JP2021057722A - Radio wave transmission plate and radio wave transmission system - Google Patents

Abstract

To provide a radio wave transmitting plate and a radio wave transmitting system that control an emission direction while selectively transmitting an incident electromagnetic wave.SOLUTION: A radio wave transmitting plate that transmits radio waves of a specific frequency 10 includes a plurality of first elements 20 periodically arranged in a first direction on a first plane and a second direction orthogonal to the first direction, and a plurality of first unit cells 30 which are arranged in the first direction and the second direction on a second plane parallel to the first plane corresponding to the plurality of first elements 20, and each has a specific dielectric constant. At least one of the shapes of the plurality of first elements 20 and the dielectric constants of the plurality of first unit cells 30 is formed so as to change in the first direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to a radio wave transmitting plate and a radio wave transmitting system.

Conventionally, there is known a metamaterial technique for controlling the propagation characteristics of electromagnetic waves by periodically arranging conductor patterns having a specific structure. For example, there is known a technique for controlling the transmission characteristics and reflection characteristics of an incident electromagnetic wave by periodically arranging conductor patterns smaller than the wavelength of the incident electromagnetic wave in a two-dimensional manner (for example,). See Patent Document 1).

Japanese Unexamined Patent Publication No. 2003-60430

The metamaterial technology can realize, for example, a frequency selection function that reflects unnecessary radio waves while transmitting radio waves to be propagated. Such a technique is expected to be able to control not only the transmission characteristics and reflection characteristics of an incident electromagnetic wave but also the propagation direction of radio waves so that radio waves can be transmitted and received more efficiently.

Therefore, the present invention has been made in view of these points, and an object of the present invention is to enable control of the emission direction while selectively transmitting incident electromagnetic waves.

In the first aspect of the present invention, it is a radio wave transmitting plate that transmits radio waves of a specific frequency, and is periodically arranged in a first direction on a first plane and a second direction orthogonal to the first direction. The plurality of first elements and the plurality of the first elements are arranged in the first direction and the second direction on the second plane parallel to the first plane, and have a specific dielectric constant. The shape of the first element and the dielectric constants of the first unit cells are formed so as to change in the first direction. Provide a radio wave transmission plate.

The plurality of first elements may be formed as at least a part of a frequency selection film that transmits radio waves of a specific frequency input toward the first plane. The plurality of first unit cells may be formed so that at least one of the cell size, shape, and material is different in the first direction.

The plurality of first unit cells may be formed as a part of a device having a variable dielectric constant according to an input control signal.

The plurality of first elements are formed as at least a part of a frequency selection film that transmits radio waves of a specific frequency input toward the first plane, and the size and / or area of the elements in the first direction. May increase or decrease, and the propagation direction of radio waves transmitted through the plurality of first elements may be changed according to changes in the size and / or area of the element.

In the second aspect of the present invention, in a radio wave transmitting plate that transmits radio waves of a specific frequency, in a first direction on a first plane into which radio waves are input and in a second direction orthogonal to the first direction. A plurality of periodically arranged first elements and a plurality of the first elements are provided in the first direction and the second direction on a second plane parallel to the first plane. A plurality of first unit cells each having a specific dielectric constant and radio waves transmitted through the plurality of first unit cells are input, and the first direction and the said on a third plane parallel to the first plane. The first direction and the second direction on the fourth plane parallel to the third plane corresponding to the plurality of second elements periodically arranged in the second direction and the plurality of the second elements. A plurality of second unit cells each having a specific dielectric constant, the shape of the plurality of the first elements, the dielectric constants of the plurality of the first unit cells, and the plurality of the second units. At least one of the shape of the element, the dielectric constants of the plurality of second unit cells, and the distance between each of the plurality of first unit cells and each of the corresponding plurality of second elements is. Provided is a radio wave transmitting plate formed so as to change in the first direction.

The plurality of first elements may be formed as at least a part of a frequency selection film that transmits radio waves of a specific frequency input toward the first plane.

In the third aspect of the present invention, a plurality of the radio wave transmitting plates of the first aspect are provided, and each of the plurality of radio wave transmitting plates is stacked by a specific distance. ..

In the fourth aspect of the present invention, a radio wave input unit in which a first radio wave of a specific frequency propagates from the outside and communicates with the first space, and first to third radio wave input units provided in the radio wave input unit. The radio wave transmitting plate according to any one of the embodiments is provided, and the radio wave transmitting plate propagates the propagation direction of the first radio wave input from the radio wave input unit to a specific region in the first space. Provide a radio wave transmission system that changes direction.

In the fifth aspect of the present invention, the first radio wave generator that generates the first radio wave of a specific frequency and the external first space are communicated, and the first radio wave is propagated to the first space. A radio wave output unit and the radio wave transmission plate of any one of the first to third aspects provided in the radio wave output unit are provided, and the radio wave transmission plate is generated by the first radio wave generator. Provided is a radio wave transmission system that changes the propagation direction of the first radio wave in a direction of propagating to a specific region in the first space.

According to the present invention, there is an effect that the emission direction can be controlled while selectively transmitting the incident electromagnetic wave.

