Communication system, radio wave refraction plate, and method for calculating the installation position of the radio wave refraction plate

Abstract

This communication system comprises: a base station that is configured to transmit and receive radio waves; a terminal that is configured to transmit and receive the radio waves to and from the base station; and a plurality of radio wave refraction plates that are placed on the same plane between the base station and the terminal and that are configured to refract and emit the radio waves toward the terminal as refracted radio waves when the radio waves transmitted from the base station go through the refraction plates.

Description

[Technical Field]

[0001] The present disclosure relates to a communication system, a radio wave refraction plate, and a method for calculating the installation position of the radio wave refraction plate. [Background technology]

[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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-231182 Summary of the Invention

[0004] The communication system of the present disclosure includes a base station configured to transmit and receive radio waves, a terminal configured to transmit and receive the radio waves between the base station, and a plurality of radio wave refraction plates installed on the same plane between the base station and the terminal, configured to refract the radio waves transmitted from the base station toward the terminal when the radio waves pass through and emit the refracted radio waves.

[0005] The radio wave refraction plates of the present disclosure are installed in multiple locations on the same plane between a base station configured to transmit and receive radio waves and a terminal configured to transmit and receive the radio waves between the base station, and are configured to refract the radio waves transmitted from the base station toward the terminal when the radio waves pass through the terminal and emit them as refracted radio waves.

[0006] The method for calculating the installation positions of radio wave refraction plates of the present disclosure includes the steps of: calculating a geometric center of the central points of multiple installed radio wave refraction plates; setting a plane that passes through the geometric center and is perpendicular to a line connecting a transmitting point that transmits radio waves to the multiple radio wave refraction plates and a receiving point that receives the radio waves refracted by the radio wave refraction plates; projecting the multiple radio wave refraction plates onto the plane; and calculating installation positions of the multiple radio wave refraction plates so that the area of ​​the multiple radio wave refraction plates included in odd-order Fresnel zones on the plane is larger than the area of ​​the multiple radio wave refraction plates included in even-order Fresnel zones. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram schematically illustrating an example of a radio wave refraction plate. [Figure 3] FIG. 3 is a diagram for explaining a radio wave receiving method according to a comparative example of this embodiment. [Figure 4] FIG. 4 is a diagram for explaining a radio wave receiving method according to a comparative example of this embodiment. [Figure 5] FIG. 5 is a diagram for explaining a radio wave receiving method according to this embodiment. [Figure 6] FIG. 6 is a diagram for explaining a radio wave receiving method according to this embodiment. [Figure 7] FIG. 7 is a diagram for explaining a method for installing a radio wave refraction plate according to this embodiment. [Figure 8] FIG. 8 is a diagram for explaining the Fresnel zone according to this embodiment. [Figure 9] FIG. 9 is a flowchart showing the flow of a process for calculating the installation position of the radio wave refraction plate according to this embodiment. [Figure 10] FIG. 10 is a diagram for explaining the angle dependency of the received power according to the comparative example. [Figure 11] FIG. 11 is a diagram for explaining the angle dependency of the received power according to the embodiment. [Figure 12] FIG. 12 is a diagram for explaining the transmission characteristics of adjacently placed radio wave refraction plates according to the embodiment. [Figure 13] FIG. 13 is a diagram for explaining the transmission characteristics of adjacently placed radio wave refraction plates according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] 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.

[0009] In the following explanation, an XYZ Cartesian coordinate system is set, and the positional relationship of each part will be explained 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. The plane including the X axis and Y axis will be referred to as the XY plane as appropriate. The plane including the X axis and Z axis will be referred to as the XZ plane as appropriate. The plane including the Y axis and Z axis will be referred to as the YZ plane as appropriate. The XY plane is parallel to the horizontal plane. The XY plane, XZ plane, and YZ plane are perpendicular to each other.

[0010] [Embodiment] An example of the configuration of a communication system according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of a communication system according to an embodiment.

[0011] 1, the communication system 1 includes a base station 10, a terminal 12, and a plurality of radio wave refraction plates 14. The communication system 1 may be a communication system compatible with millimeter wave communication capable of performing large-capacity data communication at high speed, such as a fifth-generation mobile communication system (hereinafter also referred to as "5G") or a sixth-generation mobile communication system (hereinafter also referred to as "6G").

