radio wave reflector

Abstract

This radio wave reflector comprises a plurality of unit structures that are arranged in a first plane direction, and a plurality of radio wave reflection regions that include the plurality of unit structures and have mutually different reflection angles in a first angular direction and a second angular direction relative to the radio waves.

Description

Technical Field

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

Background Art

[0002] A technique for controlling electromagnetic waves without using a dielectric lens is known. 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.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The radio wave reflector of the present disclosure includes a plurality of unit structures arranged in the first surface direction, and a plurality of radio wave reflection regions including the plurality of unit structures and having different reflection angles for radio waves in the first angular direction and the second angular direction.

Brief Description of the Drawings

[0005] [Figure 1] FIG. 1 is a diagram showing a configuration example of a radio wave reflector according to each embodiment. [Figure 2] FIG. 2 is a diagram for explaining a method of using the radio wave reflector. [Figure 3] FIG. 3 is a diagram showing a configuration example of a radio wave reflector according to the first embodiment. [Figure 4] FIG. 4 is a diagram for explaining the beam width of the reflected wave according to the first embodiment. [Figure 5] FIG. 5 is a diagram showing a configuration example of a radio wave reflector according to the second embodiment. [Figure 6] FIG. 6 is a diagram for explaining a method of reflecting radio waves by a radio wave reflector according to the third embodiment. [Figure 7]Figure 7 is a diagram illustrating the reflection angle of the radio wave reflection region according to the third embodiment. [Figure 8] Figure 8 shows the reflected wave in the first angular direction according to a comparative example of the fourth embodiment. [Figure 9] Figure 9 shows the gain characteristics of the reflected wave in the first angular direction according to a comparative example of the fourth embodiment. [Figure 10] Figure 10 shows the reflected wave in the second angular direction according to a comparative example of the fourth embodiment. [Figure 11] Figure 11 shows the gain characteristics of the reflected wave in the second angular direction according to a comparative example of the fourth embodiment. [Figure 12] Figure 12 shows an example of the configuration of a radio wave reflector according to the fourth embodiment. [Figure 13] Figure 13 shows the gain characteristics of the reflected wave in the first angular direction according to the fourth embodiment. [Figure 14] Figure 14 is a diagram illustrating the reflection angle in the second direction of the radio wave reflector according to the fourth embodiment. [Figure 15] Figure 15 shows the gain characteristics of the reflected wave in the second angular direction according to the fourth embodiment. [Modes for carrying out the invention]

[0006] Embodiments of the present invention will be described in detail below with reference to the attached drawings. However, this embodiment does not limit the present disclosure, and in the following embodiments, the same parts are denoted by the same reference numerals to omit redundant descriptions.

[0007] In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each part will be described while referring to this XYZ orthogonal coordinate system. The direction parallel to the X-axis in the 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 direction and the Y-axis direction are directions parallel to the ground, and the Z-axis direction is the height direction from the ground. Also, the plane including the X-axis and the Y-axis is appropriately referred to as the XY plane, the plane including the X-axis and the Z-axis is appropriately referred to as the XZ plane, and the plane including the Y-axis and the Z-axis is 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.

[0008] [Embodiment] (Radio wave reflector) Using FIG. 1, a configuration example of the radio wave reflector according to each embodiment will be described. FIG. 1 is a diagram showing a configuration example of the radio wave reflector according to each embodiment.

[0009] The radio wave reflector 1a is a plate-like member configured to be transmissive to the radio waves transmitted by the base station. The radio wave reflector 1a is configured to, for example, reflect the radio waves received from the base station at a predetermined angle when receiving the radio waves transmitted by the base station. The radio wave reflector 1a can be configured of, for example, a metamaterial that changes the phase of the incident wave.

[0010] As shown in FIG. 1, the radio wave reflector 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 structure 10a, the unit structure 10b, the unit structure 10c, and the unit structure 10d can be formed on the substrate 2. The substrate 2 can be, for example, a dielectric substrate formed of a dielectric. The substrate 2 can have, for example, a rectangular shape, but is not limited thereto. The unit structure 10a, the unit structure 10b, the unit structure 10c, and the unit structure 10d can be two-dimensionally arranged on the substrate 2. The arrangement method of the unit structure 10a, the unit structure 10b, the unit structure 10c, and the unit structure 10d is also called the phase distribution.

