Fig. 9 is a diagram for explaining the relationship between the focal length and the shape of the beam according to the fourth embodiment.

[0006] 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.

[0007] [First embodiment] (Radio wave control plate) A radio wave control plate according to a first embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram for explaining the radio wave control plate according to the first embodiment.

[0008] The radio wave control plate is a component configured to be able to reflect or refract incident radio waves at a predetermined angle. For example, when the radio wave control plate receives radio waves transmitted from a base station, it reflects or refracts the radio waves at a predetermined angle. The radio wave control plate has a plurality of unit structures, each having a change amount (phase change amount) relative to the phase of the incident radio waves, arranged two-dimensionally. The unit structures are made of, for example, metamaterial.

[0009] As shown in FIG. 1, the radio wave control plate 1 is made up of a plurality of unit structures 10 Ｎ (N is any natural number) to unit structure 10 -Ｎ Unit structure 10 Ｎ From unit structure 10 －Ｎ can be formed on the substrate 2. Ｎ From unit structure 10 －Ｎ can be arranged in two dimensions.

[0010] For example, unit structure 10 ０ are arranged along a straight line that passes through the origin and is parallel to the X-axis direction. ０ On the +Y axis direction side of １From unit structure 10 Ｎ are arranged along a straight line parallel to the X-axis direction. ０ On the −Y axis direction side of －１ From unit structure 10 －Ｎ are arranged along a straight line parallel to the X-axis direction. －Ｎ From unit structure 10 Ｎ are arranged along a straight line parallel to the Y-axis direction. －Ｎ From unit structure 10 Ｎ 1, the Y-axis direction is the gradient direction of the phase change amount (also referred to as the direction of the phase gradient).

[0011] Unit structure 10 ｎ (n is -N, -N+1...0...N-1, N) is called the nth unit structure, and n is called the element number. ｎ The amount of phase change relative to the incident radio wave is Ψ ｎ Then, Ψ ｎ can be expressed by the following equation (1).

[0012]

[0013] In equation (1), k is the wave number. If the wavelength of the incident radio wave is λ, k can be expressed as k = 2π / λ. ｎ is the unit structure 10 ｎ represents the position in the Y-axis direction. ｎ is the unit structure 10 adjacent in the Y-axis direction. ｎ If the interval between them is p, then y ｎ = np.

[0014] In the radio wave control board of the comparative example, θ ｎ is a predetermined fixed value θ ０ In this case, each unit structure 10 ｎ The phase change amount of Ψ ｎ =ky ｎ sinθ ０ , and is designed according to the formula: θ ０is the central angle of the beam emitted by the radio wave control plate.

[0015] On the other hand, in the radio wave control board 1 of the present disclosure, θ ｎ , [θ ０ -Δθ, θ ０ +Δθ] for each element number (i.e., for each unit structure). ０ is the central angle of the beam emitted by the radio wave control plate 1. The beam width of the beam emitted by the radio wave control plate 1 is 2Δθ. Note that the beam width is, for example, 3 dB, but is not limited to this value, and the value of Δθ can be changed depending on the design. θ ｎ [θ ０ -Δθ, θ ０ +Δθ], for example, according to uniform random numbers. ｎ The method of varying θ is not limited to uniform random numbers, but may be random numbers according to a normal distribution, for example. ０ -Δθ is the first angle θ Ａ It is called θ ０ +Δθ is the second angle θ Ｂ It is also sometimes called.

[0016] Ψ ｎ is a continuous real number in the range of [0, 2π]. However, it may be difficult to design the phase change amount of each unit structure 10 to be a continuous real number. Therefore, in this embodiment, for example, the set of design values ​​of the phase change amount is defined as {φ １ , φ ２ , φ ３ ,...φ ｌ} (where l is an arbitrary integer), the value may be a predetermined discrete value. In this case, Ψ ｎ , {φ １ , φ ２ , φ ３ ,...φ ｌ} may be replaced with the closest value.

[0017] [Phase Distribution] The distribution of the phase change amount (also simply referred to as phase distribution) of the radio wave control plate according to the first embodiment will be described with reference to Fig. 2. Fig. 2 is a diagram for explaining the phase distribution of the radio wave control plate according to the first embodiment.

[0018] 2, the horizontal axis represents the element number of the unit structure 10, and the vertical axis represents the phase change amount [deg]. In the example shown in FIG. 2, N=40, θ ｎ [θ ０ -Δθ, θ ０ +Δθ], θ ０ = 30 [deg], Δθ = 5 [deg]. ｎ The line 102 represents the phase gradient when θ = 25 [deg] in equation (1). ｎ = 35 degrees. Point 103 represents the result of setting the phase of each unit structure 10 according to uniform random numbers in the range of [25 degrees, 35 degrees]. Point 103 is set in the region between line 101 and line 102.

