Composite resonator and radio wave control plate

Abstract

This composite resonator includes a resonant structure including: a dielectric layer; a resonator extending over a first surface provided on the dielectric layer; and a reference conductor facing the resonator via the dielectric layer. The resonator has a curve on at least a part of the side surface.

Description

Composite resonator and radio wave control board

[0001] The present disclosure relates to a composite resonator and a radio wave control plate.

[0002] There are known techniques for controlling electromagnetic waves without using a dielectric lens. For example, Patent Document 1 describes a technique for refracting radio waves by changing the parameters of each element in a structure in which resonator elements are arranged.

[0003] JP 2015-231182 A

[0004] The composite resonator of the present disclosure comprises a resonant structure including a dielectric layer, a resonator extending over a first surface provided on the dielectric layer, and a reference conductor facing the resonator via the dielectric layer, and the resonator has a curve on at least a portion of a side surface.

[0005] The radio wave control plate of the present disclosure includes a plurality of composite resonators of the present disclosure, and the plurality of composite resonators are arranged on a first surface.

[0006] FIG. 1 is a diagram for explaining an overview of a radio wave control plate. FIG. 2 is a diagram showing an example of the configuration of a unit structure according to the first embodiment. FIG. 3 is a diagram showing an example of the configuration of a resonator according to a comparative example. FIG. 4 is a diagram showing an example of the configuration of a resonator according to a first example of the first embodiment. FIG. 5 is a diagram showing an example of the configuration of a resonator according to a second example of the first embodiment. FIG. 6 is a diagram showing an example of the configuration of a resonator according to a third example of the first embodiment. FIG. 7 is a diagram showing an example of the configuration of a resonator according to a fourth example of the first embodiment. FIG. 8 is a diagram for explaining the frequency characteristics of a unit structure according to a comparative example. FIG. 9 is a diagram for explaining the frequency characteristics of a unit structure according to the first embodiment. FIG. 10 is a diagram for explaining the reception characteristics of a radio wave control plate according to a comparative example. FIG. 11 is a diagram for explaining the reception characteristics of a radio wave control plate according to the first embodiment. FIG. 12 is a diagram showing an example of the configuration of a resonator according to a second embodiment. FIG. 13 is a diagram showing an example of the configuration of a unit structure according to a third embodiment. FIG. 14 is a diagram for explaining the phase change amount of a unit structure according to a comparative example. FIG. 15 is a diagram for explaining the phase change amount of a unit structure according to the third embodiment.

[0007] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to this embodiment, and in the following embodiments, the same components are designated by the same reference numerals, and redundant explanations will be omitted.

[0008] In the following description, an XYZ Cartesian coordinate system is set, and the positional relationship of each part will be described with reference to this XYZ Cartesian coordinate system. The direction parallel to the X axis in a horizontal plane is defined as the X-axis direction, the direction parallel to the Y axis in the horizontal plane perpendicular to the X axis is defined as the Y-axis direction, and the direction parallel to the Z axis perpendicular to the horizontal plane is defined as the Z-axis direction. Furthermore, the plane including the X axis and Y axis will be referred to as the XY plane as appropriate, the plane including the X axis and Z axis will be referred to as the XZ plane as appropriate, and the plane including the Y axis and Z axis will be referred to as the YZ plane as appropriate. The XY plane is parallel to the horizontal plane. The XY plane, XZ plane, and YZ plane are perpendicular to each other.

[0009] [First embodiment] (Radio wave control plate) An outline of the radio wave control plate will be described with reference to Fig. 1. Fig. 1 is a diagram for explaining the outline of the radio wave control plate.

[0010] The radio wave control board 1 is a plate-shaped member configured to be able to reflect or transmit (refract) radio waves transmitted from a base station. For example, when receiving radio waves transmitted from a base station, the radio wave control board 1 is configured to reflect or refract the radio waves at a predetermined angle. The radio wave control board 1 can be configured, for example, from a metamaterial that changes the phase of the incident wave.

