Metatwin and metasurface plates

Abstract

To provide a metatwin that can obtain a large phase change in a transmitted phase and a metasurface plate that can achieve from a small deflection angle to a large deflection angle of 60 degrees or more without increasing the overall volume and manufacturing cost.SOLUTION: A metatwin M1 is configured point-symmetrically on a center point O of the dielectric substrate 10 by forming on the top and bottom surfaces of a dielectric substrate 10 a first conductor pattern 11 and a second conductor pattern 12 of the same shape, which are half-cut from a basic conductor pattern. A number of metasurface plates are formed by periodically arranging the metatwins M1 in the x- and y-directions on the dielectric substrate. A first conductor pattern 11 is formed on the top surface of the dielectric substrate in a periodic array. A second conductor pattern 12 is formed on the underside of the dielectric substrate in a periodic array that corresponds to the first conductor pattern 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a metatwin that can obtain a large phase change in the transmitted phase, and a metasurface plate that can be placed in front of a radiation source to deflect the transmitted wave in a desired direction. [Background technology]

[0002] Electromagnetic communication devices with new functions that utilize the properties of metasurfaces are being developed both in Japan and overseas. Metasurfaces are artificial surfaces (hypersurfaces) with reflective properties that do not exist in nature, and have the ability to control the phase of incident electromagnetic waves. When metal elements that are small compared to the operating wavelength are periodically arranged on a planar plate, unusual electromagnetic field phenomena appear. Such planar plates are usually backed by a ground plane made of a metal plate. An artificial surface plate with this ground plane attached is called a reflective metasurface plate. In contrast, artificial surface thin plates without a ground plane are called transmission-type metasurface plates. It has been shown that placing a conventional transmission-type metasurface plate in front of an antenna can shape the radiation pattern of the transmitted wave.

[0003] FIG. 28 shows a configuration using a conventional transmission-type metasurface plate 110. As shown in FIG. 28, by placing the metasurface plate 110 in front of the patch antenna 130 (in the z direction), the incident wave from the patch antenna 130 passes through the metasurface plate 110 and becomes a transmitted wave with a predetermined radiation pattern. The patch antenna 130 is a rectangular conductor and is formed on the upper surface of an antenna substrate 131 made of a thin, rectangular parallelepiped dielectric plate. The antenna substrate 131 is placed on the upper surface of a rectangular ground plate 140, which functions as a ground plane for the patch antenna 130. The distance between the patch antenna 130 and the metasurface plate 110 is approximately ½λ, where λ is the free space wavelength of the operating frequency f.

[0004] Figure 29 shows the detailed configuration of the metasurface plate 110. The metasurface plate 110 is configured by forming a plurality of metal loop elements 112 periodically in the x and y directions on one surface of a dielectric substrate 120. The area where one loop element 112 is formed on the dielectric substrate 120 constitutes a unit element 111. The loop element 112 constituting the unit element 111 is shaped like a square, with the length of one side of the loop element 112 being St and the line width being Wt. All of the plurality of loop elements 112 formed on one surface of the dielectric substrate 120 have the same side length St and line width Wt, and are of the same shape.

[0005] Here, when analyzing a metasurface plate 110 in which loop elements 112 with a fixed length of one side St and only different line widths Wt are periodically arranged, it was found that as the line width Wt of the loop elements 112 becomes narrower, the transmission phase of the unit element 111 comprising the loop elements 112 becomes delayed. Based on this fact, it is possible to make the transmitted waves of the metasurface plate 110 into a radiation pattern directed in one, two, or four directions. Figure 30 shows the configuration of a conventional metasurface plate 110-1 that can create a radiation pattern that directs transmitted waves in a desired direction. The metasurface plate 110-1 shown in Figure 30 is configured by forming multiple metal loop elements 112a periodically in the x and y directions on one surface of a dielectric substrate 120. The length St of one side of each square-shaped loop element 112a is fixed, and the line width Wa is formed so that it gradually becomes wider in the x direction. In the y direction, the length St of one side of adjacent loop elements 112a and the line width Wa are fixed. In this case, the area where one loop element 112a is formed on the dielectric substrate 120 constitutes a unit element 111a.

[0006] When the metasurface plate 110 in FIG. 28 is replaced with the metasurface plate 110-1 shown in FIG. 30, the radiation pattern of the transmitted wave through the metasurface plate 110-1 is shown in FIG. 31. In this case, the distance between the patch antenna 130 and the metasurface plate 110-1 is approximately 1 / 2λ, where λ is the free-space wavelength of the operating frequency. As the line width Wa of the loop element 112a becomes narrower, the transmission phase shift of the unit element 111a including the loop element 112a becomes more delayed. Therefore, the transmission phase shift of the transmitted wave through the metasurface plate 110-1 becomes increasingly delayed in the -x direction. In other words, the transmitted wave through the metasurface plate 110-1 is deflected in the -x direction. Referring to the radiation pattern shown in FIG. 31, the transmitted wave through the metasurface plate 110-1 is deflected approximately -30° in the -x direction, resulting in a deflection angle θ of approximately 30°. In this case, the amplitude of the transmitted wave passes through the metasurface plate 110-1 with almost no attenuation.

[0007] As shown by the dashed lines in Figure 28, two or three conventional metasurface plates 110 can be stacked in the z direction at a predetermined interval in the direction of electromagnetic wave propagation. The second and third metasurface plates 110b and 110c have the same configuration as the metasurface plate 110. For example, Figure 32 shows the radiation pattern of the transmitted wave when the three stacked metasurface plates 110, 110b, and 110c shown in Figure 28 are used as the metasurface plate 110-1 configured as shown in Figure 30. In this case, if the free-space wavelength of the operating frequency is λ, the distance between the patch antenna 130 and the first metasurface plate 110 is approximately 1 / 2λ, and the distance between the three metasurface plates 110-1 is approximately 1 / 4λ. In this case, the transmitted wave through the three stacked metasurface plates 110-1 is further deflected in the -x direction. 32, the radiation pattern of the transmitted wave in the three-layered metasurface plate 110-1 is deflected by approximately -60° in the -x direction, resulting in a deflection angle θ of approximately 60°. Furthermore, the amplitude of the transmitted wave passes through the three-layered metasurface plate 110-1 with almost no attenuation. When two metasurface plates 110 and 110b are stacked, a deflection angle θ of approximately 50° can be obtained, although this is not shown.

[0008] Next, Figure 33 shows another configuration of a conventional metasurface plate 110 that can produce a radiation pattern of transmitted waves in two directions. The metasurface plate 110-2 of this configuration shown in Figure 33 is configured by periodically arranging a plurality of unit elements 111b, each consisting of a metal loop element 112b, in the x and y directions on one surface of a dielectric substrate 120. The length St of one side of each square-shaped loop element 112b is fixed, and the line width Wb is gradually narrowed from the center in the x direction toward the ±x directions. In the y direction, the length St of one side of adjacent loop elements 112b and the line width Wb are fixed. In this case, the area where one loop element 112b is formed on the dielectric substrate 120 constitutes a unit element 111b.

[0009] When the metasurface board 110 shown in FIG. 28 is replaced with the metasurface board 110-2 of another configuration shown in FIG. 33, the radiation pattern of the transmitted wave through the metasurface board 110-2 is shown in FIG. 34. In this case, if the free-space wavelength of the operating frequency is λ, the distance between the patch antenna 130 and the metasurface board 110-2 is approximately 1 / 2λ. The narrower the line width Wb of the loop element 112b, the more delayed the transmission phase shift of the unit element 111b including the loop element 112b. Therefore, the transmission phase shift of the transmitted wave through the metasurface board 110-2 becomes increasingly delayed in the +x and -x directions. In other words, the transmitted wave through the metasurface board 110-2 is deflected in the +x and -x directions, resulting in a radiation pattern in two directions. Referring to the radiation pattern shown in FIG. 34, the transmitted wave through the metasurface board 110-2 is deflected approximately ±45 degrees in the ±x directions, resulting in a radiation pattern in two directions. The three-layered metasurface plates 110, 110b, and 110c shown in Figure 28 can be replaced with a metasurface plate 110-2 of another configuration shown in Figure 33. The radiation pattern of the transmitted waves in two directions in the metasurface plate 110-2 of two or three layers stacked has a large deflection angle θ.

[0010] Next, Figure 35 shows another configuration of a conventional metasurface plate 110 that can produce a radiation pattern of transmitted waves in four directions. The metasurface plate 110-3 shown in Figure 35 is configured by forming a plurality of unit elements 111c, each of which is made of a metal loop element 112c, periodically in the x and y directions on one surface of a dielectric substrate 120. The length St of one side of each square-shaped loop element 112c is fixed, and the line width Wc gradually tapers from the center of the dielectric substrate 120 toward the ±x directions, while the line width Wc gradually tapers from the center of the dielectric substrate 120 toward the ±y directions. In this case, the area where one loop element 112c is formed on the dielectric substrate 120 constitutes a unit element 111c.

[0011] The metasurface plate 110 shown in Figure 28 is replaced with a metasurface plate 110-3 of yet another configuration shown in Figure 35. In this case, if the free space wavelength of the operating frequency is λ, the distance between the patch antenna 130 and the metasurface plate 110-3 is approximately 1 / 2λ. The narrower the line width Wc of the loop element 112c, the more delayed the transmission phase shift of the unit element 111c including the loop element 112c, so the transmission phase shift of the transmitted wave through the metasurface plate 110-3 becomes increasingly delayed as it moves from the center in the ±x and ±y directions. In other words, the transmitted wave through the metasurface plate 110-2 is deflected in the ±x and ±y directions, resulting in a radiation pattern in four directions. The three-layered metasurface plates 110, 110b, and 110c shown in Figure 28 can be replaced with a metasurface plate 110-3 having yet another configuration as shown in Figure 35. The radiation pattern of the transmitted waves in the four directions of the metasurface plate 110-3 having two or three layers stacked has a large deflection angle θ. [Prior art documents] [Non-patent literature]

[0012] [Non-Patent Document 1] Grant-in-Aid for Scientific Research Research Report, Organization Number: 32675, Issue Number: 15K06087, Research Title: Multi-polarization beamforming using a low-profile antenna structure with a transparent metasurface plate in front. Principal Investigator: Hisamatsu Nakano [online], [Retrieved December 14, 2021], Internet<https: / / kaken.nii.ac.jp / ja / file / KAKENHI-PROJECT-15K06087 / 15K06087seika.pdf> [Non-patent document 2] H. Nakano, S. Mitsui, and J. Yamauchi, “Tilted-beam high gain antenna system composed of a patch antenna and periodically arrayed loops,” IEEE Transactions on Antennas and Propagation, vol. 54, no. 1, pp. 2917-2925, June 2014. [Non-patent document 3] H. Nakano, M. Toida, S. Okabe, and J. Yamauchi, “Tilted beam formation using parasitic loop-based plates,” IEEE Antennas and Wireless Propagation Letters, vol. 66, pp. 1475-1478, 2016. [Non-patent document 4] H. Nakano, Y. Kameta, and J. Yamauchi, “Increased beam tilt angle from a patch antenna with three inhomogeneous loop-based plates,” IET Electronics Letters, vol. 53, no. 24, pp. 1562-1564, Nov. 2017. Summary of the Invention [Problem to be solved by the invention]

[0013] To avoid communication degradation due to building interference and other factors, it has become necessary to deflect and radiate electromagnetic wave radiation beams in a specific direction. Conventional metasurface plates disclosed in Non-Patent Documents 1-4 can deflect transmitted waves in a specific direction. Non-Patent Documents 1 and 2 show that a single metasurface plate can achieve a deflection angle of up to approximately 30 degrees. Furthermore, Non-Patent Documents 1, 3, and 4 show that adding one or two metasurface plates on top of the first one can increase the deflection angle. A two-layer stacked metasurface plate can achieve a deflection angle of approximately 50 degrees, and a three-layer stacked metasurface plate can achieve a deflection angle of approximately 60 degrees. As described above, conventional metasurface plates require two or more plates to achieve a deflection angle of 30 degrees or more. This means that when a larger deflection angle is required, the number of metasurface plates must be increased, which increases the overall volume of the metasurface plate and increases manufacturing costs.

[0014] Therefore, the present invention aims to provide a metatwin that can obtain a large phase shift in the transmission phase. Also, the present invention aims to provide a metasurface plate that can realize a deflection angle ranging from small to large, exceeding 60 degrees, without increasing the overall volume or manufacturing cost. [Means for solving the problem]

[0015] In order to achieve the above object, the most important feature of the MetaTwin of the present invention is that a basic conductor pattern of a predetermined shape is cut in half to form a first conductor pattern and a second conductor pattern, and the surfaces of the first conductor pattern and the second conductor pattern are kept parallel to each other and separated by a predetermined distance in a direction perpendicular to the surfaces, thereby arranging the first conductor pattern and the second conductor pattern at a predetermined distance apart.