[0012] The base station 10 is a wireless communication device configured to transmit and receive radio waves to and from various external devices. The base station 10 is configured to perform wireless communication with the terminal 12, for example, by transmitting and receiving radio waves compatible with 5G or 6G to and from the terminal 12. In this embodiment, the base station 10 is configured to perform wireless communication with the terminal 12 via a plurality of radio wave refraction plates 14 installed on the same plane.

[0013] The terminal 12 is a wireless communication device configured to transmit and receive radio waves to and from various external devices. The terminal 12 is configured to perform wireless communication with the base station 10, for example, by transmitting and receiving radio waves compatible with 5G or 6G between the base station 10 and the terminal 12. In this embodiment, the terminal 12 is configured to perform wireless communication with the base station 10 via a plurality of radio wave refraction plates 14 installed on the same plane. An example of the terminal 12 is a smartphone used by a user, but the present disclosure is not limited thereto. The terminal 12 may be, for example, a relay device that relays communication between the base station 10 and the smartphone used by the user.

[0014] The radio wave refraction plate 14 is a plate-like member configured to allow radio waves transmitted by the base station 10 to pass through. The radio wave refraction plate 14 is configured, for example, to receive radio waves transmitted by the base station 10, refract the radio waves at a predetermined angle, and emit the refracted radio waves. Specifically, the radio wave refraction plate 14 is configured, when it receives radio waves transmitted by the base station 10, to refract the radio waves in the direction of the terminal 12, and emit the radio waves toward the terminal 12. The radio wave refraction plate 14 can be configured, for example, from a metamaterial that changes the phase of incident light.

[0015] Fig. 2 is a diagram schematically illustrating an example of the radio wave refraction plate 14. As shown in Fig. 2, the radio wave refraction plate 14 may include, for example, a substrate 20, an element 22, an element 24, an element 26, and an element 28.

[0016] The elements 22, 24, 26, and 28 may be formed on the substrate 20. The substrate 20 may have, for example, a rectangular shape, but is not limited to this. The elements 22, 24, 26, and 28 may be two-dimensionally arranged on the substrate 20. Specifically, in FIG. 2 , a plurality of elements 22 may be arranged in a line on the bottom level of the substrate 20. A plurality of elements 24 may be arranged in a line on the level above the level on which the elements 22 are arranged on the substrate 20. A plurality of elements 26 may be arranged in a line on the level above the level on which the elements 24 are arranged on the substrate 20. A plurality of elements 28 may be arranged in a line on the level above the level on which the elements 26 are arranged on the substrate 20. In other words, the radio wave refraction plate 14 may have a structure in which a plurality of elements of different sizes are periodically arranged. The elements 22 to 28 may each vary in the frequency band and the amount of phase change of the radio waves they change. Each of elements 22 to 28 has a rectangular shape, but is not limited to this. By changing the size and shape of elements 22, 24, 26, and 28, the frequency band and the amount of phase change of the refracted radio waves can be adjusted.

[0017] As shown in FIG. 1 , in this embodiment, the communication system 1 includes a plurality of radio wave refraction plates 14. The plurality of radio wave refraction plates 14 may be installed within the same plane 16. In the example shown in FIG. 1 , four radio wave refraction plates 14 are installed on the plane 16, but this is merely an example and does not limit the present disclosure. The plane 16 may be space or the surface of a transparent structure such as window glass. The plurality of radio wave refraction plates 14 refract a radio wave W1 transmitted from the base station 10 and output the refracted radio wave W2 to the terminal 12.

[0018] [Comparative Example] Before describing the embodiment, a radio wave receiving method according to a comparative example of the embodiment will be described. Explain In the comparative example, a method is shown in which radio waves from a base station 10 are reflected and received by a terminal 12.