[0011] 1, radio wave control board 1 may include, for example, substrate 2 and unit structures 10a, 10b, 10c, and 10d. When there is no need to distinguish between unit structures 10a to 10d, they will be collectively referred to as unit structures 10.

[0012] The unit structures 10a, 10b, 10c, and 10d may be formed on a substrate 2. The substrate 2 may be, for example, a dielectric substrate made of a dielectric material. The substrate 2 may have, for example, but is not limited to, a rectangular shape. The unit structures 10a, 10b, 10c, and 10d may be arranged two-dimensionally.

[0013] In the radio wave control board 1, a plurality of unit structures 10a are arranged along the X-axis direction on one tier. A plurality of unit structures 10b are arranged along the X-axis direction on the tier above the tier on which unit structures 10a are arranged. A plurality of unit structures 10c are arranged along the X-axis direction on the tier above the tier on which unit structures 10b are arranged. A plurality of unit structures 10d are arranged along the X-axis direction on the tier above the tier on which unit structures 10c are installed. In the example shown in FIG. 1 , unit structures 10a, unit structures 10b, unit structures 10c, and unit structures 10d are arranged periodically along the Y-axis direction.

[0014] Unit structure 10a, unit structure 10b, unit structure 10c, and unit structure 10d are all different in size. In the example shown in Fig. 1, unit structure 10a is the largest, followed by unit structure 10b, unit structure 10c, and unit structure 10d in order of size. That is, radio wave control board 1 has a structure in which a plurality of unit structures 10 of different sizes are periodically arranged.

[0015] The unit structures 10a to 10d may each have a different amount of phase change in the received radio waves. That is, the unit structures 10a to 10d are periodically arranged so as to have a gradient in the amount of phase change. The unit structures 10a to 10d each have a rectangular shape, but are not limited to this. By changing the size and shape of the unit structures 10a to 10d, the frequency band and amount of phase change of the radio waves to be reflected or refracted can be adjusted.

[0016] [Unit Structure] A configuration example of the unit structure according to the first embodiment will be described with reference to Fig. 2. Fig. 2 is a diagram showing a configuration example of the unit structure according to the first embodiment.

[0017] 2, the unit structure 10 includes a resonator 11, a reference conductor 21, and a dielectric layer 31. The unit structure 10 is also called a composite resonator.

[0018] The resonator 11 is a resonator made of a conductive material (metal material). The resonator 11 has, for example, a rectangular shape when viewed from the Z-axis direction, and an isosceles trapezoid shape with inwardly recessed left and right sides when viewed from the Y-axis direction, but is not limited to this. The resonator 11 is formed on the upper surface of the unit structure 10.

[0019] The reference conductor 21 is a ground conductor made of a conductive material and is formed on the lower surface of the unit feature 10. For example, the reference conductor 21 is formed over the entire lower surface of the unit feature 10.

[0020] The dielectric layer 31 is a dielectric substrate located between the resonator 11 and the reference conductor 21. That is, the resonator 11 is formed on the upper surface of the dielectric layer 31, and the reference conductor 21 is formed on the lower surface of the dielectric layer 31.

[0021] [Resonator] (Comparative Example) A configuration example of a resonator according to a comparative example will be described with reference to Fig. 3. Fig. 3 is a diagram showing a configuration example of a resonator according to a comparative example.

[0022] 3, the resonator 11a according to the comparative example is formed in a rectangular shape. The resonator 11a has an upper side 111a, a lower side 112a, a left side 113a, and a right side 114a. The upper side 111a, the lower side 112a, the left side 113a, and the right side 114a are all straight lines. The lengths of each part of the resonator 11a in the X-axis direction and the Y-axis direction are the same.

[0023] (First Example of First Embodiment) A configuration example of a resonator according to a first example of the first embodiment will be described with reference to Fig. 4. Fig. 4 is a diagram showing a configuration example of a resonator according to the first example of the first embodiment.