[0016] In addition, in the metatwin of the present invention, the basic conductor pattern may be shaped as a line having a predetermined width, and the first conductor pattern and the second conductor pattern may be shaped as a line having a predetermined width. Furthermore, in the metatwin of the present invention, the first conductor pattern can be formed on one surface of a dielectric substrate, and the second conductor pattern can be formed on the other surface of the dielectric substrate facing the one surface, and the first conductor pattern and the second conductor pattern are arranged point-symmetrically with respect to the center point of the dielectric substrate. Furthermore, in the metatwin of the present invention, the first conductor pattern and the second conductor pattern are formed by cutting half of the basic conductor pattern arranged in the xy plane, and the first conductor pattern and the second conductor pattern, which have the same shape, are composed of an x-direction portion in the x direction and a y-direction portion in the y direction. Furthermore, in the metatwin of the present invention, the length of at least one identical part in the x-direction in the first conductor pattern and the second conductor pattern can be set, and the tips of the identical parts in the first conductor pattern and the second conductor pattern, which have the same shape, may or may not overlap at the specified distance. Furthermore, in the metatwin of the present invention, the transmission phase is set according to the length of the same part. Furthermore, in the metatwin of the present invention, the basic conductor pattern may have a double loop shape consisting of an outer loop and an inner loop of a predetermined width. Furthermore, in the metatwin of the present invention, the first conductor pattern and the second conductor pattern each have a connecting piece of a predetermined width that connects the center of the outer loop to the center of the inner loop. Furthermore, in the metatwin of the present invention, the outer loop and the inner loop connected by the connecting piece may be cut out at the center in the x direction of the connecting piece. Furthermore, in the metatwin of the present invention, the outer loop and the inner loop may be rectangular loops arranged concentrically. Furthermore, in the metatwin of the present invention, the outer loop may be a rectangular loop, and the inner loop may be a rectangular loop that is concentrically arranged and rotated approximately 45 degrees. Furthermore, in the metatwin of the present invention, the first conductor pattern and the second conductor pattern may be T-shaped.

[0017] In order to achieve the above-mentioned object, the metasurface plate of the present invention comprises a second dielectric substrate and a plurality of metatwins as described in any one of claims 1 to 12, which are formed in a periodic arrangement in the x and y directions of the second dielectric substrate, and its most main feature is that the first conductor pattern in the metatwin is formed in a periodic arrangement on the upper surface of the second dielectric substrate, and the second conductor pattern in the metatwin is formed in a periodic arrangement on the lower surface of the second dielectric substrate so as to correspond to the first conductor pattern. In the metasurface plate of the present invention, the metatwins are formed in large numbers and periodically arranged in the x and y directions of the second dielectric substrate, and the transmission phase of each metatwin is set to a predetermined transmission phase, thereby forming a distribution of predetermined transmission phases. In addition, in the metasurface plate of the present invention, the transmission phase in each metatwin is distributed so that it gradually delays in a predetermined direction, and an incident wave incident from one surface of the second dielectric substrate is radiated as a transmission wave deflected in a predetermined direction. Furthermore, in the metasurface plate of the present invention, the phase of the wave radiated from a local wave source and incident on one surface of the second dielectric substrate is set to a phase that corresponds to the distance between the wave source and the incident position on the second dielectric substrate, and the transmission phase in each of the metatwins is set according to the distance. Furthermore, in the metasurface plate of the present invention, an electronic element that adjusts the transmission phase in each metatwin may be mounted on the surface of the second dielectric substrate, and the deflection angle and pattern of the transmitted wave may be adjusted by the electronic element. [Effects of the Invention]

[0018] The metatwin of the present invention is configured such that a first conductor pattern and a second conductor pattern, each formed by cutting a basic conductor pattern of a predetermined shape, are arranged at a distance from each other. This metatwin of the present invention can obtain a large phase change in the transmitted phase. Furthermore, by using the metatwin of the present invention, the metasurface plate of the present invention can achieve a deflection angle for radiating transmitted waves ranging from a small angle to a large angle of 60 degrees or more with a single plate. Furthermore, because the metasurface plate of the present invention can deflect the transmitted wave to the required angle with a single plate, the overall volume can be reduced and manufacturing costs can be lowered. [Brief explanation of the drawings]

[0019] [Figure 1] 1A to 1C are a perspective view, a top view, and a side view showing the configuration of a unit element of a first embodiment having a metatwin of the first embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view illustrating the configuration of a metatwin according to a first embodiment of the present invention. [Figure 3] FIG. 2 is a diagram showing the amplitude characteristics of the transmitted wave with respect to the length Lin in the MetaTwin of the first embodiment of the present invention. [Figure 4] FIG. 10 is a diagram showing the shape of the metatwin of the first embodiment of the present invention when the length Lin is adjusted. [Figure 5] FIG. 1 is a diagram showing the transmission phase characteristics with respect to the length Lin in the metatwin of the first embodiment of the present invention. [Figure 6] FIG. 1 is a plan view showing the configuration of a metasurface plate according to a first embodiment of the present invention, with a portion thereof enlarged. [Figure 7] FIG. 1 is a diagram showing the refraction of a plane wave in the metasurface plate of the first embodiment of the present invention. [Figure 8] This is a diagram showing the refraction of a plane wave in the metasurface plate of the first embodiment of the present invention using an electric field distribution. [Figure 9] This is a plan view showing the configuration of a modified example of the metasurface plate of the first embodiment of the present invention, with a partially enlarged view. [Figure 10] FIG. 10 is a diagram showing the state of refraction when the wave source in a metasurface plate of a modified example of the first embodiment of the present invention is a patch antenna. [Figure 11] This is a diagram showing the refraction state in the case where the wave source in a metasurface plate of a modified example of the first embodiment of the present invention is a patch antenna, using an electric field distribution. [Figure 12] FIG. 10 is a diagram showing the radiation pattern when a predetermined operating frequency wave is used in a metasurface plate according to a modified example of the first embodiment of the present invention. [Figure 13] FIG. 10 is a diagram showing the radiation pattern when a different frequency wave is used in a metasurface plate according to a modified example of the first embodiment of the present invention. [Figure 14] FIG. 10 is a diagram showing the radiation pattern when a different frequency wave is used in a metasurface plate according to a modified example of the first embodiment of the present invention. [Figure 15] FIG. 10 is a diagram showing the frequency characteristics of gain in the maximum radiation direction of a metasurface plate of a modified example of the first embodiment of the present invention. [Figure 16] 10A to 10C are a perspective view, a top view, and a side view showing the configuration of a unit element of a second embodiment of the present invention, which includes a metatwin. [Figure 17] FIG. 10 is a perspective view illustrating the configuration of a metatwin according to a second embodiment of the present invention. [Figure 18] FIG. 10 is a diagram showing the amplitude characteristics of the transmitted wave with respect to the length Lin in the MetaTwin of the second embodiment of the present invention. [Figure 19]FIG. 10 is a diagram showing the transmission phase characteristics with respect to the length Lin in the metatwin of the second embodiment of the present invention. [Figure 20] 10A to 10C are a perspective view, a top view, and a side view showing the configuration of a unit element of a third embodiment of the present invention, which includes a metatwin. [Figure 21] FIG. 10 is a perspective view illustrating the configuration of a metatwin according to a third embodiment of the present invention. [Figure 22] FIG. 10 is a diagram showing the amplitude characteristics of the transmitted wave with respect to the length Lin in the MetaTwin of the third embodiment of the present invention. [Figure 23] FIG. 10 is a diagram showing the transmission phase characteristics with respect to the length Lin in the metatwin of the third embodiment of the present invention. [Figure 24] 10A to 10C are a perspective view, a top view, and a side view showing the configuration of a unit element according to a fourth embodiment of the present invention, the unit element having a metatwin according to the fourth embodiment of the present invention. [Figure 25] FIG. 10 is a perspective view illustrating the configuration of a metatwin according to a fourth embodiment of the present invention. [Figure 26] FIG. 10 is a diagram showing the amplitude characteristics of the transmitted wave with respect to the length Lin in the MetaTwin of the fourth embodiment of the present invention. [Figure 27] FIG. 10 is a diagram showing the transmission phase characteristics with respect to the length Lin in the metatwin of the fourth embodiment of the present invention. [Figure 28] FIG. 1 is a perspective view showing a configuration using a conventional metasurface plate. [Figure 29] FIG. 1 is a plan view showing the configuration of a conventional metasurface plate, with a partially enlarged view. [Figure 30] FIG. 1 is a plan view showing an example of the configuration of a conventional metasurface plate. [Figure 31] FIG. 10 is a diagram showing the radiation pattern of an example configuration of a conventional metasurface plate. [Figure 32] This figure shows the radiation pattern when multiple conventional metasurface plates are stacked. [Figure 33] FIG. 1 is a plan view showing another configuration of a conventional metasurface plate. [Figure 34] 10A and 10B show radiation patterns of conventional metasurface plates with different configurations. [Figure 35] FIG. 10 is a diagram showing yet another configuration of a conventional metasurface plate. DETAILED DESCRIPTION OF THE INVENTION

[0020] <Unit element of the first embodiment having the metatwin of the first embodiment> The configuration of a unit element 1 of a first embodiment of the present invention, which includes a metatwin M1, is shown in Figures 1(a), (b), and (c). Figure 1(a) is a perspective view showing the configuration of a unit element 1 of the first embodiment, Figure 1(b) is a top view showing the configuration of a unit element 1 of the first embodiment, and Figure 1(c) is a side view showing the configuration of a unit element 1 of the first embodiment. Also, Figures 2(a), (b), (c), and (d) are perspective views illustrating the configuration of the metatwin M1 of the first embodiment of the present invention. 1(a), (b), and (c), the unit element 1 of the first embodiment is composed of a dielectric substrate 10 and the metatwin M1 of the first embodiment formed on the upper and lower surfaces of the dielectric substrate 10. The metatwin M1 of the first embodiment is composed of a first conductor pattern 11 formed on the upper surface of the dielectric substrate 10 and a second conductor pattern 12 formed on the lower surface of the dielectric substrate 10.

[0021] Therefore, the metatwin M1 of the first embodiment will be described with reference to Figures 2(a), (b), (c), and (d). Figures 2(a), (b), and (c) show the process of constructing the metatwin M1. The basic conductor pattern of the metatwin M1 is the double loop element Lp1 shown in Figure 2(a). The double loop element Lp1 is composed of an outer loop LPout that is a linear square of a predetermined width and an inner loop LPin that is a linear square of a predetermined width and is arranged concentrically, and the centers of the two opposing sides of the outer loop LPout and the inner loop LPin in the x direction are connected to each other. The double loop element Lp1, which is the basic conductor pattern, is cut in half along the center line CLy in the y direction as shown in Figure 2(b), and a first conductor pattern of the same shape that is line-symmetrical is formed. 11 and the second conductor pattern 12 The first conductor pattern is then separated into 11 is placed on top and the second conductor pattern 12The first conductor pattern is disposed on the bottom of the substrate, and the surfaces of the first conductor pattern and the second conductor pattern are kept parallel to each other and spaced apart by a predetermined distance in a direction perpendicular to the surfaces. 11 and the second conductor pattern 12 and are spaced apart by a predetermined distance Wb in the z direction. 11 and the second conductor pattern 12 The first conductor pattern is 11 and the second conductor pattern 12 Here, as shown in FIG. 2(c), a metatwin M1′ is formed in which the first conductor pattern M1′ is symmetrical with the first conductor pattern M2. 11 The half-cut end of the first conductive pattern 11 is extended in the −x direction to form the second conductive pattern 12. 12 The half-truncated ends of the first and second conductor patterns 11 and 12 are extended the same length in the x direction to form the second conductor pattern 12. This forms a metatwin M1 consisting of the first conductor pattern 11 and the second conductor pattern 12, which have the same shape and whose ends overlap when viewed from the z direction. The metatwin M1 can be easily created by preparing a dielectric substrate 10 with a thickness of Wb, as shown in FIG. 2(d). Specifically, the first conductor pattern 11 is formed on the upper surface of the dielectric substrate 10, and the second conductor pattern 12, indicated by the dashed line, is formed on the lower surface, so that the first conductor pattern 11 and the second conductor pattern 12 are point-symmetric with respect to the center of the dielectric substrate 10. This results in the unit element 1 of the first embodiment, shown in FIGS. 1(a), 1(b), and 1(c), in which the metatwin M1 of the first embodiment is formed on the upper and lower surfaces of the dielectric substrate 10.

[0022] 1(a), 1(b), and 1(c), the first conductor pattern 11 and the second conductor pattern 12 (shown by dashed lines) that constitute the metatwin M1 formed on the top and bottom surfaces of the dielectric substrate 10 are formed in a double U-shape and are point-symmetric with respect to the center O of the dielectric substrate 10, forming a square-shaped double loop element LP1 that serves as the basic conductor pattern when viewed from the z direction. The first conductor pattern 11 is composed of five parts in the x direction and two parts in the y direction. As shown in FIG. 1(b), the five parts in the x direction are composed of parts 11-x-1 and 11-x-3 that constitute the outer loop, parts 11-x-2 and 11-x-4 that constitute the inner loop, and part 11-x-5 that connects the centers of the outer and inner loops. The two parts in the y direction are composed of parts 11-y-1 and 11-y-2, as shown in FIG. 1(a). The second conductor pattern 12, indicated by dashed lines, is also composed of five parts in the x direction and two parts in the y direction. The five parts in the x direction are composed of parts 12-x-1 and 12-x-3 that form an outer loop, parts 12-x-2 and 12-x-4 that form an inner loop, and part 12-x-5 that connects the outer loop and the inner loop, as shown in Fig. 1(b), and the two parts in the y direction are composed of parts 12-y-1 and 12-y-2, as shown in Fig. 1(a).