A first configuration example of the radio wave transmitting plate 10 according to the present embodiment is shown. An example of the AA'cross-sectional view of the radio wave transmitting plate 10 of the first configuration example shown in FIG. 1 is shown. A second configuration example of the radio wave transmitting plate 10 according to the present embodiment is shown. A third configuration example of the radio wave transmitting plate 10 according to the present embodiment is shown. An example of the equivalent circuit of the radio wave transmission plate 10 of the third configuration example is shown. A first configuration example of the radio wave transmission system 100 using the radio wave transmission plate 10 according to the present embodiment is shown. A second configuration example of the radio wave transmission system 100 using the radio wave transmission plate 10 according to the present embodiment is shown.

<First configuration example of the radio wave transmitting plate 10>
FIG. 1 shows a first configuration example of the radio wave transmitting plate 10 according to the present embodiment. In the present embodiment, the radio wave incident on the radio wave transmitting plate 10 will be described as an example of the electromagnetic wave, but the technical scope of the present invention is not limited to the radio wave. FIG. 2 shows an example of a cross-sectional view taken along the line AA'of the radio wave transmitting plate 10 of the first configuration example shown in FIG. In FIGS. 1 and 2, three axes orthogonal to each other are shown as an X-axis, a Y-axis, and a Z-axis.

The radio wave transmitting plate 10 transmits radio waves of a specific frequency. The specific frequency is, for example, a predetermined frequency. Further, the radio wave transmitting plate 10 reflects or absorbs radio waves having a frequency other than a specific frequency. For example, the radio wave transmission plate 10 transmits radio waves in the communication band used in wireless communication. Further, the radio wave transmitting plate 10 emits radio waves transmitted in a specific emitting direction. The specific emission direction is, for example, a predetermined emission direction. 1 and 2 show an example in which the radio wave transmitting plate 10 is arranged substantially parallel to the XY plane, and the direction of the radio wave incident on the radio wave transmitting plate 10 is substantially parallel to the Z axis. The radio wave transmitting plate 10 includes a first element 20, a first unit cell 30, and a substrate 40.

The plurality of first elements 20 have conductivity and are periodically arranged in the first direction on the first plane and in the second direction orthogonal to the first direction. In FIGS. 1 and 2, the first plane is a plane substantially parallel to the XY plane, the first direction is a direction substantially parallel to the X axis, and the second direction is a direction substantially parallel to the Y axis. The plurality of first elements 20 have substantially the same shape, for example, and are arranged at predetermined intervals in the first direction and the second direction. As an example, the plurality of first elements 20 are arranged at equal intervals in the first direction and the second direction.

The plurality of first elements 20 are formed as at least a part of a frequency selection film that transmits radio waves of a predetermined frequency input toward the first plane. The shape of the first element 20 has sides, diameters, and the like having a length similar to, for example, 1/2, 1/3, ..., Etc. of the wavelength of the radio wave to be reflected or absorbed.

The specific shape of the first element 20 is, for example, a polygon including a triangle, a square, a rectangle, a trapezoid, and the like, a circle, an ellipse, a linear shape, a cross shape, and the like. Further, the shape of the first element 20 may have a notch, an opening, or the like. It is desirable that the first element 20 is made of metal or the like. Since the shape and material of the first element 20 are known as FSS (Freequency Selective Sheet / Surface) in metamaterial technology, detailed description thereof will be omitted here. The plurality of first elements 20 may be further covered with a protective film such as a dielectric material.

The plurality of first unit cells 30 are arranged in the first direction and the second direction on the second plane parallel to the first plane, corresponding to the plurality of first elements 20. For example, the corresponding first element 20 is formed on the upper surface of each first unit cell 30. In this case, the upper surfaces of the plurality of first unit cells 30 are formed as the first plane. Then, the radio wave transmitted through the first element 20 is input to the corresponding first unit cell 30. A dielectric film or the like may be formed between the plurality of first unit cells 30 and the plurality of first elements 20.

Each of the plurality of first unit cells 30 has a specific dielectric constant, and transmits radio waves transmitted through the plurality of first elements 20. The specific permittivity is, for example, a predetermined permittivity. The permittivity of the plurality of first unit cells 30 is formed so as to change in the first direction. The plurality of first unit cells 30 are formed so that at least one of the cell size, shape, and material is different in the first direction. For example, the permittivity of the plurality of first unit cells 30 is formed so as to increase or decrease at a constant rate. Further, the first unit cell 30 is formed so that the dielectric constant is substantially constant in the second direction.

Adjacent first unit cells 30 are formed separately, for example. The first unit cell 30 may be formed with a constant dielectric constant in the second direction and integrally formed in the second direction. Further, the adjacent first unit cells 30 may be formed so as to be in contact with each other. Instead, the plurality of first unit cells 30 may be integrally formed. In this case, for example, the plurality of first unit cells 30 are formed as a dielectric film having a distribution in which the permittivity changes in the first direction.