[0012] Specifically, on the substrate 2, a plurality of unit structures 10a can be installed as an example at the lowermost stage of the substrate 2. On the substrate 2, above the stage where the unit structure 10a is installed, a plurality of unit structures 10b can be installed in a row. On the substrate 2, above the stage where the unit structure 10b is installed, a plurality of unit structures 10c can be installed in a row. On the substrate 2, above the stage where the unit structure 10c is installed, a plurality of unit structures 10d can be installed in a row. That is, the radio wave reflector 1 can have a structure in which a plurality of unit structures with different sizes are periodically arranged. The unit structures 10a to 10d can have different frequency bands of radio waves to be changed and amounts of phase change respectively. The unit structures 10a to 10d each have a rectangular shape, but are not limited thereto. By changing the size and shape of the unit structure 10a, the unit structure 10b, the unit structure 10c, and the unit structure 10d, the frequency band of the radio wave to be reflected and the amount of phase change can be adjusted.

[0013] FIG. 2 is a diagram for explaining a method of using the radio wave reflector. As shown in FIG. 2, the radio wave reflector 1a is configured to reflect the radio wave W1 transmitted by the base station 3 at a predetermined angle and emit the reflected wave W2 to the receiving device 4. In the present disclosure, the angle between the straight line obtained by projecting the reflected wave W2 onto the XZ plane and the Z axis is θ, and the angle between the straight line obtained by projecting the reflected wave W2 onto the XY plane and the Y axis is φ. The direction in which the angle θ changes may be referred to as the θ direction, and the direction in which the angle φ changes may be referred to as the φ direction.

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

[0015]

Equation

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

[0018] [First Embodiment] An example of the configuration of a radio wave reflector according to the first embodiment will be explained using Figure 3. Figure 3 is a diagram showing an example of the configuration of a radio wave reflector according to the first embodiment. The radio wave reflector 1 is divided in the Y-axis direction (horizontal direction) in the XY plane.

[0019] As shown in Figure 3, the radio wave reflector 1 includes a first radio wave reflection region 11 and a second radio wave reflection region 12. The radio wave reflector 1 is configured to receive radio waves W1 transmitted by the base station 3 and reflect them toward the vicinity of point C in the XZ plane (reflection surface).

[0020] The first radio wave reflection region 11 and the second radio wave reflection region 12 are regions obtained by dividing the radio wave reflector 1 perpendicularly with respect to the reflective surface. The first radio wave reflection region 11 is configured to emit reflected waves W2-1, which are obtained by reflecting the received radio wave W1, toward the vicinity of point C. The second radio wave reflection region 12 is configured to emit reflected waves W2-2, which are obtained by reflecting the received radio wave W1, toward the vicinity of point C.

[0021] The first radio wave reflection region 11 and the second radio wave reflection region 12 are configured such that the reflection angles of the radio wave W1 are different. The first radio wave reflection region 11 and the second radio wave reflection region 12 are configured such that the reflection angles of the radio wave W1 are different, for example, by configuring their respective phase distributions to be different. In other words, the reflection angles of the radio wave W1 can be set independently for the first radio wave reflection region 11 and the second radio wave reflection region 12. In the first embodiment, by setting the reflection angle of the radio wave W1 for each radio wave reflection region, the beam width in the θ direction of the reflected wave toward point C can be widened.

[0022] Figure 4 is a diagram illustrating the beam width of the reflected wave according to the first embodiment. As shown in Figure 4, the first radio wave reflection region 11 emits the reflected wave W2-1, which has reflected the radio wave W1, toward the vicinity of point C. Region R11 shows the beam width of the reflected wave W2-1 on the hemisphere containing point C. The second radio wave reflection region 12 emits the reflected wave W2-2, which has reflected the radio wave W1, toward the vicinity of point C. Region R12 shows the beam width of the reflected wave W2-2 on the hemisphere containing point C. Region R1 shows the beam width of the reflected wave, which has been reflected by the radio wave reflector 1 from the radio wave W1, on the hemisphere containing point C. Region R1 is the combined region of region R11 and region R12. Regions R11 and R12 are aligned in the θ direction. In other words, the first embodiment can widen the beam width in the θ direction on a hemispherical surface including point C by dividing the radio wave reflector 1 into a plurality of radio wave reflection regions, such as a first radio wave reflection region 11 and a second radio wave reflection region 12.