[0023] The dimensions of the metatwin M1 of the first embodiment are shown in Figure 1(b). The width of the first conductor pattern 11 is length Ls, the length from the tips of parts 11-x-1 and 11-x-3 constituting the outer loop to the center of part 11-y-1 is length Lout, and the length from the tips of parts 11-x-2 and 11-x-4 constituting the inner loop to the center of part 11-y-2 is length Lin. The U-shaped outer loop formed by parts 11-x-1, 11-y-1, and 11-x-3 and the U-shaped inner loop formed by parts 11-x-2, 11-y-2, and 11-x-4 are spaced apart by a distance g, and the outer and inner loops of the first conductor pattern 11 are linear conductor patterns with a width W. The dimensions of each part of the second conductor pattern 12 are the same because the first conductor pattern 11 and the second conductor pattern 12 have the same shape. That is, the length from the tips of parts 12-x-1 and 12-x-3 to the center of part 12-y-1 is Lout, and the length from the tips of parts 12-x-2 and 12-x-4 to the center of part 12-y-2 is Lin, and the U-shaped outer loop formed by parts 12-x-1, 12-y-1, and 12-x-3 and the U-shaped inner loop formed by parts 12-x-2, 12-y-2, and 12-x-4 are arranged with a gap g between them, and the outer loop and inner loop in the second conductor pattern 12 are linear conductor patterns with a width W. Furthermore, the thickness of the dielectric substrate 10 constituting the unit element 1 of the first embodiment is Wb and has a relative dielectric constant εs, as shown in Figure 1(c), and the first conductor pattern 11 and the second conductor pattern 12 are spaced apart by a thickness Wb and are arranged point-symmetrically with respect to the center point O of the dielectric substrate 10, forming a square-shaped double loop element LP1 when viewed from the z direction.

[0024] To give a specific example of dimensions, for the first conductor pattern 11 and the second conductor pattern 12, the physical length of the length Ls is approximately 8 mm, the physical length of the length Lout is approximately 9.4 mm, the physical length of the gap g is approximately 0.4 mm, the physical length of the width W is approximately 0.4 mm, and the length Lin is a set length described below. The physical length of the thickness Wb of the dielectric substrate 10 is approximately 3.2 mm, and the relative dielectric constant εs is approximately 2.6. A dielectric substrate 10 with a relative dielectric constant εs of approximately 2.6 is made of, for example, Teflon (registered trademark), and when the relative dielectric constant εs is approximately 2.6, the wavelength shortening rate is approximately 0.62. If the physical length dimensions of each of the above-mentioned parts are expressed as electrical lengths where the free space wavelength at an operating frequency of 11.5 GHz is λ (≈26.087 mm), then in the first conductor pattern 11 and the second conductor pattern 12, the electrical length of the length Ls is approximately 0.307λ, the electrical length of the thickness Wb of the dielectric substrate 10 is approximately 0.123λ, the electrical length of the length Lout is approximately 0.360λ, the electrical length of the spacing g is approximately 0.015λ, and the electrical length of the width W is approximately 0.015λ.

[0025] The first conductor pattern 11 and the second conductor pattern 12 are formed by applying a metal ink to the surface of the dielectric substrate 10 or by depositing a metal to a predetermined thickness and then etching the metal into the desired shape. However, the method for forming the first conductor pattern 11 and the second conductor pattern 12 is not limited to the above-described method, and other methods may be used. Metals with good conductivity, such as gold, silver, copper, and aluminum, are used as the metal material for forming the first conductor pattern 11 and the second conductor pattern 12. Furthermore, the dielectric substrate 10 is preferably made of a material that does not absorb microwaves, such as Teflon (registered trademark). However, the material is not limited to Teflon (registered trademark), and other materials that do not absorb microwaves may also be used.

[0026] In the metatwin M1 of the first embodiment described above, for example, the length Lout is fixed and the length Lin can be set to a predetermined length. In the metatwin M1 of the first embodiment in which the length Lin is set to a predetermined length, it was found that the transmission phase when the set length Lin is long lags behind the transmission phase when the set length Lin is short. FIG. 3 shows the amplitude characteristics of the transmitted wave versus the set length Lin for the MetaTwin M1 of the first embodiment of the present invention, when the dimensions of each component are the same as those in the example above and the operating frequency f is 11.5 GHz. In FIG. 3, the horizontal axis shows the length Lin, which can be set from 0.0 mm to 9.6 mm, and the vertical axis shows the amplitude of the transmitted wave, expressed as the absolute value [dB] of the S-parameter S21. Referring to FIG. 3, when the length Lin is set to 0.0 mm, the amplitude of the transmitted wave is approximately -1 dB. As the length Lin is increased from 0.0 mm to approximately 1.6 mm, the amplitude of the transmitted wave increases, reaching approximately -0.1 dB when the length Lin is set to approximately 1.6 mm. FIG. 4(a) shows the shape of the MetaTwin M1 of the first embodiment when the length Lin is set to 1.6 mm. When the length Lin is set to exceed 1.6 mm, the amplitude of the transmitted wave decreases, reaching approximately -2 dB when set to approximately 2.2 mm. As the length Lin exceeds approximately 2.2 mm, the amplitude of the transmitted wave increases, reaching approximately -0.1 dB when the length Lin is set to approximately 2.6 mm. As the length Lin is set to exceed approximately 2.6 mm, the amplitude of the transmitted wave gradually decreases, reaching a valley of approximately -1.4 dB when the length Lin is set to approximately 5.8 mm. Thereafter, the amplitude of the transmitted wave gradually increases as the length Lin increases. Figure 4(b) shows the shape of the MetaTwin M1 of the first embodiment when the length Lin is set to 4.8 mm, and Figure 4(c) shows the shape of the MetaTwin M1 of the first embodiment when the length Lin is set to 8.0 mm. The amplitude of the transmitted wave is approximately 0.0 dB when the length Lin is set to approximately 8.8 mm, and decreases as the length Lin is set to 9.6 mm, reaching approximately -3.1 dB when the length Lin is set to 9.6 mm. Thus, the MetaTwin M1 of the first embodiment is able to transmit almost all of the incident power even when the length Lin is set to a length between 0.0 mm and 9.6 mm. Note that Figures 4(a), (b), and (c) are perspective views of the MetaTwin M1 of the first embodiment from the z direction.

[0027] Next, Fig. 5 shows the transmission phase characteristics for the set length Lin of the MetaTwin M1 of the first embodiment of the present invention when the dimensions of each part are the same as those in the example above and the operating frequency f is 11.5 GHz. In Fig. 5, the horizontal axis shows the length Lin from 0.0 mm to 9.6 mm, and the vertical axis shows the transmission phase expressed in degrees (deg) of the S-parameter S21. Figures 4(a), (b), and (c) show the shapes of the MetaTwin M1 of the first embodiment when the length Lin is set to 1.6 mm, 4.8 mm, and 8.0 mm. Referring to Fig. 5, the transmission phase is approximately -45 degrees when the length Lin is set to 0.0 mm. As the length Lin increases to 1.6 mm, the transmission phase delays, and when the length Lin is set to 1.6 mm, the transmission phase is approximately -100 degrees. As the length Lin exceeds 1.6 mm, the transmission phase rapidly delays, resulting in a transmission phase of approximately -330 degrees when the length Lin is set to approximately 3 mm. As the length Lin exceeds 3 mm, the transmission phase gradually delays further, resulting in a transmission phase of approximately -400 degrees when the length Lin is set to approximately 8 mm. As the length Lin exceeds 8 mm and increases to 9.6 mm, the transmission phase delays further, resulting in a transmission phase of approximately -475 degrees when the length Lin is set to 9.6 mm. Thus, in the MetaTwin M1 of the first embodiment, the transmission phase is approximately -45 degrees when the length Lin is set to 0.0 mm and approximately -475 degrees when the length Lin is set to 9.6 mm. Therefore, increasing the length Lin from 0.0 mm to 9.6 mm can achieve a phase change in the transmission phase of approximately 430 degrees (= -45 degrees - (-475 degrees) = 430 degrees), which exceeds 360 degrees. In this case, most of the incident power can be transmitted as described above.

[0028] <Metasurface plate of the first embodiment> A plan view showing the configuration of a metasurface board 1-1 according to a first embodiment of the present invention is shown in Fig. 6. Fig. 6 shows an enlarged view of part of the configuration. The metasurface plate 1-1 of the first embodiment of the present invention is a transmissive metasurface plate. As shown in FIG. 6, it is composed of a dielectric substrate 10-1 having a square cross section in the height direction and a number of metatwins M1 of the first embodiment periodically arranged on the upper and lower surfaces of the dielectric substrate 10-1. The metatwins M1 of the first embodiment are arranged in equal numbers in the x and y directions. Although FIG. 6 only shows the first conductor patterns 11 in the many metatwins M1 of the first embodiment periodically arranged on the upper surface of the dielectric substrate 10-1, as shown in the partially enlarged view, the metatwin M1 of the first embodiment is composed of the first conductor patterns 11 formed on the upper surface of the dielectric substrate 10-1 and the second conductor patterns 12 formed on the lower surface of the dielectric substrate 10-1. The partially enlarged view shows a unit element 1 including the dielectric substrate 10-1 and the metatwin M1 of the first embodiment, which is composed of the first conductor patterns 11 and the second conductor patterns 12 formed on the upper and lower surfaces of the dielectric substrate 10-1. That is, the metasurface board 1-1 of the first embodiment is configured by periodically arranging unit elements 1, shown in the partially enlarged view, in the x and y directions, and the unit elements 1 are considered to be the constituent units that make up the metasurface board 1-1 of the first embodiment.

[0029] In the metasurface plate 1-1 of the first embodiment shown in FIG. 6, the length Lout of the metatwins M1 of the first embodiment, which are periodically arranged on the dielectric substrate 10-1, is fixed, and the length Lin is set to decrease in the x direction. The length Lin in the y direction is fixed. As can be seen from the shape of the first conductor pattern 11 shown in FIG. 6, the length Lin of the metatwin M1 of the first embodiment in the top row in FIG. 6 is the longest, and the length Lin decreases toward the lower rows in the x direction. This results in a transmission phase distribution in which the transmission phase of the metatwin M1 of the first embodiment in the top row is the most delayed, the transmission phase of the metatwin M1 of the first embodiment in the bottom row is the most advanced, and the transmission phase of the metatwin M1 of the first embodiment gradually delays from the bottom row to the top row. Due to the effect of this transmission phase distribution, the transmitted wave in the metasurface plate 1-1 of the first embodiment is deflected in the -x direction. The physical vertical dimension of the dielectric substrate 10-1 in the x direction and the physical horizontal dimension in the y direction are the same length L1a, and for example, the physical dimension of length L1a is about 110 mm.

[0030] FIG. 7 shows the refraction of a plane wave in the metasurface plate 1-1 of the first embodiment of the present invention. In FIG. 7, a plane wave is incident on one surface of the metasurface plate 1-1 of the first embodiment. The incident plane wave passes through each metatwin M1 formed on the metasurface plate 1-1 of the first embodiment, and the transmitted wave has a transmission phase affected by each metatwin M1. As described above, the degree of transmission phase in each metatwin M1 of the first embodiment is gradually delayed from the bottom row to the top row. Based on this transmission phase distribution, the transmitted wave emitted from the metasurface plate 1-1 of the first embodiment is refracted by an angle θ2 in the -x direction and deflected before being emitted. The desired deflection angle θ2 can be obtained by setting the length L in each metatwin M1 of the first embodiment, which is formed in a periodic array on the top and bottom surfaces of the dielectric substrate 10-1, to a predetermined length. The desired angle θ2 is generally set to 30 to 60 degrees, but can be set to an angle that deflects light beyond 60 degrees. In this way, the metasurface plate 1-1 of the first embodiment can deflect light beyond 60 degrees.

[0031] The refraction of a plane wave in the metasurface plate 1-1 of the first embodiment of the present invention is shown in the form of an electric field distribution in Figure 8. The operating frequency f is set to 11.5 GHz. Referring to Figure 8, the plane wave is incident on the metasurface plate 1-1 of the first embodiment at an angle θ1 of 0 degrees. The transmitted wave emitted from the metasurface plate 1-1 is refracted and emitted at an angle θ2 of approximately 65 degrees. As described above, the metasurface plate 1-1 of the first embodiment of the present invention can achieve a deflection angle of more than 60 degrees by using only one metasurface plate 1-1, thereby reducing the overall volume and manufacturing costs. Furthermore, whether a plane wave is incident on the bottom or top surface of the metasurface plate 1-1 of the first embodiment, a similarly deflected transmitted wave is emitted. In other words, since the metasurface plate 1-1 of the first embodiment is reversible, it can be used as a metasurface plate that can radiate in the desired direction when transmitting and can also receive from the desired direction.