The substrate 40 is provided with a plurality of first elements 20 and a plurality of first unit cells 30. The substrate 40 is provided with, for example, a plurality of first unit cells 30 on the upper surface thereof. In this case, the upper surface of the substrate 40 is the second plane. Further, another dielectric film or the like may be formed between the substrate 40 and the plurality of first unit cells 30. For example, if there is a gap between the adjacent first unit cells 30, or if there is a gap between the plurality of first unit cells 30 and the substrate 40, at least a part of the gap is filled. As described above, it is desirable that another dielectric film or the like is formed.

The substrate 40 is made of a material that transmits radio waves that have passed through the plurality of first unit cells 30. The substrate 40 is, for example, a glass substrate. When the plurality of first unit cells 30 are formed as a dielectric film, the substrate 40 may be omitted.

The radio wave transmitting plate 10 according to the above embodiment emits radio waves transmitted from a predetermined emission direction according to the respective dielectric constants of the first unit cell 30. Here, consider the case where a radio wave having a frequency f is incident on a substance. The phase velocity v _{p in a substance can be expressed as v p} = f · λ = c / n using the speed of light c in vacuum and the refractive index n of the substance, and _{the refractive index n is (ε r} · μ. _r ) Equal to ^1/2. Ε _r is the permittivity of the substance, and μ _r is the magnetic permeability of the substance. Therefore, the phase velocity of the radio wave having the frequency f passing through the dielectric medium _{becomes slower as the permittivity ε r} increases, and the wavelength λ is shortened.

FIG. 2 shows an example in which the dielectric constants ε _rm of the plurality of first unit cells 30 are formed so as to increase at a constant rate in the first direction. In this case, the refractive indexes of the plurality of first unit cells 30 also increase at a constant rate in the first direction, and the phase velocity decreases. Therefore, the phase of the radio wave transmitted through the plurality of first unit cells 30 changes at a constant rate for each first unit cell 30 in the first direction. Here, let φ be the amount of change in the phase of the radio wave for each first unit cell 30.

For example, assuming that the phase rotation amount of the radio wave passing through the first first unit cell 30 is φ _{0 , the rotation amount φ m} of the phase of the radio wave passing through the mth first unit cell 30 is expressed by the following equation. Is done.
(Number 1)
φ _m = φ ₀ + (m-1) φ

Since the equivalent circuit of the combination of one first element 20 and one first unit cell 30 _{is a parallel circuit of the impedance component Z p} corresponding to the LC component and the impedance component δ corresponding to the dielectric constant. The impedance Z seen from the incident direction of the radio wave is _{expressed by the sum of these Z p} + δ. _{For example, the impedance Z m} of the set of the m-th first element 20 and the first unit cell 30 is expressed by the following equation, and the phase of the radio wave incident by the _{impedance Z m} is rotated by _{the rotation amount φ m of the following equation.}
(Number 2)
Z _m = Z _mp + δ _m
φ _m = arg (Z _m )

In this way, the radio waves that have passed through the plurality of first unit cells 30 and whose phases have rotated are transmitted through the substrate 40 and output while maintaining the phase difference between the radio waves that have passed through the different first unit cells 30. Will be done. In the case of the example of FIG. 2, among the radio waves transmitted through the radio wave transmitting plate 10, the radio wave closer to the first first unit cell 30 has a faster phase advance, and the radio wave farther from the first first unit cell 30 is separated. The slower the phase advance.

As described above, the radio wave transmitted through the radio wave transmitting plate 10 has a constant ratio of phase difference in the first direction in response to the change in the dielectric constant of the plurality of first unit cells 30. In other words, the radio wave transmitted through the radio wave transmitting plate 10 is output with the equiphase plane tilted by θ with respect to the XY plane according to the change in the dielectric constant of the plurality of first unit cells 30 in the first direction. .. This means that the radio waves transmitted through the radio wave transmitting plate 10 propagated in a direction different from the input direction by θ. In the case of the example of FIG. 2, the radio wave transmitted through the radio wave transmitting plate 10 is output tilted toward the first direction.

Here, assuming that the propagation direction of the radio wave input to the radio wave transmitting plate 10 is the −Z direction and the angle between the propagation direction of the radio wave transmitted through the radio wave transmitting plate 10 and the −Z direction is the output angle θ, the output angle θ is as follows. It is shown by the formula. Here, d is the distance between adjacent first unit cells 30.
(Number 3)
θ = asin (φ / d)

As described above, the radio wave transmitting plate 10 according to the present embodiment transmits radio waves having a predetermined frequency among the input radio waves, and the transmitted radio waves are based on the dielectric constants of the plurality of first unit cells 30. Output in the direction. That is, the radio wave transmitting plate 10 can control the transmission characteristic and the reflection characteristic of the incident radio wave and the propagation direction of the radio wave with a simple configuration using the plurality of first elements 20 and the plurality of first unit cells 30.