[0019] The example shown in FIG. 3 illustrates two radio wave reflectors: radio wave reflector 30-1 and radio wave reflector 30-2. Radio wave reflector 30-1 and radio wave reflector 30-2 are configured to reflect radio waves W1 transmitted from base station 10 at a predetermined angle as reflected radio waves W3. In FIG. 3, the arrows attached to radio waves W1 and reflected radio waves W3 indicate the directions of travel of radio waves W1 and reflected radio waves W3, respectively. Radio wave reflector 30-1 and radio wave reflector 30-2 are installed at an interval along the Z-axis direction at origin O so that the phases of the reflected radio waves W3 reflected from each other are reinforced. In the example shown in FIG. 3, for example, at a position on straight line 41 in the ZX plane, the reflected radio waves W3 reflected by radio wave reflector 30-1 and the reflected radio waves W3 reflected by radio wave reflector 30-2 are in phase. That is, the received power of the radio wave W3 reflected by the radio wave reflector 30-1 and the received power of the radio wave W3 reflected by the radio wave reflector 30-2 are reinforced at a position on the straight line 41 in the ZX plane.

[0020] FIG. 4 shows an example in which, assuming that the wavelength of radio wave W1 is λ, radio wave reflector 30-2 is shifted by λ / 4 from origin O toward the positive side of the X-axis. For example, when λ is 28 GHz (gigahertz), λ / 4 corresponds to 2.7 mm (millimeters). In this case, as shown in FIG. 4, at a position on straight line 41 in the ZX plane, the reflected radio wave W3 reflected by radio wave reflector 30-1 and the reflected radio wave W3 reflected by radio wave reflector 30-2 are out of phase with each other. That is, at a position on straight line 41 in the ZX plane, the reflected radio wave W3 reflected by radio wave reflector 30-1 and the reflected radio wave W3 reflected by radio wave reflector 30-2 destructively receive power. As such, even if multiple radio wave reflectors are used to increase the area of ​​the reflectors, the reflected radio waves do not necessarily reinforce each other, and there are cases in which the received power is not improved.

[0021] Next, a radio wave receiving method according to this embodiment will be described. Figures 5 and 6 show the radio wave receiving method according to this embodiment. Explain This is a diagram for clarification.

[0022] 5, two reflectors, a radio wave refraction plate 14-1 and a radio wave refraction plate 14-2, are shown. The radio wave refraction plate 14-1 and the radio wave refraction plate 14-2 refract the radio wave W1 transmitted from the base station 10 as a refracted radio wave W2 at a predetermined angle θ. Refracted and emitted as refracted radio waves 5, the arrows attached to the radio wave W1 and the refracted radio wave W2 indicate the traveling directions of the radio wave W1 and the refracted radio wave W2, respectively. The radio wave refraction plate 14-1 and the radio wave refraction plate 14-2 are installed at the origin O along the Z-axis direction with a gap therebetween so as to reinforce the phases of the refracted radio waves W2 refracted by each other. In the example shown in FIG. 5, for example, at a position on a straight line 42 in the ZX plane, the refracted radio wave W2 refracted by the radio wave refraction plate 14-1 and the refracted radio wave W2 refracted by the radio wave refraction plate 14-2 are in phase. In other words, the refracted radio wave W2 refracted by the radio wave refraction plate 14-1 and the refracted radio wave W2 refracted by the radio wave refraction plate 14-2 are in phase with each other along the straight line 42 in the ZX plane. 4 At positions above 2, the received power is constructive.

[0023] 6 shows an example in which the radio wave refraction plate 14-2 is displaced by λ / 4 from the origin O in the positive direction of the X axis, where λ is the wavelength of the radio wave W1. In this embodiment, as shown in FIG. 6, even if the radio wave refraction plate 14-2 is displaced in the positive direction of the X axis, the path length remains almost unchanged. Therefore, in this embodiment, even if the radio wave refraction plate 14-2 is displaced in the positive direction of the X axis, the phases of the refracted radio wave W2 refracted by the radio wave refraction plate 14-1 and the refracted radio wave W2 refracted by the radio wave refraction plate 14-2 are in phase at a position on the straight line 32 in the ZX plane. In other words, in this embodiment, the received power is not weakened, so that multiple radio waves refraction Using a board refraction By increasing the area of ​​the plate, the received power can be improved.