[0032] <Modification of the metasurface plate of the first embodiment> Next, FIG. 9 shows an enlarged plan view of a portion of the configuration of a metasurface board 1-2, which is a modified example of the metasurface board 1-1 of the first embodiment of the present invention. The metasurface plate 1-2 of the modified first embodiment of the present invention is a transmission-type metasurface plate. As shown in FIG. 9, the metasurface plate 1-2 of the modified first embodiment has a configuration similar to that of the metasurface plate 1-1 of the first embodiment. The metasurface plate 1-2 of the modified first embodiment is composed of a dielectric substrate 10-2 having a square cross section in the height direction and a number of metatwins M1 of the first embodiment formed in a periodic array on the upper and lower surfaces of the dielectric substrate 10-2. However, the distribution of the length settings of the length Lin of each of the many metatwins M1 of the first embodiment differs from that of the metasurface plate 1-1 of the first embodiment. The metasurface plate 1-2 of the modified first embodiment is designed to deflect the transmitted wave in a predetermined direction when the wave source radiating the incident wave is a localized wave source. This will be explained with reference to FIG. 10. In FIG. 10, the metasurface plate 1-2 of the modified first embodiment and a metal ground plate G are arranged parallel to each other, spaced apart by a distance d, with their central axes approximately aligned. A patch antenna AN formed on an antenna substrate BP is placed in the center of the upper surface of the ground plate G. It can be seen that the distance between the patch antenna AN and the bottom surface of the metasurface plate 1-2 of the modified first embodiment is shortest at the center of the metasurface plate 1-2 and increases from the center to the periphery. The phase of the incident wave radiated from the patch antenna AN and incident on the bottom surface of the metasurface plate 1-2 of the modified first embodiment corresponds to the distance between the metasurface plate 1-2 and the patch antenna AN. In other words, the phase of the incident wave incident on the periphery of the metasurface plate 1-2 lags behind the phase of the incident wave incident on the center of the metasurface plate 1-2 as it moves from the center to the periphery. In this way, even if the phase of the incident wave incident on the underside of the metasurface plate 1-2 of the modified example of the first embodiment is distributed differently from that of a plane wave, the transmission phase of each metatwin M1 of the first embodiment in the metasurface plate 1-2 is set according to the phase corresponding to the distance from the patch antenna AN so that the transmitted wave of the metasurface plate 1-2 is deflected in a predetermined direction.Here, a wave source consisting of a local radiation source, such as a patch antenna AN, is referred to as a local wave source. The physical vertical dimension in the x direction and the physical horizontal dimension in the y direction of the dielectric substrate 10-2 are the same length L1a. For example, the physical length L1a is approximately 110 mm. The dimensions of the ground plate G are the same as those of the dielectric substrate 10-2. If the free space wavelength of the operating frequency f is λ, the spacing d can be approximately 0.25λ, approximately 0.5λ, approximately 0.75λ, or an integer multiple of approximately 0.25λ. However, the spacing d is not limited to these values ​​and may be other spacings.

[0033] FIG. 10, described above, illustrates the refraction behavior of a patch antenna AN in which the wave source in the metasurface plate 1-2 of the modified first embodiment of the present invention is a localized wave source. While redundant explanations will be omitted, as shown in FIG. 10, the radiated wave from the patch antenna AN is incident on one surface of the metasurface plate 1-2 of the modified first embodiment. The radiated wave from the patch antenna AN passes through each metatwin M1 formed on the metasurface plate 1-2 of the modified first embodiment, and the transmitted wave has a transmission phase affected by each metatwin M1. In this case, even if the phase of the radiated wave incident on the bottom surface of the metasurface plate 1-2 of the modified first embodiment is distributed differently from that of a plane wave, the transmission phase of each metatwin M1 is set so that the transmitted wave from the metasurface plate 1-2 has a transmission phase distribution that deflects it in a predetermined direction. As a result, the transmitted wave radiated from the metasurface plate 1-2 of the modified first embodiment is refracted and deflected by a predetermined angle in the x direction. The desired angle can be obtained by setting the length Lin of the numerous metatwins M1 of the first embodiment, which are periodically arranged on the upper and lower surfaces of the dielectric substrate 10-2, to a predetermined length. The desired angle is generally between 30 and 60 degrees, but can also be set to an angle exceeding 60 degrees. In this way, the metasurface plate 1-2 of the modified first embodiment can also achieve deflection exceeding 60 degrees.

[0034] Next, Figure 11 shows the electric field distribution of refraction when the wave source in the metasurface plate 1-2 of the modified example of the first embodiment of the present invention is a patch antenna AN. The operating frequency f is set to 11.5 GHz. Referring to Figure 11, the incident wave radiated radially from the patch antenna AN is incident on one surface of the metasurface plate 1-2 of the modified example of the first embodiment. The transmitted wave radiated from the metasurface plate 1-2 of the modified example is refracted and radiated, with a deflection angle θ2 of approximately 65 degrees. Thus, even with the metasurface plate 1-2 of the modified first embodiment of the present invention, a deflection angle of more than 60 degrees can be obtained by using only one metasurface plate 1-2 of the modified first embodiment, thereby reducing the overall volume and manufacturing costs. Furthermore, whether a radial incident wave is incident from the bottom or top surface of the metasurface plate 1-2 of the modified first embodiment, a similarly deflected transmitted wave is emitted. In other words, since the metasurface plate 1-2 of the modified first embodiment is also reversible, it can be used as a metasurface plate that can radiate in a desired direction when transmitting and receive from a desired direction.

[0035] Next, Figure 12 shows the radiation pattern when using only one metasurface plate 1-2 of the modified first embodiment of the present invention at an operating frequency f of 11.1 GHz. As shown in Figure 12, the transmitted wave from the modified metasurface plate 1-2 is emitted as a beam focused at an angle of approximately 65 degrees. In this case, the amplitude of the transmitted wave is slightly attenuated by approximately -2 dB. In addition, a beam with an amplitude attenuated to less than -10 dB is emitted in the direction from approximately 30 degrees to -90 degrees. Figure 13 shows the radiation pattern when only one metasurface plate 1-2 of the modified first embodiment of the present invention is used and the operating frequency f is set to 11.5 GHz. As shown in Figure 13, the transmitted wave from the modified metasurface plate 1-2 is emitted as a beam focused at an angle of approximately 65 degrees. In this case, the amplitude of the transmitted wave is set to an amplitude that is not attenuated, i.e., approximately 0 dB. In addition, beams with amplitudes attenuated to -15 dB or less are emitted in directions of approximately 5 degrees and approximately -60 degrees. Furthermore, Figure 14 shows the radiation pattern when using only one metasurface plate 1-2 of the modified first embodiment of the present invention at an operating frequency f of 11.9 GHz. As shown in Figure 14, the transmitted wave from the modified metasurface plate 1-2 is emitted as a beam focused at an angle of approximately 65 degrees. In this case, the amplitude of the transmitted wave is slightly attenuated by approximately -2 dB. In addition, a beam with an amplitude attenuated to less than -10 dB is emitted in the direction from approximately -10 degrees to -45 degrees. 12 to 14, the length Lin of each MetaTwin M1 is set with a design frequency F of 11.5 GHz, so the radiation patterns are best when the operating frequency f is 11.5 GHz. However, a sufficiently practical radiation pattern can also be obtained when the operating frequency f is 11.1 GHz to 11.9 GHz.

[0036] Next, Fig. 15 shows the frequency characteristics of the gain in the maximum radiation direction when the metasurface plate 1-2 of the modified first embodiment of the present invention is used and when no metasurface plate is used. In Fig. 15, the horizontal axis represents the frequency from 10.5 GHz to 12.5 GHz, and the vertical axis represents the gain in the maximum radiation direction (Gain(θ=θmax) [dBi]). In Fig. 15, the gain in the maximum radiation direction when the metasurface plate 1-2 of the modified first embodiment is used is represented by GainA, and the gain in the maximum radiation direction when no metasurface plate is used is represented by GainB. Referring to Fig. 15, when GainA is used with the modified metasurface plate 1-2, a gain of approximately 9 dBi or more in the maximum radiation direction is obtained in the frequency range of 10.5 GHz to 12.5 GHz, and a large gain of approximately 16 dBi in the maximum radiation direction is obtained in the frequency range of 11.3 GHz to 11.8 GHz. In contrast, when the metasurface plate is not used, Gain B only achieves a maximum gain of approximately 6.5 dBi in the maximum radiation direction in the frequency range of 10.5 GHz to 12.5 GHz. Thus, by using the metasurface plate 1-2 according to the modified example of the first embodiment of the present invention, a large gain can be obtained in the maximum radiation direction.

[0037] <Second embodiment unit element having a metatwin of the second embodiment> The configuration of a unit element 2 of a second embodiment of the present invention, which includes a metatwin M2, is shown in Figures 16(a), (b), and (c). Figure 16(a) is a perspective view showing the configuration of a unit element 2 of the second embodiment, Figure 16(b) is a top view showing the configuration of a unit element 2 of the second embodiment, and Figure 16(c) is a side view showing the configuration of a unit element 2 of the second embodiment. Also, Figure 17 is a perspective view illustrating the configuration of a metatwin M2 of the second embodiment of the present invention. As shown in Figures 16(a), 16(b), and 16(c), the unit element 2 of the second embodiment is composed of a dielectric substrate 20 and a metatwin M2 of the second embodiment formed on the upper and lower surfaces of the dielectric substrate 20. The metatwin M2 of the second embodiment is composed of a first conductor pattern 21 formed on the upper surface of the dielectric substrate 20 and a second conductor pattern 22 formed on the lower surface of the dielectric substrate 20. The first conductor pattern 21 and the second conductor pattern 22 have the same shape and are shaped point-symmetrically with respect to the center O of the dielectric substrate 20 as shown in Figure 16(c). The first conductor pattern 21 is composed of two conductor patterns, a first conductor pattern 21a and a first conductor pattern 21b, which are shaped in line symmetry, and the second conductor pattern 22 is composed of two conductor patterns, a second conductor pattern 22a and a second conductor pattern 22b, which are shaped in line symmetry.

[0038] The metatwin M2 of the second embodiment will be described with reference to FIG. 17. FIG. 17 shows the configuration of the metatwin M2 of the second embodiment, in which a conductor pattern 21 consisting of first conductor patterns 21a and 21b is arranged on top, and a conductor pattern 22 consisting of second conductor patterns 22a and 22b that are point-symmetrical to and have the same shape as the first conductor pattern 21 is arranged on the bottom, with the two patterns spaced apart by a predetermined distance Wb2 in the z direction. This forms the metatwin M2 in which the first conductor pattern 21 and the second conductor pattern 22 are shaped point-symmetrical with respect to the center of the space formed by the spaced-apart first conductor pattern 21 and second conductor pattern 22. When the first conductor pattern 21 and the second conductor pattern 22 are viewed from the z direction, a double-loop element is formed, whose basic conductor pattern is composed of an outer loop that is a linear square of a predetermined width and an inner loop that is concentrically arranged and also has a linear square of a predetermined width. The process of constructing the metatwin M2 of the second embodiment is similar to the process of constructing the metatwin M1 of the first embodiment described above. In the double loop element that constitutes the metatwin M2, a groove is provided in the center of the connecting piece that connects the central portions of two opposing sides of the outer loop and inner loop in the x direction, and the connecting piece is cut. The double loop element, which is the basic conductor pattern, is cut in half along the center line in the y direction to separate it into first conductor pattern 21 and second conductor pattern 22, which are line-symmetric and have the same shape. As a result, first conductor pattern 21 is composed of first conductor pattern 21a and first conductor pattern 21b, which are line-symmetric, and second conductor pattern 22 is composed of second conductor pattern 22a and second conductor pattern 22b, which are line-symmetric.

[0039] Then, the first conductor pattern 21 is placed on top and the second conductor pattern 22 is placed on the bottom, with their surfaces kept parallel and separated by a predetermined distance Wb2 in the z direction, which is the direction perpendicular to the surfaces. This results in a metatwin M2 of the second embodiment, in which the first conductor pattern 21 and the second conductor pattern 22 are point-symmetric with respect to the center of the space formed by the spaced-apart first conductor pattern 21 and second conductor pattern 22. The first conductor pattern 21 can be formed by extending the half-truncated tip of the first conductor pattern 21 in the -x direction, and the second conductor pattern 22 can be formed by extending the half-truncated tip of the second conductor pattern 22 by the same length in the x direction. By extending them in this manner, the metatwin M2 of the second embodiment is formed, consisting of the first conductor pattern 21 and the second conductor pattern 22 that have the same shape and whose tips overlap when viewed from the z direction. The unit element 2 of the second embodiment is constructed by forming the metatwin M2 of the second embodiment described above on the upper and lower surfaces of a dielectric substrate 20. That is, a dielectric substrate 20 having a thickness Wb2 is prepared, and the first conductor pattern 21, consisting of the first conductor pattern 21a and the first conductor pattern 21b, and the second conductor pattern 22, consisting of the second conductor pattern 22a and the second conductor pattern 22b, are formed on the upper surface and the lower surface of the dielectric substrate 20, respectively, so that they are point-symmetric with respect to the center O of the dielectric substrate 20. In this way, the unit element 2 of the second embodiment shown in FIGS. 16(a), 16(b), and 16(c) can be obtained, in which the metatwin M2 of the second embodiment is formed on the upper and lower surfaces of the dielectric substrate 20.