[0023] The first radio wave reflection region 11 and the second radio wave reflection region 12 may be the same size or different sizes. The first radio wave reflection region 11 and the second radio wave reflection region 12 may be formed, for example, by forming two regions with different phase distributions on a single radio wave reflector 1. The first radio wave reflection region 11 and the second radio wave reflection region 12 may be formed, for example, by arranging two radio wave reflectors with different phase distributions side by side. When the first radio wave reflection region 11 and the second radio wave reflection region 12 are formed with two radio wave reflectors, the two radio wave reflectors may be placed in contact with each other or with a predetermined gap between them.

[0024] In the first embodiment, the radio wave reflector 1 was described as including two radio wave reflection regions, a first radio wave reflection region 11 and a second radio wave reflection region 12, but the present disclosure is not limited thereto. The radio wave reflector 1 may include three or more radio wave reflection regions.

[0025] As described above, in the first embodiment, the radio wave reflector 1 includes a plurality of radio wave reflection regions that are perpendicular to the reflective surface and have different reflection angles of the radio wave W1. This allows the first embodiment to broaden the beam width in the far-field region of the reflected wave reflected by the radio wave reflector 1.

[0026] [Second Embodiment] An example of the configuration of a radio wave reflector according to the second embodiment will be explained using Figure 5. Figure 5 is a diagram showing an example of the configuration of a radio wave reflector according to the second embodiment.

[0027] As shown in Figure 5, the radio wave reflector 1A comprises a first radio wave reflection region 11A, a second radio wave reflection region 12A, a third radio wave reflection region 13A, and a fourth radio wave reflection region 14A. The radio wave reflector 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 reflection region 11A is configured to reflect radio wave W1 and emit the reflected wave W2A-1 toward the vicinity of point C. The second radio wave reflection region 12A is configured to reflect radio wave W1 and emit the reflected wave W2A-2 toward the vicinity of point C. The third radio wave reflection region 13A is configured to reflect radio wave W1 and emit the reflected wave W2A-3 toward the vicinity of point C. The fourth radio wave reflection region 14A is configured to reflect radio wave W1 and emit the reflected wave W2A-4 toward the vicinity of point C.

[0029] The first to fourth radio wave reflection regions 11A to 14A are configured such that the reflection angles of the radio wave W1 are different for each region. The first to fourth radio wave reflection regions 11A to 14A are configured such that the reflection angles of the radio wave W1 are different, for example, by configuring their respective phase distributions to be different. In other words, the reflection angles of the radio wave W1 can be set independently for the first to fourth radio wave reflection regions 11A to 14A. In the second embodiment, by setting the reflection angle of the radio wave W1 for each radio wave reflection region, the beam width in the θ and φ directions of the reflected wave on the hemispherical surface including point C can be widened.

[0030] Region R11A represents the beam width on the hemisphere containing point C of reflected wave W2A-1. Region R12A represents the beam width on the hemisphere containing point C of reflected wave W2A-2. Region R13A represents the beam width on the hemisphere containing point C of reflected wave W2A-3. Region R14A represents the beam width on the hemisphere containing point C of reflected wave W2A-4. Region R1A is the 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. Regions R11A and R12A, and regions R13A and R14A are aligned perpendicular to the reflective surface. Regions R11A and R13A, and regions R12A and R14A are aligned parallel to the reflective surface. In other words, in the second embodiment, by dividing the radio wave reflector 1A into multiple radio wave reflection regions such as the first radio wave reflection region 11A to the fourth radio wave reflection region 14A, the beam width in the θ and φ directions on the hemisphere containing point C can be widened.

[0031] The first to fourth radio wave reflection regions 11A to 14A may each be the same size or different sizes. The first to fourth radio wave reflection regions 11A to 14A may each be formed, for example, by forming four regions with different phase distributions on a single radio wave reflector 1A. The first to fourth radio wave reflection regions 11A to 14 may each be formed, for example, by arranging four radio wave reflectors with different phase distributions. When the first to fourth radio wave reflection regions 11A to 14A are formed with four radio wave reflectors, the four reflectors may be arranged in contact with each other or with a predetermined gap between them.

[0032] In the second embodiment, the radio wave reflector 1A was described as including four radio wave reflection regions, from the first radio wave reflection region 11A to the fourth radio wave reflection region 14A, but the disclosure is not limited thereto. The radio wave reflector 1A may include five or more radio wave reflection regions.

[0033] As described above, in the second embodiment, the radio wave reflector 1A includes multiple radio wave reflection regions that are perpendicular and parallel to the reflective surface and have different reflection angles of the radio wave W1. This allows the second embodiment to more appropriately widen the beam width in the far region of the reflected wave reflected by the radio wave reflector 1A.