[0019] [Beam Intensity] The angle dependency of the beam intensity according to the first embodiment will be described with reference to Fig. 3. Fig. 3 is a diagram for explaining the angle dependency of the beam intensity according to the first embodiment.

[0020] 3, the horizontal axis represents the refraction direction [deg] of the emitted beam, and the horizontal axis represents the beam intensity [dB]. In the example shown in FIG. 3, the frequency is 28 [GHz], θ ０ = 30 [deg]. In the example shown in Fig. 3, the beam intensity is normalized so that the peak top value is 0 [dB].

[0021] FIG. 3(a) shows the beam shape when Δθ = 0 [deg]. FIG. 3(b) shows the beam shape when Δθ = 5 [deg]. FIG. 3(c) shows the beam shape when Δθ = 10 [deg]. As shown in FIG. 3(a), when Δθ = 0 [deg], the beam has a sharp peak in the 30° direction and the beam width is narrow. As shown in FIG. 3(b), when Δθ = 5 [deg], the beam width is wider than in FIG. 3(a). As shown in FIG. 3(c), when Δθ = 10 [deg], the beam width is wider than in FIGS. 3(a) and 3(b).

[0022] 3( a) to 3(c), the beam width increases as Δθ increases. That is, in the first embodiment, by controlling Δθ to vary the amount of phase change of each unit structure 10 included in radio wave control plate 1, the beam width of the beam emitted from radio wave control plate 1 can be appropriately controlled.

[0023] Second Embodiment Next, a second embodiment of the present disclosure will be described.

[0024] The beam emission direction is θ ０ The phase gradient in the -Δθ direction and the beam emission direction are θ ０ The standard deviation σ [θ ｎ ] and the beam width preferably satisfy a predetermined relationship.

[0025] where θ ｎ The method for deriving the standard deviation of [θ ０ -Δθ, θ ０ +Δθ], ｎ The average value of Ave [θ ｎ ]. Ave[θ ｎ ] can be expressed by the following formula (2).

[0026]

[0027] [θ ０ -Δθ, θ ０ +Δθ], ｎ The variance of σ ２ [θ ｎ ]. σ ２ [θ ｎ ] can be expressed by the following formula (3).

[0028]

[0029] [θ ０ -Δθ, θ ０ +Δθ], ｎ The standard deviation of σ [θ ｎ ], then σ[θ ｎ ] can be expressed by the following formula (4).

[0030]

[0031] Specifically, θ in a uniform probability distribution in the range of [0, 2π] ｎ The average value Ave [θ ｎ ] can be expressed by the following formula (5).

[0032]

[0033] θ in a uniform probability distribution in the range [0, 2π] ｎ Variance σ ２ [θ ｎ ] can be expressed by the following formula (6).

[0034]

[0035] θ in a uniform probability distribution in the range [0, 2π] ｎ Standard deviation σ [θ ｎ ] can be expressed by the following formula (7).

[0036]

[0037] The beam width BW is determined by the angle θ ０ The phase change amount indicated by the phase gradient in the -Δθ direction and the beam emission direction are ０ In a region where the difference with respect to the phase change amount indicated by the phase gradient in the +Δθ direction is 360° or less, it is preferable to satisfy the relationship of the following formula (8) using formula (4).

[0038]

[0039] The beam emission direction is θ ０ The phase change amount indicated by the phase gradient in the -Δθ direction and the beam emission direction are ０ In a region where the phase difference with respect to the phase change amount indicated by the phase gradient in the +Δθ direction exceeds 360°, the standard deviation σ[θ ｎ ] is preferably about π / √3.

[0040] 4, the θ ｎ The relationship between the standard deviation of θ and the beam width will be described. ｎ FIG. 10 is a diagram showing the relationship between the standard deviation of the beam width and the beam width.

[0041] In FIG. 4, the horizontal axis is θ ｎ Standard deviation σ [θ ｎ ] (deg), and the vertical axis represents the beam width (deg). ｎ 11 represents the actual measured values ​​of the relationship between the standard deviation of the beam width and the beam width. Line 112 represents the regression line obtained from the change in the actual measured values. Line 112 approximately satisfies the relationship of Equation (8).

[0042] In the second embodiment, θ ｎ By setting the value so as to satisfy a predetermined formula, the beam width of the beam emitted by the radio wave control plate can be appropriately controlled.

[0043] Third Embodiment Next, a third embodiment of the present disclosure will be described.