[0040] 16(a), 16(b), and 16(c), the first conductor pattern 21 and the second conductor pattern 22 indicated by the dashed lines that constitute the metatwin M2 formed on the upper and lower surfaces of the dielectric substrate 20 are double U-shaped and point-symmetric with respect to the center O of the dielectric substrate 20, forming a square-shaped double loop element that is the basic conductor pattern when viewed from the z direction. The first conductor pattern 21 is composed of the first conductor pattern 21a and the first conductor pattern 21b that are shaped symmetric with respect to the axis, and the first conductor pattern 21a and the first conductor pattern 21b are each composed of three parts in the x direction and two parts in the y direction. The three parts in the x direction of the first conductor pattern 21a are composed of part 21a-x-1 that forms an outer loop, part 21a-x-2 that forms an inner loop, and part 21a-x-5 that connects the outer loop and the inner loop, as shown in Fig. 16(b), and the two parts in the y direction are composed of part 21a-y-1 and part 21a-y-2, as shown in Fig. 16(a).The three parts in the x direction of the first conductor pattern 21b are composed of part 21b-x-1 that forms an outer loop, part 21b-x-2 that forms an inner loop, and part 21b-x-5 that connects the outer loop and the inner loop, as shown in Fig. 16(b), and the two parts in the y direction are composed of part 21b-y-1 and part 21b-y-2, as shown in Fig. 16(a).

[0041] Furthermore, second conductor pattern 22, indicated by dashed lines, is composed of second conductor patterns 22a and 22b, which are symmetrical about an axis, and second conductor patterns 22a and 22b are each composed of three parts in the x direction and two parts in the y direction. As shown in Fig. 16(b), the three parts in the x direction of second conductor pattern 22a are composed of part 22a-x-1 that constitutes an outer loop, part 22a-x-2 that constitutes an inner loop, and part 22a-x-5 that connects the outer loop and the inner loop, and the two parts in the y direction are composed of part 22a-y-1 and part 22a-y-2, as shown in Fig. 16(a). Furthermore, the three parts in the x direction of the second conductor pattern 22b are composed of part 22b-x-1 that forms an outer loop, part 22b-x-2 that forms an inner loop, and part 22b-x-5 that connects the outer loop and the inner loop, as shown in Figure 16(b), and the two parts in the y direction are composed of part 22b-y-1 and part 22b-y-2, as shown in Figure 16(a).

[0042] The dimensions of each part of the metatwin M2 of the second embodiment are the same as those of the metatwin M1 of the first embodiment. The width of the first conductor pattern 21 and the conductor pattern 22 is length Ls2, and in the first conductor pattern 21, the length from the tips of the parts 21a-x-1 and 21b-x-3 constituting the outer loop to the center of the first conductor pattern 21 is length Lout, and the length from the tips of the parts 21a-x-2 and 21b-x-4 constituting the inner loop to the center of the first conductor pattern 21 is length Lin. In the second conductor pattern 22, the length from the tips of the parts 22a-x-1 and 22b-x-3 constituting the outer loop to the center of the second conductor pattern 22 is length Lout, and the length from the tips of the parts 22a-x-2 and 22b-x-4 constituting the inner loop to the center of the second conductor pattern 22 is length Lin. Furthermore, the thickness of the dielectric substrate 20 constituting the unit element 2 of the second embodiment is Wb2 and has a relative dielectric constant εs, as shown in FIG. 16(c), and the first conductor pattern 21 and the second conductor pattern 22 are spaced apart by a thickness Wb2 and are arranged point-symmetrically with respect to the center point O of the dielectric substrate 20, forming a square-shaped double loop element when viewed from the z direction.

[0043] Here, an example of the dimensions of each part of the unit element 2 of the second embodiment is expressed in terms of electrical length, with the free space wavelength at an operating frequency of 11.5 GHz being λ (≈26.087 mm). In the first conductor pattern 21 and the second conductor pattern 22, the electrical length of the length Ls2 is approximately 0.307λ, the electrical length of the length Lout is approximately 0.360λ, the electrical length of the gap g is approximately 0.015λ, and the electrical length of the width W is approximately 0.015λ. The length Lin is a set length, as described below. The electrical length of the thickness Wb2 of the dielectric substrate 20 is approximately 0.123λ. The dielectric substrate 20 is made of, for example, Teflon (registered trademark), and has a relative dielectric constant εs of approximately 2.6. The wavelength shortens according to the relative dielectric constant εs. When the relative dielectric constant εs is 2.6, the wavelength shortening rate is approximately 0.62.

[0044] The first conductor pattern 21 and the second conductor pattern 22 are formed by applying a metal ink to the surface of the dielectric substrate 20 or by depositing a metal onto the surface to a predetermined thickness and then etching the metal into the desired shape. However, the method for forming the first conductor pattern 21 and the second conductor pattern 22 is not limited to the above-described method, and other methods may be used. Metals with good conductivity, such as gold, silver, copper, and aluminum, are used as the metal material for forming the first conductor pattern 21 and the second conductor pattern 22. Furthermore, the dielectric substrate 20 is preferably made of a material that does not absorb microwaves, such as Teflon (registered trademark). However, the material is not limited to Teflon (registered trademark), and other materials that do not absorb microwaves may also be used.

[0045] In the metatwin M2 of the second embodiment described above, for example, the length Lout is fixed and the length Lin can be set to a predetermined length. Even in the metatwin M2 of the second embodiment in which the length Lin is set to a predetermined length, it was found that the transmission phase when the set length Lin is long lags behind the transmission phase when the set length Lin is short. Here, Fig. 18 shows the amplitude characteristics of the transmitted wave versus the set length Lin for the MetaTwin M2 of the second embodiment of the present invention, when the dimensions of each part are the same as those in the example above and the operating frequency f is 11.5 GHz. In Fig. 18, the horizontal axis shows the length Lin, which can be set from 0.0 mm to 9.6 mm, and the vertical axis shows the amplitude of the transmitted wave, expressed as the absolute value [dB] of the S-parameter S21. Referring to Fig. 18, when the length Lin is set to approximately 0.4 mm, the amplitude of the transmitted wave is approximately -0.9 dB. As the length Lin is increased to approximately 1.7 mm, the amplitude of the transmitted wave increases, and when the length Lin is set to approximately 1.7 mm, the amplitude is approximately -0.1 dB. When the length Lin is set to greater than 1.7 mm, the amplitude of the transmitted wave decreases, reaching approximately -2.1 dB when the length Lin is set to approximately 2.4 mm. As the length Lin exceeds approximately 2.4 mm, the amplitude of the transmitted wave increases, reaching approximately -0.1 dB when the length Lin is set to approximately 3.0 mm. As the length Lin is set to greater than approximately 3.0 mm, the amplitude of the transmitted wave gradually decreases, reaching a valley of approximately -1.2 dB when the length Lin is set to approximately 5.1 mm. Thereafter, the amplitude of the transmitted wave gradually increases as the set length increases. The amplitude of the transmitted wave reaches approximately 0.0 dB when the length Lin is set to approximately 8.3 mm, and decreases as the length Lin is set to approximately 9.0 mm, reaching approximately -2.8 dB when the length Lin is set to approximately 9.0 mm. In this way, the MetaTwin M2 of the second embodiment can transmit almost all of the incident power even when the length Lin is set to a value between 0.4 mm and 9.0 mm.

[0046] Next, FIG. 19 shows the transmission phase characteristics for the set length Lin of the MetaTwin M2 according to the second embodiment of the present invention, when the dimensions of each component are the same as those in the example above and the operating frequency f is 11.5 GHz. In FIG. 19, the horizontal axis represents the length Lin, which can be set from 0.0 mm to 9.6 mm, and the vertical axis represents the transmission phase, expressed in degrees (deg) of the S-parameter S21. Referring to FIG. 19, when the length Lin is set to approximately 0.4 mm, the transmission phase is approximately -50 degrees. As the length Lin increases to approximately 1.6 mm, the transmission phase gradually lags, reaching approximately -90 degrees when the length Lin is set to approximately 1.6 mm. As the length Lin exceeds 1.6 mm, the transmission phase rapidly lags, resulting in a transmission phase of approximately -310 degrees when the length Lin is set to approximately 3 mm. As the length Lin exceeds 3 mm, the transmission phase gradually delays further, resulting in a transmission phase of approximately -405 degrees when the length Lin is set to approximately 8 mm. As the length Lin exceeds 8 mm and increases to approximately 9.0 mm, the transmission phase delays further, resulting in a transmission phase of -465 degrees when the length Lin is set to approximately 9.0 mm. Thus, in the MetaTwin M2 of the second embodiment, the transmission phase is approximately -50 degrees when the length Lin is set to approximately 0.4 mm and approximately -465 degrees when the length Lin is set to approximately 9.0 mm. Therefore, increasing the length Lin from approximately 0.4 mm to approximately 9.0 mm results in a phase change in the transmission phase of approximately 415 degrees (= -50 degrees - (-465 degrees) = 415 degrees), exceeding 360 degrees. In this case, as described above, most of the incident power can be transmitted.

[0047] <Second Example of Metasurface Plate> The metatwin M2 of the second embodiment of the present invention can be applied to a metasurface plate in the same manner as the metatwin M1 of the first embodiment. A metasurface plate using the metatwin M2 of the second embodiment is referred to as the metasurface plate of the second embodiment. The metasurface plate of the second embodiment of the present invention is a transmission-type metasurface plate. The metatwin M2 of the second embodiment of the present invention can be periodically arranged on the upper and lower surfaces of a dielectric substrate similar to the dielectric substrate 10, whose cross section in the height direction is square, to form a metasurface plate of the second embodiment (not shown). The metasurface plate of the second embodiment configured in this manner is configured by replacing the metatwin M1 of the first embodiment in the metasurface plate 1-1 of the first embodiment with the metatwin M2 of the second embodiment. That is, the metasurface plate of the second embodiment is composed of a dielectric substrate and a large number of metatwins M2 of the second embodiment periodically arranged on the upper and lower surfaces of the dielectric substrate. In this case, the metatwins M2 of the second embodiment are formed on the dielectric substrate in equal numbers in the x and y directions of the dielectric substrate, similar to the metasurface plate 1-1 of the first embodiment. The metasurface plate of the second embodiment is configured by periodically arranging the unit elements 2 of the second embodiment shown in Figures 16(a), (b), and (c) in the x and y directions, and the unit elements 2 are used as the constituent units that make up the metasurface plate of the second embodiment. In addition, the dielectric substrate in the metasurface plate of the second embodiment is square, with physical dimensions of approximately 110 mm, for example, on one side.

[0048] In the metasurface plate of the second embodiment, the length Lin of each metatwin M2 of the multiple metatwins M2 of the second embodiment is set to a predetermined length. When the length Lin is set to a predetermined length corresponding to the incident plane wave, the transmission phase is gradually delayed, resulting in a transmission phase distribution in which the transmitted wave can be deflected in a predetermined direction, for example, by 65 degrees, similar to the refraction of a plane wave in the metasurface plate 1-1 of the first embodiment shown in Figures 7 and 8. When the length Lin is set to a predetermined length corresponding to the incident wave from a local wave source, the transmission phase distribution is such that the transmitted wave is deflected in a predetermined direction, for example, by 65 degrees, similar to the refraction in the case of a local wave source in the metasurface plate 1-1 of the first embodiment shown in Figures 10 and 11. In this case, the radiation pattern when only one metasurface plate of the second embodiment is used is approximately the same as the radiation pattern of the metasurface plate 1-2 of the modified first embodiment shown in Figures 12, 13, and 14. In this way, with the metasurface plate of the second embodiment, it is possible to obtain the desired deflection angle of 30 degrees or more than 60 degrees by using just one metasurface plate of the second embodiment, thereby reducing the overall volume and lowering manufacturing costs. Furthermore, when comparing the frequency characteristics of the gain in the maximum radiation direction when the metasurface plate 2 of the second embodiment of the present invention is used with the frequency characteristics when no metasurface plate is used, the frequency characteristics of the gain in the maximum radiation direction are almost the same as the frequency characteristics of the gain in the maximum radiation direction for the metasurface plate 1-2 of the modified example of the first embodiment shown in Figure 15, and when the metasurface plate of the second embodiment of the present invention is used, a large gain can be obtained in the maximum radiation direction.

[0049] <Unit element of the third embodiment having the metatwin of the third embodiment> The configuration of a unit element 3 of a third embodiment of the present invention, which includes a metatwin M3, is shown in Figures 20(a), (b), and (c). Figure 20(a) is a perspective view showing the configuration of a unit element 3 of the third embodiment, Figure 20(b) is a top view showing the configuration of a unit element 3 of the third embodiment, and Figure 20(c) is a side view showing the configuration of a unit element 3 of the third embodiment. Also, Figure 21 is a perspective view illustrating the configuration of a metatwin M3 of the third embodiment of the present invention. As shown in Figures 20(a), (b), and (c), the unit element 3 of the third embodiment is composed of a dielectric substrate 30 and the metatwin M3 of the third embodiment formed on the upper and lower surfaces of the dielectric substrate 30. The metatwin M3 of the third embodiment is composed of a first conductor pattern 31 formed on the upper surface of the dielectric substrate 30 and a second conductor pattern 32 formed on the lower surface of the dielectric substrate 30. The first conductor pattern 31 and the second conductor pattern 32 have the same shape and are shaped point-symmetrically with respect to the center O of the dielectric substrate 30 shown in Figure 20(c).