In other words, if the distance between the centers of the adjacent first unit cells 30 is represented by a wavelength ratio and is p, the phase of the radio wave input for each first unit cell 30 is ^{delayed by φ = p 2} sin θ ² and output. Then, the output angle of the transmitted radio wave can be set to θ. In this case, for example, m-th of the first unit cell 30 may be designed radio waves incident to rotate by the rotation amount phi _m the following equation.
(Number 4)
φ _m = arg (Z _m ) = (mp) ² sin ² θ

Although the radio wave transmitting plate 10 includes a plurality of first unit cells 30 whose dielectric constants are changed in the first direction in FIGS. 1 and 2, the present invention is not limited thereto. The plurality of first unit cells 30 may change the dielectric constant in the second direction, or may change the dielectric constant in both the first direction and the second direction.

Further, in FIGS. 1 and 2, an example in which each of the first unit cells 30 has a predetermined dielectric constant has been described, but the present invention is not limited thereto. For example, the plurality of first unit cells 30 may be formed as a part of a device having a variable dielectric constant according to an input control signal. For example, the plurality of first unit cells 30 are at least a part of the liquid crystal panel. In this case, one pixel whose dielectric constant of the liquid crystal panel can be adjusted may be formed as one first unit cell 30, and instead, a plurality of pixels are formed as one first unit cell 30. May be.

The liquid crystal panel can adjust the phase of the radio wave transmitted through the pixel by applying a voltage of about several V to each pixel, for example. Therefore, by supplying control signals that change the dielectric constant in the first direction and / or the second direction to the plurality of first unit cells 30, radio waves are transmitted from the radio wave transmitting plate 10 in the direction corresponding to the control signals. Can be output. Further, by switching the control signal in time, the direction of the radio wave output by the radio wave transmitting plate 10 can be switched.

In the radio wave transmitting plate 10 according to the present embodiment, the example in which the radio wave is incident substantially perpendicular to the first plane has been described, but the present invention is not limited to this. Radio waves may be incident on the radio _{wave transmitting plate 10 in} a direction having a specific angle θ in with respect to the vertical direction. In this case, the phase of the input radio wave is rotated by _{p × cos (θ in) for each unit cell.} In other words, when radio waves are transmitted from the radio wave transmitting plate 10 _{in a direction having a specific angle θ out} with respect to the vertical direction, the phase of each unit cell is only p × cos (θ _out ) −p × cos (θ _in ). The dielectric constant of the unit and the like may be designed so as to rotate.

Further, the radio wave may be transmitted from the radio wave transmitting plate 10 in a direction having a _{specific azimuth angle ψ out} and / or elevation angle θ _out. In this case, assuming that the unit cell spacing in the X direction is p _X and the unit cell spacing in the Y direction is p _Y , the phase of each unit cell is p _X × sin (θ _out ) × cos (θ _out ) + p _Y × sin ( The permittivity of the unit and the like may be designed so as to rotate by ψ _out ) × sin (ψ _out).

The above-described example of controlling the direction of the radio wave output by the radio wave transmitting plate 10 by changing the dielectric constants of the plurality of first unit cells 30 of the radio wave transmitting plate 10 according to the present embodiment has been described. There is no limitation. Alternatively or in addition to this, the direction of the radio wave output by the radio wave transmitting plate 10 may be controlled by changing the shape of the plurality of first elements provided on the radio wave transmitting plate 10. Good. Such a radio wave transmitting plate 10 will be described below.

<Second configuration example of the radio wave transmitting plate 10>
FIG. 3 shows a second configuration example of the radio wave transmitting plate 10 according to the present embodiment. In the radio wave transmitting plate 10 of the second configuration example, those substantially the same as the operation of the radio wave transmitting plate 10 according to the present embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. The radio wave transmitting plate 10 of the second configuration example includes a plurality of first elements 20 formed so as to change in shape in the first direction. Further, the radio wave transmitting plate 10 of the second configuration example includes a plurality of first unit cells 30 described in the radio wave transmitting plate 10 of the first configuration example.

As described with reference to FIGS. 1 and 2, the plurality of first elements 20 are formed as at least a part of a frequency selection film that transmits radio waves of a predetermined frequency input toward the first plane. The plurality of first elements 20 are formed so that the size and / or area of the element increases or decreases in the first direction, and the plurality of first elements 20 are formed according to changes in the size and / or area of the element. Change the propagation direction of the radio wave transmitted through.

FIG. 3 shows an example in which the sizes of the plurality of first elements 20 are provided so as to increase at a constant rate in the first direction. _{As a result, the impedance component Z mp} corresponding to the capacitance component of Eq. (Equation 2) increases at a constant rate in the first direction, so that the overall impedance Z _m also increases in the same manner as in the example of the change in permittivity in FIG. , Increases at a constant rate in the first direction. Therefore, the radio wave transmitting plate 10 of the second configuration example shown in FIG. 3 transmits a radio wave having a predetermined frequency input perpendicularly to the first plane, and bends the transmitted radio wave to the first direction side and outputs the radio wave. ..

As described above, in the radio wave transmitting plate 10 according to the present embodiment, the radio waves are formed by forming the shapes of the plurality of first elements 20 or the dielectric constants of the plurality of first unit cells 30 so as to change in the first direction. The propagation direction of the radio wave input to the transmission plate 10 can be changed and output. In addition, both the shape of the plurality of first elements 20 and the dielectric constants of the plurality of first unit cells 30 may be formed so as to change with respect to a predetermined direction on the first plane.