[0034] [Third Embodiment] Figure 6 is a diagram illustrating the method of reflecting radio waves using a radio wave reflector according to the third embodiment. For example, if point C, which is the center of region R1A where the reflected wave needs to be widened, is included within the beam width in the θ and φ directions of the reflected waves from each of the first to fourth radio wave reflection regions 11A to 14A, the received power at the position of point C may become unnecessarily large. As a result, the beam width of the reflected wave in the direction of point C may end up being narrowed.

[0035] In the third embodiment, the reflection angle is set such that point C is not included within the beamwidth in both the θ and φ directions of the reflected wave from at least one of the multiple radio wave reflection regions. Furthermore, in the third embodiment, the reflection angle of the radio wave reflection region that emits the reflected wave set so as not to include point C is set so as to overlap within the half-width of the reflected wave from the radio wave reflection region set so as to include point C in both the θ and φ directions.

[0036] Figure 7 is a diagram illustrating the reflection angle of the radio wave reflection region according to the third embodiment. In Figure 7, the horizontal axis shows the reflection angle [deg (degrees)] in the θ direction, and the vertical axis shows the gain [dB (decibels)]. Line 101 indicates the position of point C. Beam pattern 102 shows the gain characteristics of the reflected wave from the radio wave reflection region, where the reflection angle is set so that point C is not included within the beam width. Beam pattern 103 shows the gain characteristics of the reflected wave from the radio wave reflection region, where point C is included within the beam width.

[0037] The half-width 104 represents the half-width of the reflected wave from the radio wave reflection region where the reflection angle is set so that point C is not included within the beamwidth. The half-width 105 represents the half-width of the reflected wave from the radio wave reflection region where the reflection angle is set so that point C is included within the beamwidth. As shown in Figure 7, point C is located outside the half-width 104 and within the half-width 105. Furthermore, the reflected wave from the radio wave reflection region where the reflection angle is set so that point C is not included within the beamwidth and the reflected wave from the region where point C is included within the beamwidth are shown. ru The reflected waves from the radio wave reflection region, where the reflection angle is set accordingly, overlap within the half-widths of 10⁴ and 10⁵.

[0038] As a result, the third embodiment can prevent the received power at point C from becoming unnecessarily large. Consequently, the third embodiment can prevent the beam width on the hemispherical surface including point C from becoming narrower.

[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 reflection angle of the radio wave reflection region, it may not be possible to obtain a flat beam pattern.

[0040] Figure 8 shows a diagram of the reflected wave in the first angular direction according to a comparative example of the fourth embodiment. The first radio wave reflection region 11A and the third radio wave reflection region 13A are sometimes collectively referred to as the first radio wave reflection region group. The second radio wave reflection region 12A and the fourth radio wave reflection region 14A are sometimes collectively referred to as the second radio wave reflection region group. The radio wave reflector 1A is configured to reflect radio waves W1 as a whole and emit the reflected wave W2 in the θ direction.

[0041] The first radio wave reflection region 11A is configured to reflect the radio wave W1 at a 47.7° angle in the θ direction, for example. The second radio wave reflection region 12A is configured to reflect the radio wave W1 at a 52.3° angle in the θ direction, for example. The third radio wave reflection region 13A is configured to reflect the radio wave W1 at a 47.7° angle in the θ direction, for example. The fourth radio wave reflection region 14A is configured to reflect the radio wave W1 at a 52.3° angle in the θ direction, for example.

[0042] Figure 9 shows the gain characteristics of the reflected wave in the first angular direction according to a comparative example of the fourth embodiment. In Figure 9, the horizontal axis represents the reflection angle [deg] and the vertical axis represents the gain [dB]. Beam pattern 110 shows the gain characteristics of the reflected wave in the θ direction from which the entire radio wave reflector 1A is emitted. Beam pattern 111 shows the gain characteristics of the reflected wave in the θ direction from which the first radio wave reflection region is emitted. Beam pattern 112 shows the gain characteristics of the reflected wave in the θ direction from which the second radio wave reflection region is emitted. Beam pattern 110 is a superposition of beam pattern 111 and beam pattern 112.