[0050] The metatwin M3 of the third embodiment will be described with reference to Fig. 21. Fig. 21 shows the configuration of the metatwin M3 of the third embodiment, in which a first conductor pattern 31 is disposed on top, and a second conductor pattern 32 that is point-symmetrical to and has the same shape as the first conductor pattern 31 is disposed on the bottom, with the two patterns spaced apart in the z direction by a predetermined distance Wb3. This forms a metatwin M3 in which the first conductor pattern 31 and the second conductor pattern 32 are shaped to be point-symmetrical with respect to the center of the space formed by the spaced-apart first conductor pattern 31 and second conductor pattern 32. The first conductor pattern 31 and the second conductor pattern 32 are shaped like a linear T with a predetermined width. The unit element 3 of the third embodiment is constructed by forming the metatwin M3 of the third embodiment described above on the upper and lower surfaces of the dielectric substrate 30. That is, a dielectric substrate 30 having a thickness of Wb3 is prepared, and the first conductor pattern 31 is formed on the upper surface of the dielectric substrate 30, and the second conductor pattern 32 is formed on the lower surface, so that the first conductor pattern 31 and the second conductor pattern 32 are point-symmetric with respect to the center of the dielectric substrate 30. In this way, the unit element 3 of the third embodiment shown in Figures 20(a), (b), and (c) can be obtained, in which the metatwin M3 of the third embodiment is formed on the upper and lower surfaces of the dielectric substrate 30.

[0051] Returning to Figures 20(a), (b), and (c), the first conductor pattern 31 and the second conductor pattern 32 indicated by dashed lines, which constitute the metatwin M3 formed on the upper and lower surfaces of the dielectric substrate 30, are T-shaped and point-symmetric with respect to the center O of the dielectric substrate 30. The first conductor pattern 31 is composed of three parts in the x direction and one part in the y direction. As shown in Figure 20(b), the three parts in the x direction of the first conductor pattern 31 are composed of parts 31-x-1 and 31-x-3 located on both outer sides and part 31-x-2 located in the center, and the one part in the y direction is composed of part 31-y-1 as shown in Figure 20(a). The second conductor pattern 32 indicated by dashed lines is composed of three parts in the x direction and one part in the y direction. The three parts in the x direction of the second conductor pattern 32 are composed of part 32-x-1 and part 32-x-3 located on both sides as shown in Figure 20(b) and part 32-x-2 located in the center, and the one part in the y direction is composed of part 32-y-1 as shown in Figure 20(a).

[0052] In the unit element 3 of the third embodiment, when viewed through the dielectric substrate 30 from the z direction, the tips of part 31-x-2 of the first conductor pattern 31 and part 32-x-2 of the second conductor pattern 32 overlap. When viewed through the dielectric substrate 30 from the z direction, part 31-x-1, part 31-x-3, and part 31-y-1 of the first conductor pattern 31 and part 32-x-1, part 32-x-3, and part 32-y-1 of the second conductor pattern 32 are positioned on a linear square loop element of a predetermined width. That is, the length Ls3 of the first conductor pattern 31 and the second conductor pattern 32 in the y direction is equal to the length Ls3 from the outer edge of part 31-y-1 of the first conductor pattern 31 to the outer edge of part 32-y-1 of the second conductor pattern 32. To provide additional explanation, as described above, the conductor pattern formed on the dielectric substrate 30 when viewed from the z direction is defined as the basic conductor pattern, and the basic conductor pattern is cut in half along the center line in the y direction to separate it into the first conductor pattern 31 and the second conductor pattern 32, which are line-symmetric and identical in shape. The first conductor pattern 31 is placed on top and the second conductor pattern 32 is placed on the bottom, with their surfaces maintained parallel and separated by a predetermined distance Wb3 in the z direction, which is the direction perpendicular to the surfaces. This constitutes the metatwin M3 of the third embodiment. Note that in the metatwin M3, the tip of the part 31-x-2 of the first conductor pattern 31 and the tip of the part 32-x-2 of the second conductor pattern 32 extend in the x direction.

[0053] The dimensions of each part of the metatwin M3 of the third embodiment are shown in Figure 20(b). The width of the first conductor pattern 31 is length Ls3, the length from the tips of part 31-x-1 and part 31-x-3 to the center of part 31-y-1 is length Lin, and the length from the tip of part 31-x-2 to the center of part 31-y-1 is length Lout, with each part of the first conductor pattern 31 being a linear conductor pattern with a width W. The dimensions of each part of the second conductor pattern 32 are the same because the first conductor pattern 31 and the second conductor pattern 32 have the same shape. That is, the length from the tips of part 32-x-1 and part 32-x-3 to the center of part 32-y-1 is length Lin, and the length from the tip of part 32-x-2 to the center of part 32-y-1 is length Lout, with each part of the second conductor pattern 32 being a linear conductor pattern with a width W. Furthermore, the thickness of the dielectric substrate 30 constituting the unit element 3 of the third embodiment is Wb3 and the relative dielectric constant is εs, as shown in FIG. 20(c), and the first conductor pattern 31 and the second conductor pattern 32 are spaced apart by the thickness Wb3 and are arranged point-symmetrically with respect to the center point O of the dielectric substrate 30.

[0054] Here, an example of the dimensions of each part of the unit element 3 of the third embodiment is expressed in terms of electrical length, with the free space wavelength at an operating frequency of 11.5 GHz being λ (≈26.087 mm). In the first conductor pattern 31 and the second conductor pattern 32, the electrical length of the length Ls3 is approximately 0.307λ, the electrical length of the length Lout is approximately 0.215λ, and the electrical length of the width W is approximately 0.015λ. The length Lin is a set length. The electrical length of the thickness Wb3 of the dielectric substrate 30 is approximately 0.123λ. The dielectric substrate 30 is made of, for example, Teflon (registered trademark), and has a relative dielectric constant εs of approximately 2.6. A relative dielectric constant εs of 2.6 results in a wavelength shortening factor of approximately 0.62.

[0055] The first conductor pattern 31 and the second conductor pattern 32 are formed by applying a metal ink to the surface of the dielectric substrate 30 or by depositing a metal onto the surface to a predetermined thickness and then etching the metal into the desired shape. However, the method for forming the first conductor pattern 31 and the second conductor pattern 32 is not limited to the above-described method, and other methods may be used. Metals with good conductivity, such as gold, silver, copper, and aluminum, are used as the metal material for forming the first conductor pattern 31 and the second conductor pattern 32. Furthermore, the dielectric substrate 30 is preferably made of a material that does not absorb microwaves, such as Teflon (registered trademark). However, the material is not limited to Teflon (registered trademark), and other materials that do not absorb microwaves may also be used.

[0056] In the metatwin M3 of the third embodiment described above, for example, the length Lout is fixed and the length Lin can be set to a predetermined length. In the metatwin M3 of the third embodiment in which the length Lin is set to a predetermined length, it was found that the transmission phase when the set length Lin is long lags behind the transmission phase when the set length Lin is short. Here, Figure 22 shows the amplitude characteristics of the transmitted wave versus the set length Lin for the MetaTwin M3 of the third embodiment of the present invention, when the dimensions of each part are the same as those in the example above and the operating frequency f is 11.5 GHz. In Figure 22, the horizontal axis shows the length Lin from 0 mm to 12 mm as set for the length Lin, and the vertical axis shows the amplitude of the transmitted wave expressed as the absolute value [dB] of the S-parameter S21. Referring to Figure 22, when the length Lin is set to approximately 0.4 mm, the amplitude of the transmitted wave is approximately -1.1 dB. As the length Lin is increased to approximately 2.3 mm, the amplitude of the transmitted wave decreases, and when the length Lin is set to approximately 2.3 mm, the amplitude is approximately -1.5 dB. When the length Lin is set to a value greater than approximately 2.3 mm, the amplitude of the transmitted wave increases, reaching approximately -0.2 dB when the length Lin is set to approximately 4.2 mm. As the length Lin exceeds approximately 4.2 mm, the amplitude of the transmitted wave decreases, reaching approximately -1.0 dB when the length Lin is set to approximately 5.0 mm. As the length Lin is set to a value greater than approximately 5.0 mm, the amplitude of the transmitted wave increases, reaching approximately -0.1 dB when the length Lin is set to approximately 5.6 mm. Furthermore, as the length Lin is increased to approximately 7.6 mm, the amplitude of the transmitted wave decreases, reaching approximately -1.4 dB when the length Lin is set to approximately 7.6 mm. As the length Lin exceeds approximately 7.6 mm, the amplitude of the transmitted wave increases, reaching approximately -0.0 dB when the length Lin is set to approximately 10.8 mm. Thereafter, as the set length Lin becomes longer, the amplitude of the transmitted wave decreases, and when the length Lin is set to approximately 11.6 mm, the amplitude of the transmitted wave is approximately -1.9 dB. Thus, with the MetaTwin M3 of the third embodiment, even when the length Lin is set to a length from approximately 0.4 mm to approximately 11.6 mm, it is possible to transmit almost all of the incident power.

[0057] Next, FIG. 23 shows the transmission phase characteristics for the set length Lin of the MetaTwin M3 according to the third embodiment of the present invention, when the dimensions of each component are the same as those in the example above and the operating frequency f is 11.5 GHz. In FIG. 23, the horizontal axis represents the length Lin, which can be set from 0 mm to 12 mm, and the vertical axis represents the transmission phase, expressed in degrees (deg) of the S-parameter S21. Referring to FIG. 23, when the length Lin is set to approximately 0.4 mm, the transmission phase is approximately 0 degrees. As the length Lin increases to approximately 3.5 mm, the transmission phase is delayed until it reaches approximately -60 degrees. As the length Lin exceeds 3.5 mm, the transmission phase rapidly delays, resulting in a transmission phase of approximately -300 degrees when the length Lin is set to approximately 5.8 mm. As the length Lin exceeds approximately 5.8 mm, the transmission phase gradually delays further, resulting in a transmission phase of approximately -390 degrees when the length Lin is set to approximately 9.5 mm. As the length Lin exceeds 9.5 mm and increases to approximately 11.6 mm, the transmission phase delays further, resulting in a transmission phase of -460 degrees when the length Lin is set to approximately 11.6 mm. Thus, in the MetaTwin M3 of the third embodiment, the transmission phase is approximately 0 degrees when the length Lin is set to approximately 0.4 mm and approximately -460 degrees when the length Lin is set to approximately 11.6 mm. Therefore, increasing the length Lin from approximately 0.4 mm to approximately 11.6 mm can achieve a phase change in the transmission phase of approximately 460 degrees (= 0 degrees - (-460 degrees) = 460 degrees), exceeding 360 degrees. In this case, as described above, most of the incident power can be transmitted.

[0058] <Metasurface plate of the third embodiment> The metatwin M3 of the third embodiment of the present invention can be applied to a metasurface plate in the same manner as the metatwin M1 of the first embodiment. A metasurface plate using the metatwin M3 of the third embodiment is referred to as the metasurface plate of the third embodiment. The metasurface plate of the third embodiment of the present invention is a transmission-type metasurface plate. The metatwin M3 of the third embodiment of the present invention can be periodically arranged on the upper and lower surfaces of a dielectric substrate similar to the dielectric substrate 10, which has a square cross section in the height direction, to form a metasurface plate of the third embodiment (not shown). The metasurface plate of the third embodiment configured in this manner is configured by replacing the metatwin M1 of the first embodiment in the metasurface plate 1-1 of the first embodiment with the metatwin M3 of the third embodiment. That is, the metasurface plate of the third embodiment is composed of a dielectric substrate and a large number of metatwins M3 of the third embodiment periodically arranged on the upper and lower surfaces of the dielectric substrate. In this case, the metatwins M3 of the third embodiment are formed on the dielectric substrate in equal numbers in the x and y directions of the dielectric substrate, similar to the metasurface plate 1-1 of the first embodiment. The metasurface plate of the third embodiment is configured by periodically arranging the unit elements 3 of the third embodiment shown in Figures 20(a), (b), and (c) in the x and y directions, and the unit elements 3 are used as the constituent units that make up the metasurface plate of the third embodiment. In addition, the dielectric substrate in the metasurface plate of the third embodiment is square, with a physical dimension of approximately 110 mm, for example, per side.

[0059] In the metasurface plate of the third embodiment, the length Lin of each metatwin M3 of the multiple metatwins M3 of the third embodiment is set to a predetermined length. When the length Lin is set to a predetermined length corresponding to the incident plane wave, the transmission phase is gradually delayed, resulting in a transmission phase distribution in which the transmitted wave can be deflected in a predetermined direction, for example, by 65 degrees, similar to the refraction of a plane wave in the metasurface plate 1-1 of the first embodiment shown in Figures 7 and 8. When the length Lin is set to a predetermined length corresponding to the incident wave from a local wave source, the transmission phase distribution is such that the transmitted wave is deflected in a predetermined direction, for example, by 65 degrees, similar to the refraction in the case of a local wave source in the metasurface plate 1-1 of the first embodiment shown in Figures 10 and 11. In this case, the radiation pattern when only one metasurface plate of the third embodiment is used is approximately the same as the radiation pattern of the metasurface plate 1-2 of the modified first embodiment shown in Figures 12, 13, and 14. In this way, with the metasurface plate of the third embodiment, it is possible to obtain the desired deflection angle of 0 degrees or more than 60 degrees by using just one metasurface plate of the third embodiment, thereby reducing the overall volume and lowering manufacturing costs. Furthermore, when comparing the frequency characteristics of the gain in the maximum radiation direction when the metasurface plate of the third embodiment of the present invention is used with the frequency characteristics when no metasurface plate is used, the frequency characteristics of the gain in the maximum radiation direction are almost the same as the frequency characteristics of the gain in the maximum radiation direction for the metasurface plate 1-2 of the modified example of the first embodiment shown in Figure 15, and when the metasurface plate of the third embodiment of the present invention is used, a large gain can be obtained in the maximum radiation direction.