[0044] For the unit structure 10 arranged at the end of the radio wave control board 1, the beam emission direction is θ ０ The phase change amount indicated by the phase gradient in the -Δθ direction and the beam emission direction are ０ It is preferable that the difference between the phase change amount indicated by the phase gradient in the +Δθ direction is 180 degrees or more.

[0045] The amount of phase change of the unit structure according to the third embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram for explaining the amount of phase change of the unit structure according to the third embodiment.

[0046] 5, the horizontal axis represents the element number, and the vertical axis represents the phase change amount [deg]. A line 121 represents the phase change amount [deg] when the beam emission direction is θ ０ The line 122 represents the phase gradient in the +Δθ direction. ０ Represents the phase gradient in the −Δθ direction.

[0047] The difference 131 is the difference between the direction of the beam emitted by the unit structure 10 with element number −N located at the end of the radio wave control plate 1 and ... ０ The phase change amount in the +Δθ direction and θ ０ It represents the difference from the amount of phase change in the −Δθ direction. In the third embodiment, it is preferable that the difference 131 is 180° or more.

[0048] The magnitude of the difference 131 can be changed by translating at least one of the line 121 and the line 122 upward or downward to move the position of the intersection P. For example, the magnitude of the difference 131 can be set to 180° or more by controlling the amount of phase change of each unit feature 10 and translating the line 122 upward.

[0049] The difference 132 is the difference between the direction of the beam emitted by the unit structure 10 with element number N arranged at the end of the radio wave control plate 1 and ... ０ The phase change amount in the +Δθ direction and θ ０ This represents the difference between the amount of phase change in the -Δθ direction. The unit structure 10 with element number N is arranged at the end opposite to the end where the unit structure 10 with element number -N is arranged. In the third embodiment, the magnitude of the difference 132 is also preferably 180° or greater.

[0050] (Beam Shape) The relationship between the amount of phase change and the shape of the beam according to the third embodiment will be described with reference to Fig. 6. Fig. 6 is a diagram for explaining the relationship between the amount of phase change and the shape of the beam according to the third embodiment. In the example shown in Fig. 6, the radio wave control plate 1 emits a beam in a direction of 30°.

[0051] In Figure 6, the horizontal axis represents the transmission direction of the radio wave [deg], and the vertical axis represents the beam intensity [dB]. Figure 6(a) shows the shape of the beam emitted by radio wave control board 1 when difference 131 is 0°. Figure 6(b) shows the shape of the beam emitted by radio wave control board 1 when difference 131 is 28°. Figure 6(c) shows the shape of the beam emitted by radio wave control board 1 when difference 131 is 97°. Figure 6(d) shows the shape of the beam emitted by radio wave control board 1 when difference 131 is 180°.

[0052] 6(a) and 6(b) and 6(c), when difference 131 becomes 97° as in Fig. 6(c), the shape of the beam emitted by radio wave control plate 1 begins to stabilize compared to the cases of Fig. 6(a) and 6(b). As shown in Fig. 6(d), when difference 131 becomes 180°, the shape of the beam emitted by radio wave control plate 1 becomes more stable compared to the case of Fig. 6(c).

[0053] That is, as shown in Figures 6(a) to 6(d), the shape of the beam emitted by radio wave control plate 1 becomes more stable as difference 131 increases from 0° to 180°. Also, although not shown in Figures 6(a) to 6(d), the shape of the beam emitted by radio wave control plate 1 when difference 131 is 180° or more is substantially the same as when difference 131 is 180°. That is, in the third embodiment, by setting difference 131 to 180° or more, the shape of the beam emitted by radio wave control plate 1 can be made more stable.

[0054] [Fourth embodiment] A fourth embodiment will be described. In the fourth embodiment, even when radio wave control plate 1 converges the radio waves received, it is possible to appropriately control the width of the beam emitted by radio wave control plate 1.

[0055] For example, it is assumed that radio wave control plate 1 converges radio waves having a width of 2Δθ to the position of an arbitrary point P. The coordinates of point P can be expressed by the following equation (9).

[0056]

[0057] In equation (9), r is the distance from the center (origin) of the radio wave control board 1 to point P, and φ ０ is the angle (azimuth angle) between the line connecting the origin and point P projected onto the XY plane and the Y axis, and θ ０ represents the angle (zenith angle) between the Z axis and the line obtained by projecting the line connecting the origin and point P onto the XZ plane. In this case, the phase distribution Ψ ｍｎ can be expressed by the following equation (10).