For example, in the radio wave transmitting plate 10, the shapes of the plurality of first elements 20 and the dielectric constants of the plurality of first unit cells 30 are formed so as to change in the same direction of the radio wave transmitting plate 10. In this case, for example, it is desirable that the first element 20 is formed so that the shape of the first element 20 increases and the dielectric constant of the first unit cell 30 increases in the same direction. As a result, the range in which the radio wave transmitting plate 10 can change the propagation direction of the radio wave can be expanded.

Further, in the radio wave transmitting plate 10, the direction of change in the shape of the plurality of first elements 20 and the direction of change in the dielectric constant of the plurality of first unit cells 30 may be formed in different directions. In this case, the radio wave transmitting plate 10 can change the propagation direction of the radio wave to the direction in which the shape change direction of the first element 20 and the change direction of the permittivity of the first unit cell 30 are combined. The degree of freedom in designing the transmission plate 10 can be improved.

In the radio wave transmitting plate 10 according to the present embodiment, the example in which the layer formed by the plurality of first elements 20 and the layer formed by the plurality of first unit cells 30 are formed one layer on the substrate 40 has been described. , Not limited to this. The radio wave transmitting plate 10 may be provided with a plurality of layers at least one of a layer formed by the plurality of first elements 20 and a layer formed by the plurality of first unit cells 30. An example of such a radio wave transmitting plate 10 will be described below.

<Third configuration example of the radio wave transmitting plate 10>
FIG. 4 shows a third configuration example of the radio wave transmitting plate 10 according to the present embodiment. FIG. 4 is an example of a cross-sectional view of the radio wave transmitting plate 10 of the third configuration example, which corresponds to the cross-sectional view of the radio wave transmitting plate 10 of the first configuration example shown in FIG. In the radio wave transmitting plate 10 of the third configuration example, those substantially the same as the operation of the radio wave transmitting plate 10 according to the present embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. The radio wave transmitting plate 10 of the third configuration example further includes a plurality of second elements 50 and a plurality of second unit cells 60.

The plurality of first elements 20 have conductivity and are periodically arranged in the first direction on the first plane into which radio waves are input and in the second direction orthogonal to the first direction. The plurality of first unit cells 30 are provided in the first direction and the second direction on the second plane parallel to the first plane, corresponding to the plurality of first elements 20, and have a predetermined dielectric constant. Each has. Since the first element 20 and the first unit cell 30 have been described with reference to FIGS. 1 to 3, the description thereof will be omitted here.

Radio waves transmitted through the plurality of first unit cells 30 are input to the plurality of second elements 50. Like the plurality of first elements 20, the plurality of second elements 50 have conductivity and are periodically arranged in the first direction and the second direction on the third plane parallel to the first plane. .. The plurality of second elements 50 are formed of substantially the same material and shape as the plurality of first elements 20. The plurality of second elements 50 are formed, for example, in substantially the same shape as the corresponding first element 20. In this case, the first second element 50 in which the radio wave transmitted through the first first element 20 is input via the first unit cell 30 is defined as the element corresponding to the first first element 20.

The plurality of second unit cells 60 are provided in the first direction and the second direction on the fourth plane parallel to the third plane, corresponding to the plurality of second elements 50, and have a predetermined dielectric constant. Each has. The plurality of second unit cells 60 are formed of substantially the same material and shape as the plurality of first unit cells 30. For example, a corresponding second element 50 is formed on the upper surface of each second unit cell 60. In this case, the upper surfaces of the plurality of second unit cells 60 are formed as a third plane. Then, the radio wave transmitted through the second element 50 is input to the corresponding second unit cell 60. A dielectric film or the like may be formed between the plurality of second unit cells 60 and the plurality of second elements 50.

The substrate 40 is provided with, for example, a plurality of second unit cells 60 on the upper surface thereof. In this case, the upper surface of the substrate 40 is the fourth plane. Further, another dielectric film or the like may be formed between the substrate 40 and the plurality of second unit cells 60.

In the radio wave transmitting plate 10 of the above third configuration example, the shapes of the plurality of first elements 20, the dielectric constants of the plurality of first unit cells 30, the shapes of the plurality of second elements 50, and the plurality of second units. At least one of the permittivity of the cell 60 and the distance between each of the plurality of first unit cells 30 and each of the corresponding plurality of second elements 50 is formed so as to change in the first direction. ing.

It has already been shown in the figure that the propagation direction of the radio wave output from the radio wave transmitting plate 10 can be changed by arranging the plurality of first unit cells 30 so that the dielectric constants of the plurality of first unit cells 30 change in the first direction. 1 and FIG. 2 have been described. Similarly, by arranging the plurality of second unit cells 60 so that the dielectric constants of the plurality of second unit cells 60 change in the first direction, the propagation direction of the radio waves output from the radio wave transmitting plate 10 can be changed. Needless to say. The direction of change in the permittivity of the first unit cell 30 and the direction of change in the permittivity of the second unit cell 60 may be the same direction or different directions.