[0043] As shown by beam pattern 110, in the range 113, which is the angular region where we want to widen the beam width of the reflected wave in the θ direction, the reflected wave does not have a flat beam pattern. This is because beam pattern 111 has a null point P1 and beam pattern 112 has a null point P2. Null points P1 and P2 are located within range 113. Therefore, when beam pattern 111 and beam pattern 112 are superimposed, ripple occurs in beam pattern 110 within range 113, and a flat beam pattern cannot be obtained within range 113.

[0044] Figure 10 shows a reflected wave in the second angular direction according to a comparative example of the fourth embodiment. The first radio wave reflection region 11A and the second radio wave reflection region 12A are sometimes collectively referred to as the third radio wave reflection region group. The third radio wave reflection region 13A and the fourth radio wave reflection region 14A are sometimes collectively referred to as the fourth radio wave reflection region group. The radio wave reflector 1A is configured to reflect radio waves W1 as a whole and emit reflected waves W2 in the φ direction.

[0045] The first radio wave reflection region 11A is configured to reflect the radio wave W1 in a direction of 2.3° in the φ direction, for example. The second radio wave reflection region 12A is configured to reflect the radio wave W1 in a direction of 2.3° in the φ direction, for example. The third radio wave reflection region 13A is configured to reflect the radio wave W1 in a direction of -2.3° in the φ direction, for example. The fourth radio wave reflection region 14A is configured to reflect the radio wave W1 in a direction of -2.3° in the φ direction, for example.

[0046] Figure 11 shows the gain characteristics of the reflected wave in the second angular direction according to a comparative example of the fourth embodiment. In Figure 11, the horizontal axis represents the reflection angle [deg] and the vertical axis represents the gain [dB]. Beam pattern 120 shows the gain characteristics of the reflected wave in the φ direction emitted from the entire radio wave reflector 1A. Beam pattern 121 shows the gain characteristics of the reflected wave in the φ direction emitted from the third radio wave reflection region. Beam pattern 122 shows the gain characteristics of the reflected wave in the φ direction emitted from the fourth radio wave reflection region. Beam pattern 120 is a superposition of beam pattern 121 and beam pattern 122.

[0047] As shown by beam pattern 120, in the angular region 123, where we want to widen the beam width of the reflected wave in the φ direction, the reflected wave does not form a flat beam pattern. This is because beam pattern 121 has a null point P3 and beam pattern 122 has a null point P4. Null points P3 and P4 are located within the region 123. Therefore, when beam pattern 121 and beam pattern 122 are superimposed, ripple occurs in beam pattern 120 within the region 123, and a flat beam pattern cannot be obtained within the region 123.

[0048] Therefore, in the fourth embodiment, a reflected wave having a flat beam pattern is formed by appropriately setting the aperture size of each radio wave reflection region.

[0049] Here, if we let λ be the wavelength of the reflected wave, d be the aperture size of each radio wave reflection region, α be the angle of the first null on the high-frequency side, and β be the angle of the first null on the low-frequency side, then the following equation (2) holds.

[0050]

number

[0051] Let Δθ be the range over which we want to create a flat beam pattern. In this case, since we only need to form the beam pattern between the high-frequency fast null and the low-frequency fast null, the following equation (3) holds true.

[0052]

number

[0053] When equation (3) holds, the null points of the reflected waves emitted from each radio wave reflection region will no longer fall within the angular region where a flat beam pattern is desired. In other words, by setting the aperture size of each radio wave reflection region to satisfy the following equation (4), a flat beam pattern can be formed within the desired range.

[0054]

number

[0055] The examples shown in Figures 9 to 11 represent the gain characteristics of a radio wave reflector that does not satisfy equation (4). As a result, a flat beam pattern is not obtained in ranges 113 and 123.

[0056] An example of the configuration of a radio wave reflector according to the fourth embodiment will be explained using Figure 12. Figure 12 is a diagram showing an example of the configuration of a radio wave reflector according to the fourth embodiment. As shown in Figure 12, the radio wave reflector 1B comprises a first radio wave reflection region 11B-1, a first radio wave reflection region 11B-2, a first radio wave reflection region 11B-3, a first radio wave reflection region 11B-4, a second radio wave reflection region 12B-1, a second radio wave reflection region 12B-2, a second radio wave reflection region 12B-3, a second radio wave reflection region 12B-4, a third radio wave reflection region 13B-1, a third radio wave reflection region 13B-2, a third radio wave reflection region 13B-3, a third radio wave reflection region 13B-4, a fourth radio wave reflection region 14B-1, a fourth radio wave reflection region 14B-2, a fourth radio wave reflection region 14B-3, and a fourth radio wave reflection region 14B-4. In other words, the radio wave reflector 1B has 16 radio wave reflection regions. The radio wave reflector 1B is configured to reflect radio waves W1 using the 16 radio wave reflection regions and emit reflected waves W2. The radio wave reflector 1B is divided in both the X-axis direction (vertical direction) and the Y-axis direction (horizontal direction) in the XY plane. The size of the opening of each radio wave reflection region is determined to satisfy equation (4).