[0058]

[0059] In formula (10), x ｍ represents the coordinate of the m-th unit structure 10 in the x-coordinate, and y ｎ represents the coordinate of the n-th unit feature 10 in the y-coordinate. ｍｎ [θ ０ -Δθ, θ ０ +Δθ]. For example, ｍｎ [θ ０ -Δθ, θ ０ +Δθ], and vary according to uniform random numbers.ｍｎ The method of variation is not limited to uniform random numbers, but may be, for example, random numbers according to a normal distribution.

[0060] [Phase Distribution] The phase distribution of the radio wave control plate according to the fourth embodiment will be described with reference to Fig. 7. Fig. 7 is a diagram for explaining the phase distribution of the radio wave control plate according to the fourth embodiment.

[0061] 7, the horizontal axis represents the element number of the unit structure 10, and the vertical axis represents the transmission phase [deg]. In the example shown in FIG. ｎ [θ ０ -Δθ, θ ０ +Δθ], θ ０ = 30 [deg], Δθ = 5 [deg]. ｍｎ The line 142 represents the phase gradient when θ = 25 [deg] in equation (10). ｍｎ = 35 degrees. Point 143 represents the result of setting the phase of each unit structure 10 according to uniform random numbers in the range of [25 degrees, 35 degrees]. Point 143 is set in the region between line 141 and line 142.

[0062] (Beam Shape) The shape of the beam focused by the radio wave control plate according to the fourth embodiment will be described with reference to Fig. 8. Fig. 8 is a diagram for explaining the shape of the beam focused by the radio wave control plate according to the fourth embodiment. In the example shown in Fig. 8, the radio wave control plate 1 focuses the beam in a direction of 30°.

[0063] In Figure 8, the horizontal axis represents the convergence direction of the radio waves [deg], and the vertical axis represents the beam intensity [dB]. Figure 8(a) shows the shape of the beam focused by the radio wave control plate 1 when Δθ = 0 [deg]. Figure 8(b) shows the shape of the beam focused by the radio wave control plate 1 when Δθ = 5 [deg]. Figure 8(c) shows the shape of the beam focused by the radio wave control plate 1 when Δθ = 10 [deg]. As shown in Figure 8(a), when Δθ = 0 [deg], the beam has a sharp peak in the 30° direction and the beam width is narrow. As shown in Figure 8(b), when Δθ = 5 [deg], the beam shape is wider than in Figure 8(a). As shown in Figure 8(c), when Δθ = 10 [deg], the beam shape is wider than in Figures 8(a) and 8(b).

[0064] 8(a) to 8(c), the shape of the beam focused by radio wave control plate 1 becomes wider as Δθ increases. That is, in the fourth embodiment, by controlling Δθ, the beam width of the beam focused by radio wave control plate 1 can be appropriately controlled.

[0065] (Focal Length) Next, we will explain the relationship between the focal length of radio wave control plate 1 according to the fourth embodiment and the shape of the beam focused by radio wave control plate 1. In the fourth embodiment, the beam shape can be stabilized regardless of the focal length of radio wave control plate 1.

[0066] The relationship between the focal length and the beam shape according to the fourth embodiment will be described with reference to Fig. 9. Fig. 9 is a diagram for explaining the relationship between the focal length and the beam shape according to the fourth embodiment. In the example shown in Fig. 9, the radio wave control plate 1 focuses the beam in a direction of 30°.

[0067] In Fig. 9, the horizontal axis represents the convergence direction [deg] of the radio waves, and the vertical axis represents the beam intensity [dB]. In the example shown in Fig. 9, the focal length is f and the wave number is k. In this case, the focal length normalized by the wave number can be expressed as kf. In the fourth embodiment, whether the focal length is near or far is determined depending on whether kf exceeds the Fresnel distance R. If the length of one side of the radio wave control plate 1 is D, the Fresnel distance R is calculated as follows: ２ / λ.

[0068] Figure 9(a) shows the shape of the beam focused by the radio wave control board 1 when kf = 300. Figure 9(b) shows the shape of the beam focused by the radio wave control board 1 when kf = 1000. Figure 9(c) shows the shape of the beam focused by the radio wave control board 1 when kf = 17000 = Fresnel distance R. That is, Figures 9(a) and 9(b) show the shape of the beam when the focal length of the radio wave control board 1 is close, and Figure 9(c) shows the shape of the beam when the focal length of the radio wave control board 1 is far.

[0069] As shown in Figure 9(a), the shape of the beam focused by the radio wave control plate 1 at a position kf = 300 is stable. As shown in Figure 9(b), the shape of the beam focused by the radio wave control plate 1 at a position kf = 1000 is stable. As shown in Figure 9(c), the shape of the beam focused by the radio wave control plate 1 at a position kf = 17000 is stable. In other words, the shape of the beam focused by the radio wave control plate 1 is stable regardless of the focal length.