Further, by arranging the plurality of first elements 20 so that the size and / or area of the plurality of first elements 20 changes in the first direction, the propagation direction of the radio waves output from the radio wave transmitting plate 10 can be changed. , Already described in FIG. Similarly, by arranging the permittivity of the plurality of second elements 50 so that the permittivity of the plurality of second elements 50 changes in the first direction, the propagation direction of the radio wave output from the radio wave transmitting plate 10 can be changed. Needless to say. The direction of change in the size and / or area of the first element 20 and the direction of change in the size and / or area of the second element 50 may be the same direction or different directions.

When the distance between each of the plurality of first unit cells 30 and the corresponding plurality of second elements 50 is different, the coupling impedance between the first unit cell 30 and the corresponding second element 50 is different. In this case, the impedance of the combination of the first element 20 and the first unit cell 30 and the impedance of the combination of the second element 50 and the second unit cell 60 are combined by using the coupling coefficient k corresponding to the coupling impedance. It is possible to configure an equivalent circuit to make it. FIG. 5 shows an example of an equivalent circuit of the radio wave transmitting plate 10 of the third configuration example.

For example, the impedance of the set of the m-th first element 20 and the first unit cell 30 is Z _{1 m} , and the impedance of the set of the m-th second element 50 and the second unit cell 60 is Z _{2 m} . _{In this case, the impedance Z m} of the set of the m-th first element 20, the first unit cell 30, the second element 50, and the second unit cell 60 is expressed by the following equation. Further, the phase of the radio wave incident by the _{impedance Z m} is rotated by _{the rotation amount φ m of the following equation.}
(Number 5)
_{Z m = Z 1m + k m} Z 2m
φ _m = arg (Z _m )

Thus, for example, it is changed in each and corresponding to the coupling coefficient k _m and the distance between each changing of the plurality of second element 50 the first direction of the plurality of first unit cell 30 at a constant rate, The propagation direction of the radio wave output from the radio wave transmitting plate 10 can be changed. The value of the coupling coefficient k _m, not only the distance between the first unit cell 30 and the second element 50, by varying the area of overlap in the XY plane of the first unit cell 30 and the second element 50 Can also be adjusted. In this way, by changing the arrangement of each of the plurality of first unit cells 30 and the plurality of second elements 50 corresponding to each of the plurality of first unit cells 30, the propagation direction of the radio wave output from the radio wave transmitting plate 10 can be changed.

As described above, by stacking the conductive element and the dielectric unit cell in the Z direction, which is the stacking direction of the substrate 40, the range in which the propagation direction of the radio wave transmitted through the radio wave transmitting plate 10 can be changed is expanded. can do. In addition, the degree of freedom in designing the radio wave transmitting plate 10 can be improved. The number of elements and units to be laminated is not limited to two, and three or more may be laminated.

For example, assuming that the impedance of the pair of the m-th element j and the j unit cell of _{the jth layer is Z jm} and the coupling coefficient between the j-1 layer and the j layer is k _{(j-1) m} . The total impedance Z _m is expressed by the following equation.
(Number 6)
Z _m = Z _1m + k _1m Z _2m + k _2m Z _3m + ... + k _{(j-1) m} Z _jm + ...

When the radio wave transmitting plate 10 stacks a plurality of elements and a plurality of unit cells, different elements and different unit cells may be laminated, respectively, and instead, at least some elements or unit cells are omitted. It may be formed in the same manner. Further, the radio wave transmitting plate 10 may be provided with a plurality of the plurality of first elements 20 and the plurality of first unit cells 30 shown in FIGS. 1 to 3. For example, a plurality of individually prepared radio wave transmitting plates 10 may be stacked. In this case, the radio wave transmitting plates 10 may be stacked by a specific distance, or may be stacked so as to be offset in at least one of the first direction and the second direction. The specific distance is, for example, a predetermined distance.

The radio wave transmission plate 10 according to the present embodiment described above has described an example in which the propagation direction of the input radio wave is changed by an angle θ and output, but the present invention is not limited to this. The radio wave transmitting plate 10 may output the input radio wave by changing the propagation direction to a plurality of angles. For example, the first unit cell 30 from the first to the s _{changes the propagation direction of the input radio wave by an angle θ 1} , and the first unit cell 30 from the s th to the t changes the propagation direction of the input radio wave by an angle θ _2. You may only change. Further, the plurality of first unit cells 30 may change the input radio waves in different directions.

<First configuration example of radio wave transmission system 100>
FIG. 6 shows a first configuration example of the radio wave transmission system 100 using the radio wave transmission plate 10 according to the present embodiment. The radio wave transmission system 100 of the first configuration example simply supplies the first radio wave propagating from the outside to the receiving device 130 to be received. The receiving device 130 is, for example, a mobile terminal or the like. The radio wave transmission system 100 is provided in a building such as a building as an example. The radio wave transmission system 100 includes a radio wave transmission plate 10 and a radio wave input unit 110. The radio wave transmitting plate 10 is the radio wave transmitting plate 10 described with reference to FIGS. 1 to 4.