[0057] The first radio wave reflection region 11B-1 is configured to reflect the radio wave W1 in a direction of 44.8° in the θ direction, for example. The first radio wave reflection region 11B-2 is configured to reflect the radio wave W1 in a direction of 44.8° in the θ direction, for example. The first radio wave reflection region 11B-3 is configured to reflect the radio wave W1 in a direction of 44.8° in the θ direction, for example. The first radio wave reflection region 11B-4 is configured to reflect the radio wave W1 in a direction of 44.8° in the θ direction, for example.

[0058] The second radio wave reflection region 12B-1 is configured, for example, to reflect the radio wave W1 in a direction of 49.65° in the θ direction. The second radio wave reflection region 12B-2 is configured, for example, to reflect the radio wave W1 in a direction of 49.65° in the θ direction. The second radio wave reflection region 12B-3 is configured, for example, to reflect the radio wave W1 in a direction of 49.65° in the θ direction. The second radio wave reflection region 12B-4 is configured, for example, to reflect the radio wave W1 in a direction of 49.65° in the θ direction.

[0059] The third radio wave reflection region 13B-1 is configured, for example, to reflect the radio wave W1 in the θ direction at a 50.35° angle. The third radio wave reflection region 13B-2 is configured, for example, to reflect the radio wave W1 in the θ direction at a 50.35° angle. The third radio wave reflection region 13B-3 is configured, for example, to reflect the radio wave W1 in the θ direction at a 50.35° angle. The third radio wave reflection region 13B-4 is configured, for example, to reflect the radio wave W1 in the θ direction at a 50.35° angle.

[0060] The fourth radio wave reflection region 14B-1 is configured, for example, to reflect the radio wave W1 in a direction of 56.2° in the θ direction. The fourth radio wave reflection region 14B-2 is configured, for example, to reflect the radio wave W1 in a direction of 56.2° in the θ direction. The fourth radio wave reflection region 14B-3 is configured, for example, to reflect the radio wave W1 in a direction of 56.2° in the θ direction. The fourth radio wave reflection region 14B-4 is configured, for example, to reflect the radio wave W1 in a direction of 56.2° in the θ direction.

[0061] The first radio wave reflection region 11B-1, the first radio wave reflection region 11B-2, the first radio wave reflection region 11B-3, and the first radio wave reflection region 11B-4 are sometimes collectively referred to as the first radio wave reflection region group. The second radio wave reflection region 12B-1, the second radio wave reflection region 12B-2, the second radio wave reflection region 12B-3, and the second radio wave reflection region 12B-4 are sometimes collectively referred to as the second radio wave reflection region group. The third radio wave reflection region 13B-1, the third radio wave reflection region 13B-2, the third radio wave reflection region 13B-3, and the third radio wave reflection region 13B-4 are sometimes collectively referred to as the third radio wave reflection region group. The fourth radio wave reflection region 14B-1, the fourth radio wave reflection region 14B-2, the fourth radio wave reflection region 14B-3, and the fourth radio wave reflection region 14B-4 are sometimes collectively referred to as the fourth radio wave reflection region group.

[0062] Figure 13 shows the gain characteristics of the reflected wave in the first angular direction according to the fourth embodiment. In Figure 13, the horizontal axis represents the reflection angle [deg] in the θ direction, and the vertical axis represents the gain [dB]. Beam pattern 130 shows the gain characteristics of the reflected wave in the θ direction emitted by the entire radio wave reflector 1B. Beam pattern 131 shows the gain characteristics of the reflected wave emitted by the first group of radio wave reflection regions. Beam pattern 132 shows the gain characteristics of the reflected wave emitted by the second group of radio wave reflection regions. Beam pattern 133 shows the gain characteristics of the reflected wave emitted by the third group of radio wave reflection regions. Beam pattern 134 shows the gain characteristics of the reflected wave emitted by the fourth group of radio wave reflection regions. Beam pattern 130 is a superposition of beam pattern 131, beam pattern 132, beam pattern 133, and beam pattern 134. In the fourth embodiment, as shown by beam pattern 130, the radio wave reflector 1B can emit reflected waves of a flat beam pattern in the range 135 between the peak angle of beam pattern 131 and the peak angle of beam pattern 134.