[0070] As described above, in the fourth embodiment, the shape of the beam focused by the radio wave control plate 1 can be stabilized regardless of the focal length.

[0071] The present disclosure can also be configured as follows: (1) A predetermined direction θ is detected based on the incident radio wave. ０ a radio wave control plate capable of emitting a beam in a direction perpendicular to the plane of the optical axis, the radio wave control plate including a plurality of unit structures arranged so as to have a gradient of a phase change amount along a first direction, and a phase change amount Ψ of an n-th unit structure (n is an integer) in the first direction; ｎ is set in a region between a first line expressed by formula (1) and a second line expressed by formula (2) in a two-dimensional coordinate system in which the horizontal axis represents the position of the unit structure in the first direction and the vertical axis represents the amount of phase change. ｎ sinθ Ａ ... (1) ky ｎ sinθ Ｂ ...(2) k is the wave number of the radio wave, and y ｎ is the coordinate of the unit feature in the first direction, and θ Ａ <θ０ <θ Ｂ (2) The radio wave control plate emits a beam having a beam width of 2Δθ, and the θ Ａ is θ ０ -Δθ, and the θ Ｂ is θ ０ +Δθ. ｎ The radio wave control board according to (1) or (2), wherein is expressed by the following formula (3): Ψ ｎ =ky ｎ sinθ ｎ ... (3) θ ｎ is [θ ０ -Δθ, θ ０ +Δθ]. (4) The radio wave control board according to (3), wherein the random numbers are uniform random numbers. (5) The radio wave control board according to any one of (1) to (4), wherein in a region where the difference between the phase change amount indicated by the first line and the phase change amount indicated by the second line is 360° or less, the beam width BW of the beam is expressed by the following equation (4): BW=2√3σ[θ ｎ ] (4) In equation (4), σ[θ ｎ ]is θ ｎ (6) The radio wave control board according to (5), wherein in a region where the difference between the amount of phase change indicated by the first line and the amount of phase change indicated by the second line exceeds 360°, the standard deviation is approximately π / √3. (7) The radio wave control board according to any one of (1) to (6), wherein the difference between the amount of phase change indicated by the first line and the amount of phase change indicated by the second line corresponding to a unit structure arranged at at least one of the ends in the first direction among the plurality of unit structures is 180° or more.

[0072] 1 Radio wave control panel 10 Unit structure

Claims

1. Based on the incident radio wave, a predetermined direction θ ０ a radio wave control plate capable of emitting a beam in a direction perpendicular to the plane of the optical axis, the radio wave control plate including a plurality of unit structures arranged so as to have a gradient of a phase change amount along a first direction, and a phase change amount Ψ of an n-th unit structure (n is an integer) in the first direction; ｎ is set in a region between a first line expressed by formula (1) and a second line expressed by formula (2) in a two-dimensional coordinate system in which the horizontal axis represents the position of the unit structure in the first direction and the vertical axis represents the amount of phase change. ｎ sinθ Ａ ... (1) ky ｎ sinθ Ｂ ...(2) k is the wave number of the radio wave, and y ｎ is the coordinate of the unit feature in the first direction, and θ Ａ <θ ０ <θ Ｂ is.

2. The radio wave control plate emits a beam with a beam width of 2Δθ, and Ａ is θ ０ -Δθ, and the θ Ｂ is θ ０ The radio wave control board according to claim 1 , wherein the angle is +Δθ.

3. Psi ｎ The radio wave control board according to claim 1 or 2, wherein is expressed by the following formula (3): Ψ ｎ =ky ｎ sinθ ｎ ... (3) θ ｎ is [θ ０ -Δθ, θ ０ +Δθ].

4. The radio wave control board according to claim 3, wherein the random numbers are uniform random numbers.

5. The radio wave control board according to any one of claims 1 to 4, wherein in an area where the difference between the amount of phase change indicated by the first line and the amount of phase change indicated by the second line is 360° or less, the beam width BW of the beam is expressed by the following formula (4): BW = 2√3σ [θ ｎ ] (4) In equation (4), σ[θ ｎ ]is θ ｎ is the standard deviation of 6. The radio wave control board according to claim 5, wherein in a region where the difference between the phase change amount indicated by the first line and the phase change amount indicated by the second line exceeds 360°, the standard deviation is approximately π / √3.

7. A radio wave control board as described in any one of claims 1 to 6, wherein the difference between the phase change amount indicated by the first line and the phase change amount indicated by the second line corresponding to a unit structure among the plurality of unit structures that is arranged at at least one of the ends in the first direction is 180° or more.

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