[0024] In this embodiment, when the distance between the radio wave refraction plate 14-1 and the radio wave refraction plate 14-2 is s and the refraction angle of the refracted radio wave W2 is θ, it is preferable that the deviation in the thickness direction (X-axis direction in FIG. 6) between the radio wave refraction plate 14-1 and the radio wave refraction plate 14-2 is s / tan θ or less. By making the deviation in the thickness direction (X-axis direction in FIG. 5) between the radio wave refraction plate 14-1 and the radio wave refraction plate 14-2 s / tan θ or less, the received power can be improved.

[0025] [How to install the radio wave refraction plate] Next, a method for installing the radio wave refraction plate according to this embodiment will be described. Fig. 7 is a diagram for explaining a method for installing the radio wave refraction plate according to this embodiment.

[0026] In this embodiment, when considering the path of radio waves from transmission point T through points on the radio wave refraction plate 14 to reception point R, the radio wave refraction plate 14 is installed so that the area installed in the region where the radio waves constructively interact is larger than the area installed in the region where the radio waves destructively interact. This makes it possible to obtain higher received power in this embodiment. In this embodiment, the region where the radio waves constructively interact is called an odd-order Fresnel zone, and the region where the radio waves destructively interact is called an even-order Fresnel zone.

[0027] (Fresnel zone) The definition of the Fresnel zone according to this embodiment will be explained. As shown in FIG. 7, consider a situation in which radio waves from a transmission point T pass through multiple radio wave refraction plates 14 and reach a reception point R. The transmission point T indicates the position of the antenna of the base station 10, and the reception point R indicates the position of the antenna of the terminal 12. In FIG. 7, the geometric center (center of gravity) of the central points of the multiple radio wave refraction plates 14 is defined as the geometric center C. The linear distance between the transmission point T and the geometric center C is defined as d1. The distance between the reception point R and the geometric center C is defined as d2. Consider a plane P that passes through the geometric center C and is perpendicular to the line TR connecting the transmission point T and the reception point R. Here, consider a circle on the plane P that is centered at the geometric center C and whose radius is defined by the following equation (1).

[0028]

number

[0029] In equation (1), n ​​is a natural number and λ is the wavelength of the radio wave.

[0030] 8 is a diagram for explaining the Fresnel zone according to this embodiment. In this embodiment, in the formula (1), the radius R n-1 from radius R n The annular portion in this range is defined as the n-th Fresnel zone. In the example shown in Fig. 8, a first Fresnel zone 50, a second Fresnel zone 52, a third Fresnel zone 54, and a fourth Fresnel zone 56 are shown.

[0031] A method for calculating the installation position of the radio wave refraction plate according to this embodiment will be described with reference to Fig. 8 and Fig. 9. Fig. 9 is a flowchart showing the flow of processing for calculating the installation position of the radio wave refraction plate according to this embodiment.

[0032] The process shown in FIG. 9 is executed by, for example, an information processing device such as a personal computer (not shown).

[0033] The information processing device calculates the geometric center C of the central points of the installed radio wave refraction plates 14 (step S10), and then proceeds to step S12.

[0034] The information processing device sets a plane P that passes through the geometric center C and is perpendicular to the line TR that connects the transmission point T and the reception point R (step S12), and then proceeds to step S14.

[0035] The information processing device projects a plurality of radio wave refraction plates 14 onto the plane P (step S14), and then proceeds to step S16.

[0036] The information processing device calculates the installation positions of the multiple radio wave refraction plates 14 (step S16). Specifically, the information processing device calculates the installation positions of the multiple radio wave refraction plates 14 so that the area of ​​the radio wave refraction plates 14 included in the odd-order Fresnel zones is larger than the area of ​​the radio wave refraction plates 14 included in the even-order Fresnel zones. More specifically, in the example shown in Fig. 7, the information processing device calculates the installation positions of the multiple radio wave refraction plates 14 so that the area of ​​the radio wave refraction plates 14 included in the first Fresnel zone 50 and the third Fresnel zone 54 is larger than the area of ​​the radio wave refraction plates 14 included in the second Fresnel zone 52 and the fourth Fresnel zone 56. Then, the process proceeds to step S18.