[0063] Figure 14 is a diagram illustrating the reflection angle in the second direction of the radio wave reflector according to the fourth embodiment.

[0064] The first radio wave reflection region 11B-1 is configured to reflect the radio wave W1 in the φ direction at a -4° angle, for example. The first radio wave reflection region 11B-2 is configured to reflect the radio wave W1 in the φ direction at a -0.35° angle, for example. The first radio wave reflection region 11B-3 is configured to reflect the radio wave W1 in the φ direction at a 0.4° angle, for example. The first radio wave reflection region 11B-4 is configured to reflect the radio wave W1 in the φ direction at a 4° angle, for example.

[0065] The second radio wave reflection region 12B-1 is configured to reflect the radio wave W1 in the φ direction at a -4° angle, for example. The second radio wave reflection region 12B-2 is configured to reflect the radio wave W1 in the φ direction at a -0.35° angle, for example. The second radio wave reflection region 12B-3 is configured to reflect the radio wave W1 in the φ direction at a 0.4° angle, for example. The second radio wave reflection region 12B-4 is configured to reflect the radio wave W1 in the φ direction at a 4° angle, for example.

[0066] The third radio wave reflection region 13B-1 is configured, for example, to reflect the radio wave W1 in the φ direction at a -4° angle. The third radio wave reflection region 13B-2 is configured, for example, to reflect the radio wave W1 in the φ direction at a -0.35° angle. The third radio wave reflection region 13B-3 is configured, for example, to reflect the radio wave W1 in the φ direction at a 0.4° angle. The third radio wave reflection region 13B-4 is configured, for example, to reflect the radio wave W1 in the φ direction at a 4° angle.

[0067] The fourth radio wave reflection region 14B-1 is configured, for example, to reflect the radio wave W1 in the φ direction at a -4° angle. The fourth radio wave reflection region 14B-2 is configured, for example, to reflect the radio wave W1 in the φ direction at a -0.35° angle. The fourth radio wave reflection region 14B-3 is configured, for example, to reflect the radio wave W1 in the φ direction at a 0.4° angle. The fourth radio wave reflection region 14B-4 is configured, for example, to reflect the radio wave W1 in the φ direction at a 4° angle.

[0068] The first radio wave reflection region 11B-4, the second radio wave reflection region 12B-4, the third radio wave reflection region 13B-4, and the fourth radio wave reflection region 14B-4 are sometimes collectively referred to as the fifth radio wave reflection region group. The first radio wave reflection region 11B-3, the second radio wave reflection region 12B-3, the third radio wave reflection region 13B-3, and the fourth radio wave reflection region 14B-3 are sometimes collectively referred to as the sixth radio wave reflection region group. The first radio wave reflection region 11B-2, the second radio wave reflection region 12B-2, the third radio wave reflection region 13B-2, and the fourth radio wave reflection region 14B-2 are sometimes collectively referred to as the seventh radio wave reflection region group. The first radio wave reflection region 11B-1, the second radio wave reflection region 12B-1, the third radio wave reflection region 13B-1, and the fourth radio wave reflection region 14B-1 are sometimes collectively referred to as the eighth radio wave reflection region group.

[0069] Figure 15 shows the gain characteristics of the reflected wave in the second angular direction according to the fourth embodiment. In Figure 15, the horizontal axis represents the reflection angle [deg] in the φ direction, and the vertical axis represents the gain [dB]. Beam pattern 140 shows the gain characteristics of the reflected wave in the φ direction emitted from the entire radio wave reflector 1B. Beam pattern 141 shows the gain characteristics of the reflected wave emitted from the fifth radio wave reflection region group. Beam pattern 142 shows the gain characteristics of the reflected wave emitted from the sixth radio wave reflection region group. Beam pattern 143 shows the gain characteristics of the reflected wave emitted from the seventh radio wave reflection region group. Beam pattern 144 shows the gain characteristics of the reflected wave emitted from the eighth radio wave reflection region group. Beam pattern 140 is a superposition of beam pattern 141, beam pattern 142, beam pattern 143, and beam pattern 144. In the fourth embodiment, as shown by beam pattern 140, the radio wave reflector 1B can emit reflected waves of a flat beam pattern in the range 145 between the peak angle of beam pattern 141 and the peak angle of beam pattern 144.