[0060] <Unit element of the fourth embodiment having the metatwin of the fourth embodiment> The configuration of a unit element 4 of the fourth embodiment, which includes a metatwin M4 of the fourth embodiment of the present invention, is shown in Figures 24(a), (b), and (c). Figure 24(a) is a perspective view showing the configuration of a unit element 4 of the fourth embodiment, Figure 24(b) is a top view showing the configuration of a unit element 4 of the fourth embodiment, and Figure 24(c) is a side view showing the configuration of a unit element 4 of the fourth embodiment. Also, Figure 25 is a perspective view illustrating the configuration of a metatwin M4 of the fourth embodiment of the present invention. As shown in Figures 24(a), (b), and (c), the unit element 4 of the fourth embodiment is composed of a dielectric substrate 40 and the metatwin M4 of the fourth embodiment formed on the upper and lower surfaces of the dielectric substrate 40. The metatwin M4 of the fourth embodiment is composed of a first conductor pattern 41 formed on the upper surface of the dielectric substrate 40 and a second conductor pattern 42 formed on the lower surface of the dielectric substrate 40. The first conductor pattern 41 and the second conductor pattern 42 have the same shape and are shaped point-symmetrically with respect to the center O of the dielectric substrate 40 shown in Figure 24(c).

[0061] The metatwin M4 of the fourth embodiment will be described with reference to Fig. 25. Fig. 25 shows the configuration of the metatwin M4 of the fourth embodiment, in which a first conductor pattern 41 is disposed on top, and a second conductor pattern 42 that is point-symmetrical to and has the same shape as the first conductor pattern 41 is disposed below, with the two patterns spaced apart in the z direction by a predetermined distance Wb4. This forms a metatwin M4 in which the first conductor pattern 41 and the second conductor pattern 42 are shaped to be point-symmetrical with respect to the center of the space formed by the spaced-apart first conductor pattern 41 and second conductor pattern 42.

[0062] When the metatwin M4 of the fourth embodiment is viewed from the z direction, the first conductor pattern 41 and the second conductor pattern 42 form a double loop element, as shown in FIG. 24(b), consisting of a linear square-shaped outer loop of a predetermined width and a linear square-shaped inner loop of a predetermined width rotated approximately 45 degrees, which are concentric. This double loop element is the basic conductor pattern. In the double loop element constituting the basic conductor pattern of the metatwin M4, the diagonal corners in the x direction of the inner loop and the center of the outer loop are connected by connecting pieces. The double loop element serving as the basic conductor pattern is cut in half along the center line in the y direction to separate the first conductor pattern 41 and the second conductor pattern 42, which are line-symmetric and have the same shape. The first conductor pattern 41 is placed on top and the second conductor pattern 42 is placed below, with their surfaces maintained parallel and separated by a predetermined distance Wb4 in the z direction, which is the direction perpendicular to the surfaces. This forms the metatwin M4 of the fourth embodiment. The unit element 4 of the fourth embodiment is constructed by forming the metatwin M4 of the fourth embodiment configured as described above on the upper and lower surfaces of a dielectric substrate 40. That is, a dielectric substrate 40 having a thickness of Wb4 is prepared, and the first conductor pattern 41 is formed on the upper surface of the dielectric substrate 40, and the second conductor pattern 42 is formed on the lower surface, so that the first conductor pattern 41 and the second conductor pattern 42 are point-symmetric with respect to the center of the dielectric substrate 40. In this way, the unit element 4 of the fourth embodiment shown in Figures 24(a), (b), and (c) can be obtained, in which the metatwin M4 of the fourth embodiment is formed on the upper and lower surfaces of the dielectric substrate 40.

[0063] 24(a), (b), and (c), the first conductor pattern 41 and the second conductor pattern 42 indicated by the dashed lines, which constitute the metatwin M4 formed on the upper and lower surfaces of the dielectric substrate 40, have the same shape, with a Y-shaped conductor pattern disposed inside the U-shaped conductor pattern, and are arranged point-symmetrically with respect to the center O of the dielectric substrate 40. The first conductor pattern 41 is composed of three parts in the x-direction and three parts in the y-direction and tilted y-direction. As shown in FIG. 24(b), the three parts in the x-direction of the first conductor pattern 41 are composed of part 41-x-1 and part 41-x-3 located on both outer sides and part 41-x-2 located in the center and connected to the Y-shaped conductor pattern, while the three parts in the y-direction and tilted y-direction are composed of part 41-y-1 and part 41-y-2 and part 41-y-3 that form the Y-shaped conductor pattern, as shown in FIG. 24(a). The second conductor pattern 42, indicated by dashed lines, is composed of three parts in the x direction and three parts in the y direction and tilted y direction. As shown in Fig. 24(b), the three parts in the x direction of the second conductor pattern 42 are composed of part 42-x-1 and part 42-x-3 located on both outer sides and part 42-x-2 located in the center and connected to the Y-shaped conductor pattern, and the three parts in the y direction and tilted y direction are composed of part 42-y-1 and part 42-y-2 and part 42-y-3 that form the Y-shaped conductor pattern, as shown in Fig. 24(a).

[0064] 24(b), when the dielectric substrate 40 is viewed from the z direction, the tips of parts 41-x-1 and 41-x-3 of the first conductor pattern 41 and parts 42-x-1 and 42-x-3 of the second conductor pattern 42 overlap, and the tips of parts 41-y-2 and 41-y-3 of the first conductor pattern 41 and parts 42-y-2 and 42-y-3 of the second conductor pattern 42 overlap. Furthermore, when the dielectric substrate 40 is viewed from the z direction, parts 41-x-1, 41-x-3, and 41-y-1 of the first conductor pattern 41 and parts 42-x-1, 42-x-3, and 42-y-1 of the second conductor pattern 42 form a linear square-shaped outer loop with a predetermined width, as shown in FIG. As a result, the length Ls4 in the y direction of the first conductor pattern 41 and the second conductor pattern 42 is equal to the length Ls4 from the outer edge of part 41-y-1 of the first conductor pattern 41 to the outer edge of part 42-y-1 of the second conductor pattern 42. Furthermore, when the dielectric substrate 40 is seen through from the z direction, as shown in Fig. 24(b), the parts 41-y-2 and 41-y-3 of the first conductor pattern 41 and the parts 42-y-2, 42-y-3 and 42-y-1 of the second conductor pattern 42 form a linear inner loop having a predetermined width and a square shape rotated by approximately 45 degrees.

[0065] 24(b) shows the dimensions of each part of the metatwin M4 of the fourth embodiment. The width of the first conductor pattern 41 is length Ls4, the length from the tips of parts 41-x-1 and 41-x-3 to the center of part 41-y-1 is length Lout, and the length from the tips of parts 41-y-2 and 41-y-3 to the center of part 41-y-1 is length Lin, and each part of the first conductor pattern 41 is a linear conductor pattern with width W. The dimensions of each part of the second conductor pattern 42 are the same because the first conductor pattern 41 and the second conductor pattern 42 have the same shape. That is, the length from the tips of parts 42-x-1 and 42-x-3 to the center of part 42-y-1 is Lout, and the length from the tips of parts 42-y-2 and 42-y-3 to the center of part 42-y-1 is Lin, and each part in the second conductor pattern 42 is a linear conductor pattern of width W. Furthermore, the thickness of the dielectric substrate 40 constituting the unit element 4 of the fourth embodiment is Wb4 and has a relative dielectric constant εs, as shown in FIG. 24(c), and the first conductor pattern 41 and the second conductor pattern 42 are spaced apart by the thickness Wb4 and are arranged point-symmetrically with respect to the center point O of the dielectric substrate 40.

[0066] Here, an example of the dimensions of each part of the unit element 4 of the fourth embodiment is expressed in terms of electrical length, with the free space wavelength at an operating frequency of 11.5 GHz being λ (≈26.087 mm). In the first conductor pattern 41 and the second conductor pattern 42, the electrical length of the length Ls4 is approximately 0.307λ, the electrical length of the length Lout is approximately 0.360λ, and the electrical length of the width W is approximately 0.015λ. The length Lin is a set length. The electrical length of the thickness Wb4 of the dielectric substrate 40 is approximately 0.123λ. The dielectric substrate 40 is made of, for example, Teflon (registered trademark), and has a relative dielectric constant εs of approximately 2.6. When the relative dielectric constant εs is 2.6, the wavelength shortening factor is approximately 0.62.

[0067] The first conductor pattern 41 and the second conductor pattern 42 are formed by applying a metal ink to the surface of the dielectric substrate 40 or by depositing a metal onto the surface to a predetermined thickness and then etching the metal into the desired shape. However, the method for forming the first conductor pattern 41 and the second conductor pattern 42 is not limited to the above-described method, and other methods may be used. Metals with good conductivity, such as gold, silver, copper, and aluminum, are used as the metal material for forming the first conductor pattern 41 and the second conductor pattern 42. Furthermore, the dielectric substrate 40 is preferably made of a material that does not absorb microwaves, such as Teflon (registered trademark). However, the material is not limited to Teflon (registered trademark), and other materials that do not absorb microwaves may also be used.

[0068] In the metatwin M4 of the fourth embodiment described above, for example, the length Lout is fixed and the length Lin can be set to a predetermined length. In the metatwin M4 of the fourth embodiment in which the length Lin is set to a predetermined length, it was found that the transmission phase when the set length Lin is long lags behind the transmission phase when the set length Lin is short. Here, Fig. 26 shows the amplitude characteristics of the transmitted wave versus the set length Lin for the MetaTwin M4 of the fourth embodiment of the present invention, when the dimensions of each part are the same as those in the example above and the operating frequency f is 11.5 GHz. In Fig. 26, the horizontal axis shows the length Lin set to 0 mm to 9 mm, and the vertical axis shows the amplitude of the transmitted wave expressed as the absolute value [dB] of the S-parameter S21. Referring to Fig. 26, when the length Lin is set to approximately 0.0 mm, the amplitude of the transmitted wave is approximately -1.1 dB. As the length Lin is increased to approximately 1.3 mm, the amplitude of the transmitted wave increases, and when the length Lin is set to approximately 1.3 mm, the amplitude is approximately -0.1 dB. When the length Lin is set to a value greater than approximately 1.3 mm, the amplitude of the transmitted wave decreases, reaching approximately -0.7 dB when the length Lin is set to approximately 1.6 mm. As the length Lin exceeds approximately 1.6 mm, the amplitude of the transmitted wave increases, reaching approximately -0.1 dB when the length Lin is set to approximately 1.9 mm. As the length Lin is set to a value greater than approximately 1.9 mm, the amplitude of the transmitted wave decreases, reaching approximately -1.3 dB when the length Lin is set to approximately 3.0 mm to approximately 4.4 mm. Furthermore, as the length Lin is increased to approximately 7.9 mm, the amplitude of the transmitted wave increases, reaching approximately 0.0 dB when the length Lin is set to approximately 7.9 mm. As the length Lin exceeds approximately 7.9 mm, the amplitude of the transmitted wave decreases, reaching approximately -1.0 dB when the length Lin is set to approximately 8.5 mm. In this way, the MetaTwin M4 of the fourth embodiment can transmit almost all of the incident power even when the length Lin is set to a value between about 0.0 mm and about 8.5 mm.

[0069] Next, FIG. 27 shows the transmission phase characteristics for the set length Lin of the MetaTwin M4 according to the fourth embodiment of the present invention, when the dimensions of each component are the same as those in the example above and the operating frequency f is 11.5 GHz. In FIG. 27, the horizontal axis represents the length Lin, which can be set from 0 mm to 9 mm, and the vertical axis represents the transmission phase, expressed in degrees (deg) of the S-parameter S21. Referring to FIG. 27, when the length Lin is set to approximately 0.0 mm, the transmission phase is approximately 175 degrees. As the length Lin increases to approximately 1.0 mm, the transmission phase gradually lags, and when the length Lin is set to approximately 1.0 mm, the transmission phase is approximately 150 degrees. As the length Lin exceeds 1.0 mm, the transmission phase rapidly lags, resulting in a transmission phase of approximately -105 degrees when the length Lin is set to approximately 2.2 mm. As the length Lin exceeds approximately 2.2 mm, the transmission phase gradually becomes more delayed, resulting in a transmission phase of approximately -170 degrees when the length Lin is set to approximately 6.5 mm. As the length Lin exceeds 6.5 mm and increases to approximately 8.5 mm, the transmission phase becomes more delayed, resulting in a transmission phase of -225 degrees when the length Lin is set to approximately 8.5 mm. Thus, in the MetaTwin M4 of the fourth embodiment, the transmission phase is approximately 175 degrees when the length Lin is set to approximately 0.0 mm and approximately -225 degrees when the length Lin is set to approximately 8.5 mm. Therefore, as the length Lin is increased from approximately 0.0 mm to approximately 8.5 mm, a phase change in the transmission phase of approximately 400 degrees (= 175 degrees - (-225 degrees) = 400 degrees), which exceeds 360 degrees, can be obtained. In this case, as described above, almost all of the incident power can be transmitted.