[0037] The information processing device outputs installation position information regarding the installation positions of the plurality of radio wave refraction plates 14 (step S18). This allows the user to adjust the installation positions of the plurality of radio wave refraction plates 14 based on the installation position information.

[0038] (Distance setting method) Next, a method for setting the distance between the terminal 12 according to this embodiment and the plurality of radio wave refraction plates 14 will be described.

[0039] In the vicinity area where the distance from the radio wave refraction plate 14 is sufficiently short compared to the long side of the radio wave refraction plate 14, the beam width of the refracted radio waves from the radio wave refraction plate 14 is wide and the power is dispersed, making it difficult to obtain high reception power. Let d2 be the linear distance between the geometric center C of the central points of the multiple radio wave refraction plates 14 and the reception point R, and L be the sum of the maximum dimensions (for example, diagonals) of the installed multiple radio wave refraction plates 14. sum Then, it is preferable that d2 satisfies the following formula (2).

[0040]

number

[0041] When the linear distance d2 satisfies the formula (2), the beam width of the refracted radio wave becomes narrower, and higher received power can be obtained compared to when only one radio wave refraction plate 14 is installed.

[0042] (Angle dependence of received power) The angle dependency of the received power will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a diagram for explaining the angle dependency of the received power according to a comparative example. Fig. 11 is a diagram for explaining the angle dependency of the received power according to the embodiment.

[0043] Figure 10 shows the angular dependence of the received power when the above formula (2) is not satisfied. Specifically, Figure 10 shows the case where d2 is 0.75 m and L sum The figure shows the angular dependence of the received power when λ is 0.6 m and λ is 28 GHz.

[0044] FIG. 10 shows waveforms 101 and 102. In FIG. 10, the horizontal axis represents the refraction angle [deg (degrees)] and the vertical axis represents the gain [dB]. Waveform 101 shows the angular dependency of the received power when one radio wave refraction plate 14 is installed. Waveform 102 shows the angular dependency of the received power when two radio wave refraction plates 14 are installed. As shown by waveforms 101 and 102, the power distribution of the refracted radio waves becomes wider by installing two radio wave refraction plates 14.

[0045] Figure 11 shows the angular dependence of the received power when the above formula (2) is satisfied. Specifically, Figure 11 shows the case where d2 is 5.0 m and L sum The figure shows the angular dependence of the received power when λ is 0.6 m and λ is 28 GHz.

[0046] Fig. 11 shows waveforms 103 and 104. In Fig. 11, the horizontal axis represents the refraction angle [deg] and the vertical axis represents the gain [dB]. Waveform 103 shows the angular dependency of the received power when one radio wave refraction plate 14 is installed. Waveform 104 shows the angular dependency of the received power when two radio wave refraction plates 14 are installed. As shown by waveforms 103 and 104, installing two radio wave refraction plates 14 improves the gain of the received power and narrows the power distribution.

[0047] That is, as shown in FIGS. 10 and 11, when d2 satisfies the condition of the above formula (2), higher reception power can be obtained by installing a plurality of radio wave refraction plates 14.

[0048] (relative relationship) Next, a preferred installation method for installing a plurality of radio wave refraction plates 14 adjacent to other radio wave refraction plates 14 will be described.

[0049] 12 and 13 are diagrams for explaining the transmission characteristics of radio wave refraction plates installed adjacent to each other according to the embodiment.

[0050] 12, the radio wave refraction plate 14-1 and the radio wave refraction plate 14-2 are installed adjacent to each other so that the area included in the odd-order Fresnel zone is larger than the area included in the even-order Fresnel zone. The radio wave refraction plate 14-1 and the radio wave refraction plate 14-2 may be installed in the same odd-order Fresnel zone or in different odd-order Fresnel zones.

[0051] The radio wave refraction plate 14-1 includes an element 22A, an element 24A, an element 26A, etc. The radio wave refraction plate 14-2 includes an element 22B, an element 24B, etc. In the example shown in Fig. 12, the elements 22A, 24A, 26A, etc., and the elements 22B, 24B, etc. are installed adjacent to each other.