A first radio wave having a predetermined frequency propagates to the radio wave input unit 110 from the outside. The first radio wave is, for example, a communication signal of Wi-Fi (registered trademark), cellular or the like. The radio wave input unit 110 communicates with the first space 120. In FIG. 6, the first space 120 shows an example of being a room in a building. Further, the radio wave input unit 110 is, for example, a window. FIG. 6 shows an example in which a receiving device 130 existing in a part of a room of a building receives communication signals such as Wi-Fi and cellular propagating from a window.

The radio wave transmitting plate 10 is provided in such a radio wave input unit 110. The radio wave transmitting plate 10 is attached to, for example, at least a part of the glass portion of the window which is the radio wave input unit 110. The radio wave input unit 110 may be provided with a plurality of radio wave transmitting plates 10 having different propagation directions. Since the radio wave transmitting plate 10 functions as a frequency selection film that transmits radio waves of a predetermined frequency, the intensity level of a signal having a frequency different from that of the first radio wave to be received is reduced, and radio wave interference or the like occurs. Can be prevented.

Further, the radio wave transmitting plate 10 changes the propagation direction of the first radio wave input from the radio wave input unit 110 to the direction of propagating to a predetermined region in the first space 120. For the radio wave transmission plate 10, for example, a region including a flow line of the user holding the receiving device 130 is set as a predetermined region. As a result, even in an area different from the propagation direction of the first radio wave in the first space 120, the receiving device 130 is held or installed so that the receiving power can be prevented from being reduced and normal communication can be performed. Can be done. Therefore, in the first space 120, the area in which the receiving device 130 can communicate can be increased.

<Second configuration example of radio wave transmission system 100>
FIG. 7 shows a second configuration example of the radio wave transmission system 100 using the radio wave transmission plate 10 according to the present embodiment. The radio wave transmission system 100 of the second configuration example simply changes the propagation direction of the first radio wave propagating to the outside, and simply supplies the first radio wave to the receiving device 130. The radio wave transmission system 100 of the second configuration example is provided in a building such as a building as an example. The radio wave transmission system 100 of the second configuration example includes a radio wave transmission plate 10, a first radio wave generator 140, and a radio wave output unit 150. The radio wave transmitting plate 10 is the radio wave transmitting plate 10 described with reference to FIGS. 1 to 4.

The first radio wave generator 140 generates a first radio wave having a predetermined frequency. The first radio wave generator 140 is, for example, a base station device and a base station antenna. The first radio wave is, for example, a communication signal such as Wi-Fi or cellular. The first radio wave generator 140 outputs the first radio wave toward the radio wave output unit 150.

The radio wave output unit 150 communicates with the external first space 120 and propagates the first radio wave to the first space 120. In FIG. 7, the first space 120 shows an example in which the first radio wave should be supplied outside the building. Further, the radio wave output unit 150 is, for example, a window. FIG. 7 shows an example in which communication signals such as Wi-Fi and cellular are propagated from a first radio wave generator 140 in a part of a room of a building through a window which is a radio wave output unit 150.

The radio wave transmitting plate 10 is provided in such a radio wave output unit 150. The radio wave transmitting plate 10 is attached to, for example, the glass portion of the window which is the radio wave output unit 150. The radio wave output unit 150 may be provided with a plurality of radio wave transmission plates 10 having different propagation directions. Since the radio wave transmitting plate 10 functions as a frequency selection film that transmits radio waves of a predetermined frequency, the intensity level of a signal having a frequency different from that of the first radio wave to be transmitted is reduced, and unnecessary radio waves are sent to the outside. It can be prevented from propagating.

Further, the radio wave transmitting plate 10 changes the propagation direction of the first radio wave generated by the first radio wave generator 140 to a direction in which the first radio wave is propagated to a predetermined region in the first space 120. For the radio wave transmitting plate 10, for example, a region assigned to the first radio wave generator 140 is set as a predetermined region. Further, the radio wave transmitting plate 10 may have a region that is a coverage hole in a region different from the propagation direction of the first radio wave in the first space 120 as a predetermined region.

This makes it possible to increase the area in which the first radio wave from the base station can be received. Further, even if the base station, the base station antenna, and the like are not arranged in the vicinity of the radio wave output unit 150, it is possible to prevent an increase in the area where the first radio wave does not reach. Therefore, the area in which the base station and the base station antenna can be installed can be expanded, and the degree of freedom in design and the maintainability of the base station and the base station antenna can be improved.

In the above embodiment, the shape of the plurality of first elements 20 and the dielectric constants of the plurality of first unit cells 30 are formed so as to change in the first direction, so that the radio wave to be input is transmitted. An example of the radio wave transmitting plate 10 for controlling the transmission direction has been described. Here, the device formed by the metamaterial technique for controlling the propagation characteristics of electromagnetic waves can control not only the transmission characteristics but also the reflection characteristics in the same manner.