[0024] As shown in FIG. 4 , the resonator 11 has an upper side 111, a lower side 112, a left side 113, and a right side 114. The upper side 111 is curved. The lower side 112, the left side 113, and the right side 114 are straight. That is, the resonator 11 has a rectangular shape in which one side is curved. Specifically, the upper side 111 has a curved shape that is concave inward of the rectangle when viewed from the Z-axis direction. Therefore, the length in the Y-axis direction varies at each point on the resonator 11. Therefore, the resonator 11 may have different resonant frequencies at each point. In other words, the resonator 11 has multiple resonant frequencies. As a result, the resonator 11 can transmit or reflect a wider frequency band of radio waves than the resonator 11a shown in FIG. 3 .

[0025] (Second Example of First Embodiment) A configuration example of a resonator according to a second example of the first embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram showing a configuration example of a resonator according to the second example of the first embodiment.

[0026] As shown in FIG. 5 , the resonator 11A has an upper side 111A, a lower side 112A, a left side 113A, and a right side 114A. The upper side 111A is curved. The lower side 112A, the left side 113A, and the right side 114A are straight. That is, the resonator 11A has a rectangular shape with one side curved. Specifically, the upper side 111A has a curved shape that bulges outward from the rectangle when viewed from the Z-axis direction. Therefore, the length of each point on the resonator 11A in the Y-axis direction is different. In other words, the resonator 11A has multiple resonant frequencies. Therefore, the resonant frequencies of the resonator 11A can be different at each point. As a result, the resonator 11A can transmit or reflect a wider frequency band of radio waves than the resonator 11a shown in FIG. 3 .

[0027] (Third Example of First Embodiment) A configuration example of a resonator according to a third example of the first embodiment will be described with reference to Fig. 6. Fig. 6 is a diagram showing a configuration example of a resonator according to the third example of the first embodiment.

[0028] As shown in FIG. 6 , the resonator 11B has an upper side 111B, a lower side 112B, a left side 113B, and a right side 114B. The upper side 111B, the lower side 112B, the left side 113B, and the right side 114B are formed in a wavy shape when viewed from the Z-axis direction. That is, all of the sides of the resonator 11B are formed in a curved shape. Therefore, the length in the Y-axis direction varies at each point on the resonator 11B. In other words, the resonator 11B has multiple resonant frequencies. Therefore, the resonant frequencies of the resonator 11B can vary at each point. As a result, the resonator 11B can transmit or reflect a wider frequency band of radio waves than the resonator 11a shown in FIG. 3 .

[0029] (Fourth Example of First Embodiment) A configuration example of a resonator according to a fourth example of the first embodiment will be described with reference to Fig. 7. Fig. 7 is a diagram showing a configuration example of a resonator according to the fourth example of the first embodiment.

[0030] As shown in FIG. 7 , the resonator 11C has an upper side 111C, a lower side 112C, a left side 113C, and a right side 114C. The upper side 111C, the lower side 112C, the left side 113C, and the right side 114C are curved. Specifically, the upper side 111C, the lower side 112C, the left side 113C, and the right side 114C each have a curved shape that is concave inward of the rectangle when viewed in the Z-axis direction. That is, all of the sides of the resonator 11C are curved. Therefore, the length of each point of the resonator 11C in the Y-axis direction is different. In other words, the resonator 11C has multiple resonant frequencies. Therefore, the resonant frequencies of the resonator 11C can be different at each point. As a result, the resonator 11C can transmit or reflect a wider frequency band of radio waves than the resonator 11a shown in FIG. 3 .

[0031] In the first embodiment, for example, it is sufficient that at least one side of the rectangular resonator is curved. In other words, in the first embodiment, it is sufficient that a part of the rectangular resonator is curved. The shape of the resonator is not limited to a rectangle, and may be another polygon. For example, the shape of the resonator may be another even-numbered polygon other than a rectangle.

[0032] (Frequency Characteristics) The frequency characteristics of the unit structure will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a diagram for explaining the frequency characteristics of the unit structure according to the comparative example. Fig. 9 is a diagram for explaining the frequency characteristics of the unit structure according to the first embodiment.