[0052] In the graph of Figure 12, the horizontal axis indicates the installation position of radio wave refraction plate 14, and the vertical axis indicates the amount of phase change [degrees]. Point P1 indicates the installation position and amount of phase change of element 22A. Point P2 indicates the installation position and amount of phase change of element 24A. Point P3 indicates the installation position and amount of phase change of element 26A. Point P4 indicates the installation position and amount of phase change of element 22B. Point P5 indicates the installation position and amount of phase change of element 24B.

[0053] 12, in this embodiment, the radio wave refraction plate 14-1 and the radio wave refraction plate 14-2 are installed so that the points P1 to P5 are on a straight line 61. This allows the radio wave refraction plate 14-1 and the radio wave refraction plate 14-2 to increase the received power of the refracted radio waves, thereby further improving the characteristics.

[0054] 13, the radio wave refraction plate 14-1 is installed so that the area included in the odd-order Fresnel zone is larger than the area included in the even-order Fresnel zone. The radio wave refraction plate 14-3 is installed so that the area included in the even-order Fresnel zone is larger than the area included in the odd-order Fresnel zone. The radio wave refraction plate 14-1 and the radio wave refraction plate 14-3 are installed adjacent to each other.

[0055] In the graph of Figure 13, the horizontal axis indicates the installation position of radio wave refraction plate 14, and the vertical axis indicates the amount of phase change [degrees]. Point P1 indicates the installation position and amount of phase change of element 22A. Point P2 indicates the installation position and amount of phase change of element 24A. Point P3 indicates the installation position and amount of phase change of element 26A. Point P11 indicates the installation position and amount of phase change of element 22C. Point P12 indicates the installation position and amount of phase change of element 24C.

[0056] 13, in this embodiment, the radio wave refraction plate 14-1 is installed so that points P1 to P3 are on a straight line 61, and the radio wave refraction plate 14-3 is installed so that points P11 and P12 are off the straight line 61. In other words, a radio wave refraction plate whose area included in the even-order Fresnel zone is larger than the area included in the odd-order Fresnel zone is installed so as to be off the straight line 61.

[0057] 13, the radio wave refraction plate 14-3 is installed so that points P11 and P12 are on a straight line 62. In other words, the radio wave refraction plate 14-3 is installed so that the amount of phase change deviates from that of the radio wave refraction plate 14-1. Since the even-order Fresnel zone is an area where radio waves weaken each other, by installing the radio wave refraction plate 14-3 so that it deviates from the straight line 61, it is possible to increase the received power of the refracted radio waves and further improve the characteristics.

[0058] The arrow between the lines 61 and 62 indicates the difference in the amount of phase change between the lines 61 and 62. The characteristics can be further improved by setting the difference in the amount of phase change between the lines 61 and 62 to, for example, 180°. Note that the difference in the amount of phase change between the lines 61 and 62 is not limited to 180°.

[0059] 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. [Explanation of symbols]

[0060] 1. Communication Systems 10 base station 12 terminals 14 Radio wave refraction plate 16 plane 20 Substrate 22, 24, 26, 28 elements 30-1,30-2 Radio wave reflector 50 First Fresnel Zone 52 Second Fresnel Zone 54 Third Fresnel Zone 56 4th Fresnel Zone

Claims

1. a base station configured to transmit and receive radio waves; a terminal configured to transmit and receive the radio waves to and from the base station; a plurality of radio wave refraction plates installed on the same plane between the base station and the terminal, configured to refract the radio waves transmitted from the base station toward the terminal when the radio waves pass through the radio wave refraction plates and output the refracted radio waves; Including, each of the plurality of radio wave refraction plates is installed in an area defined on an installation plane that passes through the geometric centers of the plurality of radio wave refraction plates and is perpendicular to a line connecting the antenna of the base station and the antenna of the terminal, based on a first linear distance between the antenna of the base station and the geometric center of each of the plurality of radio wave refraction plates and a second linear distance between the antenna of the terminal and the geometric center of each of the plurality of radio wave refraction plates; the area defined based on the first linear distance and the second linear distance includes an odd-order Fresnel zone and an even-order Fresnel zone, each of the plurality of radio wave refraction plates is installed such that, when an area of ​​each of the plurality of radio wave refraction plates projected onto the installation plane is considered, an area included in the odd-order Fresnel zone is larger than an area included in the even-order Fresnel zone; Communication system.