[0070] <Fourth Example of Metasurface Plate> The metatwin M4 of the fourth embodiment of the present invention can be applied to a metasurface plate in the same manner as the metatwin M1 of the first embodiment. A metasurface plate using the metatwin M4 of the fourth embodiment is referred to as the metasurface plate of the fourth embodiment. The metasurface plate of the fourth embodiment of the present invention is a transmission-type metasurface plate. The metatwin M4 of the fourth embodiment of the present invention can be periodically arranged on the upper and lower surfaces of a dielectric substrate similar to the dielectric substrate 10, which has a square cross section in the height direction, to form a metasurface plate of the fourth embodiment (not shown). The metasurface plate of the fourth embodiment configured in this manner is configured by replacing the metatwin M1 of the first embodiment in the metasurface plate 1-1 of the first embodiment with the metatwin M4 of the fourth embodiment. That is, the metasurface plate of the fourth embodiment is composed of a dielectric substrate and a large number of metatwins M4 of the fourth embodiment periodically arranged on the upper and lower surfaces of the dielectric substrate. In this case, the metatwins M4 of the fourth embodiment are formed on the dielectric substrate in equal numbers in the x and y directions of the dielectric substrate, similar to the metasurface plate 1-1 of the first embodiment. The metasurface plate of the fourth embodiment is configured by periodically arranging the unit elements 4 of the fourth embodiment shown in Figures 24(a), (b), and (c) in the x and y directions, and the unit elements 4 are used as the constituent units that make up the metasurface plate of the fourth embodiment. In addition, the dielectric substrate in the metasurface plate of the fourth embodiment is square, with a physical dimension of approximately 110 mm, for example, per side.

[0071] In the metasurface plate of the fourth embodiment, the length Lin of each of the multiple metatwins M4 of the fourth embodiment is set to a predetermined length. When the length Lin is set to a predetermined length corresponding to the incident plane wave, the transmission phase is gradually delayed, resulting in a transmission phase distribution in which the transmitted wave can be deflected in a predetermined direction, for example, by 65 degrees, similar to the refraction of a plane wave in the metasurface plate 1-1 of the first embodiment shown in Figures 7 and 8. When the length Lin is set to a predetermined length corresponding to the incident wave from a local wave source, the transmission phase distribution is such that the transmitted wave is deflected in a predetermined direction, for example, by 65 degrees, similar to the refraction in the case of a local wave source in the metasurface plate 1-1 of the first embodiment shown in Figures 10 and 11. In this case, the radiation pattern when only one metasurface plate of the fourth embodiment is used is approximately the same as the radiation pattern of the metasurface plate 1-2 of the modified first embodiment shown in Figures 12, 13, and 14. In this way, with the metasurface plate of the fourth embodiment, it is possible to obtain the desired deflection angle of 0 degrees or more than 60 degrees by using just one metasurface plate of the fourth embodiment, thereby reducing the overall volume and lowering manufacturing costs. Furthermore, when comparing the frequency characteristics of gain in the maximum radiation direction when using the metasurface plate of the fourth embodiment of the present invention with when not using a metasurface plate, the frequency characteristics of gain in the maximum radiation direction are almost the same as the frequency characteristics of gain in the maximum radiation direction for the metasurface plate 1-2 of the modified example of the first embodiment shown in Figure 15, and when using the metasurface plate of the fourth embodiment of the present invention, a large gain can be obtained in the maximum radiation direction. [Industrial Applicability]

[0072] In the metatwin of the embodiment of the present invention described above, one example of dimensions has been given. However, the dimensions of each part of the metatwin of the embodiment are not limited to the above example. Even if the dimensions are set to half or twice the dimensions given in the example, the same effects as those described above can be obtained. Furthermore, in the metatwin of the embodiment of the present invention, the length Lout is fixed and the length Lin is a set length. However, this is not limited to this, and the length Lout may be a set length. In this case, if the length Lout is a set length in the metatwin of the embodiment of the present invention, the transmission phase of the metatwin of the embodiment will be a transmission phase corresponding to the length Lout. Therefore, the metatwin of the embodiment of the present invention may be modified such that the length Lout is a set length and the length Lin is a fixed length, or such that the lengths Lout and Lin are set lengths. Even in this modification, a large phase change in the transmission phase can be obtained, similar to the effects that can be achieved by the metatwin of the embodiment of the present invention described above. Depending on the length Lin or length Lout set, the first conductor pattern and the second conductor pattern may be metatwins in which at least one tip of each pattern overlaps, or in which the tips do not overlap. Furthermore, in the metatwin of the embodiment of the present invention described above, the shape of the loop is square, but this is not limited to this and the shape may be rectangular, polygonal, circular, elliptical, or the like.

[0073] The vertical and horizontal dimensions of the metasurface plate of the embodiment of the present invention described above are not limited to the above-mentioned example dimensions, and any dimensions may be used as long as the desired pattern of the radiation wave is obtained. Also, in the metasurface plate of the embodiment of the present invention, the shape of the dielectric substrate is square, but this is not limited to this and it may be rectangular, polygonal, circular, elliptical, or other shapes. In addition, in the metasurface plate of the embodiment of the present invention described above, an electronic element, such as a varicap, that adjusts the transmission phase of each metatwin of the embodiment of the present invention formed on the metasurface plate may be attached to the surface of the metasurface plate. In this way, by attaching an electronic element that adjusts the transmission phase of each metatwin to the metasurface plate of the embodiment of the present invention, it becomes possible to adjust the deflection angle and pattern of the transmitted wave. Furthermore, when the metasurface plate according to the embodiment of the present invention described above is placed on a ground plate provided with a local wave source such as a patch antenna, the distance d between the ground plate and the metasurface plate according to the embodiment can be an integer multiple of approximately 0.25λ, where λ is the free space wavelength of the operating frequency f. However, the distance d is not limited to these distances and can be other distances. Furthermore, in the metasurface plate of the embodiment of the present invention described above, the transmitted wave is deflected and radiated in one predetermined direction. However, the transmitted wave can also be deflected and radiated in two or four directions. When the transmitted wave is deflected and radiated in two directions, for example, the x direction and the -x direction, a transmission phase distribution in which the transmission phase of each metatwin gradually delays from the center line of the y direction toward the x direction and from the center line of the y direction toward the -x direction, as in the case shown in Figure 33, can be used to obtain a radiation pattern in which the transmitted wave is radiated in two directions, the x direction and the -x direction, as in the case shown in Figure 34. Furthermore, when the transmitted wave is deflected and radiated in four directions, for example, the ±x direction and the ±y direction, a transmission phase distribution in which the transmission phase of each metatwin gradually delays from the center toward the ±x direction and from the center toward the ±y direction, as in the case shown in Figure 35, can be used to obtain a radiation pattern in which the transmitted wave is radiated in four directions, the ±x direction and the ±y direction. Furthermore, in the metasurface plate of the embodiment of the present invention, whether the incident wave is incident from the bottom surface or the top surface of the metasurface plate of the embodiment, the same polarized transmitted wave is radiated. In other words, since the metasurface plate of the embodiment of the present invention is reversible, it can be used as a metasurface plate that can radiate in a desired direction when transmitting and can receive from a desired direction. [Explanation of symbols]

[0074] 1,2,3,4 Unit element, 1-1,1-2 Metasurface plate, 10 Dielectric substrate, 11 First conductor pattern, 12 Second conductor pattern, 20 Dielectric substrate, 21 First conductor pattern, 21a, 21b First conductor pattern, 22 Second conductor pattern, 22a, 22b Second conductor pattern, 30 Dielectric substrate, 31 First conductor pattern, 32 Second conductor pattern, 40 Dielectric substrate, 41 First conductor pattern, 42 Second conductor pattern, 110, 110b, 110c Metasurface plate, 111, 111a, 111b, 111c Unit element, 112, 112a, 112b, 112c Loop element, 120 Dielectric substrate, 130 Patch antenna, 131 Antenna substrate, 140 Ground plate, AN Patch antenna, BP Antenna substrate, G Ground plate, LP1 Double loop element, LPin Inner loop, LPout Outer loop, M1, M2, M3, M4 Meta Twin

Claims

1. a dielectric substrate; a double-loop basic conductor pattern is formed by a rectangular outer loop formed by lines of a predetermined width and a rectangular inner loop formed by lines of a predetermined width concentrically arranged with the outer loop, and a metatwin is provided which is formed by a first conductor pattern and a second conductor pattern which are formed by cutting half of the basic conductor pattern and have an axisymmetric double U-shape, In the metatwin, the first conductor pattern and the second conductor pattern are each composed of a first U-shaped part formed by the outer loop that is half cut off, and a second U-shaped part formed by the inner loop that is half cut off, the first conductor pattern is formed on one surface of the dielectric substrate, and the second conductor pattern, which has the same shape as the first conductor pattern, is formed point-symmetrically with the first conductor pattern on the other surface of the dielectric substrate, and tips of the first and second conductor patterns, which are double U-shaped, face each other; the first conductor pattern and the second conductor pattern are formed on one surface and the other surface of the dielectric substrate, respectively, spaced apart by a predetermined distance in a direction perpendicular to the surfaces while maintaining the surfaces parallel to each other; A unit element characterized in that, in the first conductor pattern and the second conductor pattern, tips of the first U-shaped parts overlap when viewed from a vertical direction, and the length of the second U-shaped part is settable, or, in the first conductor pattern and the second conductor pattern, tips of the second U-shaped parts overlap when viewed from a vertical direction, and the length of the first U-shaped part is settable.

2. The unit element according to claim 1, characterized in that a connecting piece of a predetermined width is formed in each of the first conductor pattern and the second conductor pattern, connecting between the center of the first U-shaped part and the center of the second U-shaped part.

3. The unit element according to claim 2, wherein the connecting piece has a groove formed in the center thereof, and the connecting piece is cut along the groove.

4. a dielectric substrate; a metatwin including a first conductor pattern having a T-shape made up of one horizontal part and three vertical parts each made up of a line of a predetermined width, and a second conductor pattern having the same shape as the first conductor pattern and arranged point-symmetrically; In the metatwin, the first conductor pattern and the second conductor pattern have three vertical parts located on both sides and in the center of one horizontal part, the first conductor pattern is formed on one surface of the dielectric substrate, and the second conductor pattern having the same shape as the first conductor pattern is formed on the other surface of the dielectric substrate in point symmetry with the first conductor pattern, with tips of the T-shaped first conductor pattern and the T-shaped second conductor pattern facing each other; the first conductor pattern and the second conductor pattern are formed on one surface and the other surface of the dielectric substrate, respectively, spaced apart by a predetermined distance in a direction perpendicular to the surfaces while maintaining the surfaces parallel to each other; A unit element characterized in that, in the first conductor pattern and the second conductor pattern, the tips of the vertical parts located in the center of one of the horizontal parts overlap when viewed from a vertical direction, and the lengths of the two vertical parts located on both sides of one of the horizontal parts can be set.

5. a dielectric substrate; a double-loop basic conductor pattern consisting of a rectangular outer loop formed of a line shape of a predetermined width and a rectangular inner loop formed of a line shape of a predetermined width that is arranged concentrically with the outer loop and rotated approximately 45 degrees with respect to the outer loop; and a metatwin consisting of a first conductor pattern and a second conductor pattern that are line-symmetric double loops formed by half-cutting the basic conductor pattern; In the metatwin, the first conductor pattern and the second conductor pattern are each composed of a U-shaped part formed by half-cutting the outer loop, a Y-shaped part formed by half-cutting the inner loop, and a connecting piece connecting a center of the U-shaped part to a center of the Y-shaped part, the first conductor pattern is formed on one surface of the dielectric substrate, and the second conductor pattern having the same shape as the first conductor pattern is formed on the other surface of the dielectric substrate in point symmetry with the first conductor pattern, and tips of the U-shaped part and the Y-shaped part of the first conductor pattern and the second conductor pattern face each other, the first conductor pattern and the second conductor pattern are formed on one surface and the other surface of the dielectric substrate, respectively, spaced apart by a predetermined distance in a direction perpendicular to the surfaces while maintaining the surfaces parallel to each other; A unit element characterized in that, in the first conductor pattern and the second conductor pattern, the tips of the U-shaped parts overlap when viewed from a vertical direction, and the length of the Y-shaped part is settable.

6. a second dielectric substrate; a metatwin formed in the unit element according to any one of claims 1 to 5 and periodically arranged in the x direction and the y direction of the second dielectric substrate; the first conductor patterns in the metatwin are periodically arranged on the upper surface of the second dielectric substrate, the second conductor patterns in the metatwin are periodically arranged on the lower surface of the second dielectric substrate and are formed to correspond to the first conductor patterns; A metasurface plate characterized in that the dielectric substrate provided in the unit element described in any one of claims 1 to 5 is replaced with the second dielectric substrate.

7. The metasurface plate described in claim 6, characterized in that in the metatwins formed by being periodically arranged in the x and y directions of the second dielectric substrate, the transmission phase of each metatwin is set to a predetermined transmission phase, thereby forming a distribution of predetermined transmission phases.

8. The metasurface plate described in claim 7, characterized in that the transmission phase in each metatwin is a distribution of transmission phases that gradually delay in a predetermined direction, and an incident wave incident from one surface of the second dielectric substrate is radiated as a transmission wave deflected in a predetermined direction.

9. The metasurface plate described in claim 7, characterized in that the phase of the incident wave radiated from a local wave source and incident from one surface of the second dielectric substrate is set to a phase corresponding to the distance between the wave source and the incident position on the second dielectric substrate, and the transmission phase in each of the metatwins is set according to the distance.

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