[0033] The unit structure according to the comparative example has a structure in which the resonator 11 of the unit structure 10 shown in Fig. 2 is replaced with the resonator 11a shown in Fig. 3. In Fig. 8, the horizontal axis represents frequency [GHz (gigahertz)], the left vertical axis represents gain [dB (decibels)], and the right vertical axis represents reflection phase [deg (degrees)]. Waveform 201 represents the gain of the reflected wave from the unit structure according to the comparative example. Waveform 202 represents the gain of the transmitted wave from the unit structure according to the comparative example. Waveform 203 represents the reflection phase of the unit structure according to the comparative example.

[0034] 9, the horizontal axis represents frequency [GHz], the left vertical axis represents gain [dB], and the right vertical axis represents reflection phase [deg]. Waveform 211 represents the gain of the reflected wave from the unit structure 10. Waveform 212 represents the gain of the transmitted wave from the unit structure 10. Waveform 213 represents the reflection phase of the unit structure 10.

[0035] Comparing waveform 203 and waveform 213, waveform 213 decreases more gradually than waveform 203 after the peak value of the reflection phase has passed. This means that, as shown by waveforms 201 and 211, the embodiment has a better reflected wave gain over a wider band than the comparative example. That is, in the first embodiment, by forming the side surfaces of the resonator in a curved shape, good reflection characteristics can be achieved over a wider band. Note that while FIGS. 8 and 9 have described an example in which good reflection characteristics are achieved over a wider band, in the embodiment, good transmission characteristics can also be achieved over a wider band by forming the side surfaces of the resonator in a curved shape.

[0036] (Reception strength of radio wave control plate) The reception characteristics of the radio wave control plate according to the first embodiment will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a diagram for explaining the reception characteristics of a radio wave control plate according to a comparative example. Fig. 11 is a diagram for explaining the reception characteristics of the radio wave control plate according to the first embodiment.

[0037] The radio wave control board according to the comparative example has a structure in which unit structures each having a resonator 11a as shown in Fig. 3 are arranged two-dimensionally. In Fig. 10, the horizontal axis represents frequency [GHz] and the vertical axis represents reception strength [dB]. Waveform 301 shows the reception characteristics of the radio wave control board according to the comparative example. The reception characteristics of the radio wave control board according to the comparative example show a peak value of reception strength at the design frequency f. The reception characteristics of the radio wave control board according to the comparative example decrease significantly around the design frequency f.

[0038] The radio wave control board according to the first embodiment has a structure in which unit structures each having a resonator 11 as shown in Fig. 4 are arranged two-dimensionally. In Fig. 11, the horizontal axis represents frequency [GHz] and the vertical axis represents reception strength [dB]. Waveform 302 shows the reception characteristics of the radio wave control board according to the first embodiment. The reception characteristics of the radio wave control board according to the first embodiment show a peak value of reception strength at the design frequency f. The reception characteristics of the radio wave control board according to the first embodiment also show high reception strength around the design frequency f.

[0039] As shown by waveforms 301 and 302, the radio wave control board according to the embodiment has a higher reception strength over a wider band than the radio wave control board according to the comparative example.

[0040] As described above, in the first embodiment, by forming at least one side of the side surface of the unit feature in a curved shape, it is possible to achieve high transmission or reflection characteristics over a wide band.

[0041] Second Embodiment A configuration example of a resonator according to a second embodiment will be described with reference to Fig. 12. Fig. 12 is a diagram showing a configuration example of a resonator according to the second embodiment.

[0042] 12 , the resonator 11D has an upper side 111D, a lower side 112D, a left side 113D, and a right side 114D. The lengths of the upper side 111D and the lower side 112D are the same. The lengths of the left side 113D and the right side 114D are the same.

[0043] A curved line 115D is formed between one end of the top side 111D and one end of the left side 113D. A curved line 116D is formed between the other end of the top side 111D and one end of the right side 114D.

[0044] A curved line 117D is formed between one end of the bottom side 112D and the other end of the left side 113D. A curved line 118D is formed between the other end of the bottom side 112D and the other end of the right side 114D.