2. A base station configured to transmit and receive radio waves; a terminal configured to transmit and receive the radio waves to and from the base station; a plurality of radio wave refraction plates installed on the same plane between the base station and the terminal, configured to refract the radio waves transmitted from the base station toward the terminal when the radio waves pass through the radio wave refraction plates and output the refracted radio waves; Including, When the distance between adjacent radio wave refraction plates is s and the refraction angle of the radio waves is θ, the deviation in the thickness direction between adjacent radio wave refraction plates is s / tanθ or less. Communication system.

3. A base station configured to transmit and receive radio waves; a terminal configured to transmit and receive the radio waves to and from the base station; a plurality of radio wave refraction plates installed on the same plane between the base station and the terminal, configured to refract the radio waves transmitted from the base station toward the terminal when the radio waves pass through the radio wave refraction plates and output the refracted radio waves; Including, When the sum of the maximum dimensions of the plurality of radio wave refraction plates is L sum and the wavelength of the radio wave is λ, the distance between the antenna of the terminal and the geometric center of each of the plurality of radio wave refraction plates is greater than 0.62 × (L sum 3 / λ); Communication system.

4. A base station configured to transmit and receive radio waves; a terminal configured to transmit and receive the radio waves to and from the base station; a plurality of radio wave refraction plates installed on the same plane between the base station and the terminal, configured to refract the radio waves transmitted from the base station toward the terminal when the radio waves pass through the radio wave refraction plates and output the refracted radio waves; Including, the plurality of radio wave refraction plates are arranged so that when the coordinates of each of the plurality of unit structures included in the plurality of radio wave refraction plates are plotted on a graph where the horizontal axis indicates position and the vertical axis indicates transmission phase, the coordinates are on a straight line. Communication system.

5. each of the plurality of radio wave refraction plates is installed in an area defined on an installation plane that passes through the geometric centers of the plurality of radio wave refraction plates and is perpendicular to a line connecting the antenna of the base station and the antenna of the terminal, based on a first linear distance between the antenna of the base station and the geometric center of each of the plurality of radio wave refraction plates, and a second linear distance between the antenna of the terminal and the geometric center of each of the plurality of radio wave refraction plates; A communication system according to any one of claims 2 to 4.

6. The first linear distance is d １ , the second linear distance is d ２ Then, on the installation plane, consider a circle having a geometric center C as its center and a radius defined by the following formula (1): [Equation 1] In the formula (1), n ​​is a natural number, λ is the wavelength of the radio wave, The radio wave refraction plate has a radius R ｎ－１ From radius R ｎ When the annular portion in the range of is defined as the n-th Fresnel zone, the areas of the plurality of radio wave refraction plates included in the odd-order Fresnel zone are set larger than the areas of the plurality of radio wave refraction plates included in the even-order Fresnel zone. The communication system according to claim 5 .

7. When the coordinates of each of the plurality of unit structures included in the plurality of radio wave refraction plates are plotted on a graph where the horizontal axis indicates position and the vertical axis indicates transmission phase, among the plurality of radio wave refraction plates, those whose area included in the odd-order Fresnel zone is larger than the area included in the even-order Fresnel zone are placed on a straight line, and those whose area included in the even-order Fresnel zone is larger than the area included in the odd-order Fresnel zone are placed off the straight line. The communication system of claim 1 .

8. When the area included in the even-numbered Fresnel zone is larger than the area included in the odd-numbered Fresnel zone, the Fresnel zone is installed so that the phase change amount is shifted by 180° from the straight line. The communication system according to claim 7.

9. A radio wave refraction plate, which is installed in plurality on the same plane between a transmitting point and a receiving point, and is configured to refract the radio wave transmitted from the transmitting point toward the receiving point when the radio wave passes through the plate, and emit the refracted radio wave, In an installation plane that passes through the geometric centers of the plurality of radio wave refraction plates and is perpendicular to a line connecting the transmission point and the reception point, the radio wave refraction plates are installed in an area defined based on a first linear distance between the transmission point and the geometric center of each of the plurality of radio wave refraction plates and a second linear distance between the reception point and the geometric center of each of the plurality of radio wave refraction plates, the area defined based on the first linear distance and the second linear distance includes an odd-order Fresnel zone and an even-order Fresnel zone, When the area of ​​each of the plurality of radio wave refraction plates projected onto the installation plane is considered, the area included in the odd-order Fresnel zone is set larger than the area included in the even-order Fresnel zone. Radio wave refraction plate.