[0070] Here, the angles of the peak point and null point of beam pattern 131 are defined as θ, respectively. a and θ a1H Let's assume that the angles of the peak point and null point of beam pattern 134 are θ, respectively.d and θ d1L Let's assume that the range 135 is Δθ, then Δθ is expressed by the following equation (5).

[0071]

number

[0072] Generally, if the peak angle is γ, the first null angle is β, the wavelength of the reflected wave is λ, and the size of the aperture is d, then the following equation (6) holds.

[0073]

number

[0074] Since equation (6) holds, if we let θ be the angle of the center over which we want to spread the reflected wave, then if the range over which we want to flatten the reflected wave is determined, then θ a and θ d The desired beam pattern can be obtained by determining this based on the following equation (7).

[0075]

number

[0076] 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 This can be calculated. The same applies to equations (5) through (7) in the φ direction, so the explanation is omitted.

[0077] As described above, the fourth embodiment can calculate the size of the aperture based on the angle of the null point of the reflected wave emitted from each radio wave reflection region. Then, based on the calculated size of the aperture, the fourth embodiment can calculate the angle of the peak point of the reflected wave emitted from each radio wave reflection region. As a result, the fourth embodiment can form a flatter beam pattern more appropriately within a desired range.

[0078] While embodiments of the present disclosure have been described above, the present disclosure is not limited by the content of these embodiments. Furthermore, the aforementioned components include those that are readily conceivable to those skilled in the art, those that are substantially identical, and those that fall within the so-called equivalent range. Moreover, the aforementioned components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the embodiments described above. [Explanation of symbols]

[0079] 1,1a,1A,1B Radio wave reflector 3 base station 4. Receiving device 10a, 10b, 10c, 10d Unit Structure 11,11A,11B 1st radio wave reflection area 12,12A,12B 2nd radio wave reflection area 13A,13B 3rd radio wave reflection area 14A,14B 4th radio wave reflection area

Claims

1. Multiple unit structures arranged on the first surface, A plurality of the aforementioned unit structures are included, and the reflection angles of the radio waves reflected in a first angular direction with respect to the incident radio wave and the radio waves reflected in a second angular direction are different from each other, Includes, The multiple radio wave reflection regions are, In the first or second angular direction, at least one first region is formed such that the point that is the center of the region to be widened of the first reflected wave is not included within the half-width of the first reflected wave obtained by reflecting the radio wave toward the direction of a point in the reflecting surface, The invention comprises at least one second region formed such that the point, which is the center of the region to which the second reflected wave is to be widened, is included within the half-power width of the second reflected wave obtained by reflecting the radio wave toward the point in the first or second angular direction, The first region is formed such that the first reflected wave overlaps with the second reflected wave within the full width at half maximum. Radio wave reflector.

2. The multiple radio wave reflection regions are regions divided in both the vertical and horizontal directions. The radio wave reflector according to claim 1.

3. The size d of the apertures of the multiple radio wave reflection regions satisfies the following equation (1), where λ is the wavelength of the radio wave, α is the angle of the first null point on the high frequency side, β is the angle of the first null point on the low frequency side, and Δθ is the range over which a flat beam pattern is desired. A radio wave reflector according to claim 1 or 2. α-β=2sin －１ (λ / d) ・・・(1)

4. The multiple radio wave reflection regions are formed such that the reflected wave of the entire multiple radio wave reflection regions is flat between the first null point on the low-frequency side of the reflected wave with the smallest reflection angle and the first null point on the high-frequency side of the reflected wave with the largest reflection angle. The radio wave reflector according to claim 3.

5. The reflection angles of the peak of the reflected wave with the smallest reflection angle and the reflection angle of the first null point on the high-frequency side are defined as θ, respectively. ａ and θ ａ１Ｈ The peak of the reflected wave with the largest reflection angle of the aforementioned radio wave and the reflection angle of the first null point on the low-frequency side are defined as θ, respectively. ｄ and θ ｄ１Ｌ Δθ = θ ａ１Ｈ -θ ｄ１Ｌ In that case, the following equation (2) is satisfied: The radio wave reflector according to claim 3. i α =θ+Δθ / 2-sin －１ (λ / d), i ｄ =θ+Δθ / 2+sin －１ (λ / d) ・・・(2)

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