For example, by forming conductor patterns having a specific structure smaller than the wavelength of an incident electromagnetic wave by periodically arranging them in a two-dimensional manner, it can be formed as a reflector that reflects an input radio wave. .. Instead of this, by periodically arranging the dielectric pattern having a specific structure, it can be formed as a reflector that reflects the input radio wave. The specific structure is formed so as to reflect an electromagnetic wave having a specific frequency. Similar to the radio wave transmitting plate 10 described in the present embodiment, the reflector may be formed with a plurality of layers of a conductor pattern and / or a dielectric pattern, and a dielectric layer and a liquid crystal may be formed between the pattern layers. Etc. may be sandwiched and formed.

Such a radio wave reflecting plate is, for example, a radio wave transmitting plate that transmits radio waves of a specific frequency, and is periodically arranged in a first direction on a first plane and a second direction orthogonal to the first direction. A plurality of first elements and a plurality of elements which are arranged in the first direction and the second direction on the second plane parallel to the first plane and have specific dielectric constants corresponding to the plurality of first elements. The first unit cell is provided, and at least one of the shape of the plurality of first elements and the dielectric constant of the plurality of first unit cells is formed so as to change in the first direction.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes can be made within the scope of the gist thereof. is there. For example, all or a part of the device can be functionally or physically distributed / integrated in any unit. Also included in the embodiments of the present invention are new embodiments resulting from any combination of the plurality of embodiments. The effect of the new embodiment produced by the combination also has the effect of the original embodiment.

10 Radio wave transmission plate 20 1st element 30 1st unit cell 40 Board 50 2nd element 60 2nd unit cell 100 Radio wave transmission system 110 Radio wave input unit 120 1st space 130 Receiver 140 1st radio wave generator 150 Radio wave output unit

Claims (10)

A radio wave transmission plate that transmits radio waves of a specific frequency.
A plurality of first elements periodically arranged in the first direction on the first plane and the second direction orthogonal to the first direction, and
A plurality of first units arranged in the first direction and the second direction on a second plane parallel to the first plane and having a specific dielectric constant corresponding to the plurality of the first elements. Equipped with a cell,
A radio wave transmitting plate in which at least one of the shape of the plurality of first elements and the dielectric constants of the plurality of first unit cells is formed so as to change in the first direction. The radio wave transmission plate according to claim 1, wherein the plurality of first elements are formed as at least a part of a frequency selection film that transmits radio waves of a specific frequency input toward the first plane. The radio wave transmitting plate according to claim 1 or 2, wherein the plurality of first unit cells are formed so that at least one of the cell size, shape, and material is different in the first direction. The radio wave transmitting plate according to claim 1 or 2, wherein the plurality of first unit cells are formed as a part of a device having a variable dielectric constant according to an input control signal. The plurality of the first elements are
It is formed as at least a part of a frequency selection film that transmits radio waves of a specific frequency input toward the first plane.
It is formed so that the size and / or area of the element increases or decreases in the first direction, and the propagation direction of the radio wave transmitted through the plurality of first elements is changed according to the change in the size and / or area of the element. To do
The radio wave transmitting plate according to any one of claims 1 to 4. A radio wave transmission plate that transmits radio waves of a specific frequency.
A plurality of first elements arranged periodically in the first direction on the first plane into which radio waves are input and in the second direction orthogonal to the first direction, and
A plurality of first units provided in the first direction and the second direction on a second plane parallel to the first plane and having a specific dielectric constant corresponding to the plurality of the first elements. With the cell
A plurality of second elements to which radio waves transmitted through the plurality of first unit cells are input and periodically arranged in the first direction and the second direction on a third plane parallel to the first plane. When,
A plurality of second units provided in the first direction and the second direction on a fourth plane parallel to the third plane and having a specific dielectric constant corresponding to the plurality of the second elements. Equipped with a cell,
The shapes of the plurality of the first elements, the dielectric constants of the plurality of the first unit cells, the shapes of the plurality of the second elements, the dielectric constants of the plurality of the second unit cells, and the plurality of the first units. A radio wave transmitting plate in which at least one of the distances between each of the cells and each of the corresponding plurality of second elements is formed so as to change in the first direction. The radio wave transmitting plate according to claim 6, wherein the plurality of first elements are formed as at least a part of a frequency selection film that transmits radio waves of a specific frequency input toward the first plane. A plurality of the radio wave transmitting plates according to any one of claims 1 to 5 are provided.
Each of the plurality of radio wave transmitting plates is stacked at a specific distance.
Radio wave transmission plate. The radio wave input section where the first radio wave of a specific frequency propagates from the outside and leads to the first space,
The radio wave transmitting plate according to any one of claims 1 to 8 provided in the radio wave input unit is provided.
The radio wave transmitting plate changes the propagation direction of the first radio wave input from the radio wave input unit to a direction in which the first radio wave propagates to a specific region in the first space.
Radio transmission system. A first radio wave generator that generates the first radio wave of a specific frequency,
A radio wave output unit that communicates with an external first space and propagates the first radio wave to the first space,
The radio wave transmitting plate according to any one of claims 1 to 8 provided in the radio wave output unit is provided.
The radio wave transmitting plate changes the propagation direction of the first radio wave generated by the first radio wave generator to a direction in which the first radio wave propagates to a specific region in the first space.
Radio transmission system.

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