10. A radio wave refraction plate, which is installed in plurality on the same plane and is configured to refract radio waves at a predetermined refraction angle when the radio waves pass through the plate, When the distance between adjacent radio wave refraction plates is s and the refraction angle of the radio waves is θ, the deviation in the thickness direction between adjacent radio wave refraction plates is s / tanθ or less. Radio wave refraction plate.

11. A radio wave refraction plate, which is installed in plurality on the same plane and is configured to refract radio waves at a predetermined refraction angle when the radio waves pass through the plate, When the sum of the maximum dimensions of the plurality of radio wave refraction plates is L sum and the wavelength of the radio wave is λ, the distance between the receiving point and the geometric center of each of the plurality of radio wave refraction plates is greater than 0.62 × (L sum 3 / λ); Radio wave refraction plate.

12. A radio wave refraction plate, which is installed in plurality on the same plane and is configured to refract radio waves at a predetermined refraction angle when the radio waves pass through the plate, the plurality of unit structures are arranged so that when the coordinates of each of the plurality of unit structures included in the plurality of radio wave refraction plates are plotted on a graph where the horizontal axis indicates position and the vertical axis indicates transmission phase, the coordinates are on a straight line. Radio wave refraction plate.

13. In an installation plane that passes through the geometric centers of the plurality of radio wave refraction plates and is perpendicular to a line connecting a transmission point and a reception point, the plurality of radio wave refraction plates are installed in an area defined based on a first linear distance between the transmission point and the geometric center of each of the plurality of radio wave refraction plates and a second linear distance between the reception point and the geometric center of each of the plurality of radio wave refraction plates.

13. A radio wave refraction plate according to any one of claims 10 to 12.

14. The first linear distance is d １ , the second linear distance is d ２ Then, on the installation plane, consider a circle having a geometric center C as its center and a radius defined by the following formula (1): [Equation 2] In the formula (1), n ​​is a natural number, λ is the wavelength of the radio wave, Radius R ｎ－１ From radius R ｎ When the annular portion in the range of is defined as the n-th Fresnel zone, the areas of the plurality of radio wave refraction plates included in the odd-order Fresnel zone are set larger than the areas of the plurality of radio wave refraction plates included in the even-order Fresnel zone.

14. The radio wave refraction plate according to claim 13.

15. When the coordinates of each of the plurality of unit structures included in the plurality of radio wave refraction plates are plotted on a graph where the horizontal axis indicates position and the vertical axis indicates transmission phase, among the plurality of radio wave refraction plates, those whose area included in the odd-order Fresnel zone is larger than the area included in the even-order Fresnel zone are placed on a straight line, and those whose area included in the even-order Fresnel zone is larger than the area included in the odd-order Fresnel zone are placed off the straight line.

10. The radio wave refraction plate according to claim 9.

16. When the area included in the even-numbered Fresnel zone is larger than the area included in the odd-numbered Fresnel zone, the Fresnel zone is installed so that the phase change amount is shifted by 180° from the straight line.

16. The radio wave refraction plate according to claim 15.

17. Calculating a geometric center of the center points of the multiple radio wave refraction plates that are installed; setting a plane that passes through the geometric center and is perpendicular to a straight line that connects a transmission point that transmits radio waves to the plurality of radio wave refraction plates and a reception point that receives the radio waves refracted by the radio wave refraction plates; projecting the plurality of wave refraction plates onto the plane; calculating installation positions of the plurality of radio wave refraction plates so that the areas of the plurality of radio wave refraction plates included in odd-order Fresnel zones on the plane are larger than the areas of the plurality of radio wave refraction plates included in even-order Fresnel zones; A method for calculating the installation position of a radio wave refraction plate, including:

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