[0045] In the second embodiment, the curves 115D, 116D, 117D, and 118D are curves that are convex outward from the resonator 11D, that is, the rectangular resonator 11D has four corners with convex outward curves.

[0046] In the second embodiment, it is possible to obtain broadband transmission or reflection characteristics compared to when the side surfaces have irregular curves.

[0047] [Third Embodiment] A third embodiment will be described. It is expected that if the transmission or reflection characteristics of the unit structure 10 are broadened, the slope of the reflection phase relative to the phase within the reflection band of the radio wave control plate will become smaller. In this case, when arranging resonators of different sizes to adjust the desired phase, it may be impossible to adjust the desired phase unless the size of the resonators is dynamically changed. However, since the size of the unit structure 10 is less than half the wavelength of the received radio wave, there is a possibility that the desired phase cannot be achieved due to the constraints on the size of the resonators. Therefore, in the third embodiment, a unit structure is constructed by stacking multiple resonators to broaden the transmission or reflection characteristics and adjust the magnitude of the change in phase adjustment.

[0048] [Unit Structure] A configuration example of a unit structure according to the third embodiment will be described with reference to Fig. 13. Fig. 13 is a diagram showing a configuration example of a unit structure according to the third embodiment.

[0049] As shown in FIG. 13, the unit structure 10A includes a first resonator 41, a second resonator 42, a first reference conductor 51, a second reference conductor 52, a first dielectric layer 61, and a second dielectric layer 62.

[0050] The first resonator 41 is a resonator made of a conductive material. The first resonator 41 is formed in a shape in which one side of the resonator 41 is curved, for example, like the resonator 11 shown in Fig. 4. The first resonator 41 is formed on the upper surface of the unit structure 10A.

[0051] The second resonator 42 is a resonator made of a conductive material. The second resonator 42 is formed in a shape in which one side of the resonator 42 is curved, for example, like the resonator 11 shown in Fig. 4. The second resonator 42 is formed inside the unit structure 10A.

[0052] The first reference conductor 51 is a ground conductor made of a conductive material. The first reference conductor 51 is formed inside the unit structure 10A. The first reference conductor 51 is formed between the first resonator 41 and the second resonator 42. The first resonator 41 and the second resonator 42 are magnetically or capacitively connected via the first reference conductor 51. The first reference conductor 51 is a coupling adjustment conductor that adjusts the strength of coupling between the first resonator 41 and the second resonator 42.

[0053] The second reference conductor 52 is a ground conductor made of a conductive material. The second reference conductor 52 is formed on the lower surface of the unit structure 10A. For example, the second reference conductor 52 is formed over the entire lower surface of the unit structure 10A.

[0054] The first dielectric layer 61 is a dielectric substrate located between the first resonator 41 and the first reference conductor 51. The first resonator 41 is formed on the first dielectric layer 61.

[0055] The second dielectric layer 62 is a dielectric substrate located between the first reference conductor 51 and the second reference conductor 52. The second resonator 42 is formed inside the second dielectric layer 62. The second reference conductor 52 is formed on the second dielectric layer 62.

[0056] That is, the unit structure 10A includes two resonant structures: a first resonant structure 71 including a first resonator 41, a first reference conductor 51, and a first dielectric layer 61, and a second resonant structure 72 including a second resonator 42, a second reference conductor 52, and a second dielectric layer 62. In other words, the unit structure 10A has a multi-stage structure in which a plurality of resonant structures are stacked along the Z-axis direction.

[0057] (Amount of Phase Change) The frequency characteristics of the unit structure according to the third embodiment will be described with reference to Fig. 14 and Fig. 15. Fig. 14 is a diagram for explaining the amount of phase change of the unit structure according to a comparative example. Fig. 15 is a diagram for explaining the amount of phase change of the unit structure according to the third embodiment.

[0058] Fig. 14 shows the amount of phase change of the unit structure 10 shown in Fig. 2. In Fig. 14, the horizontal axis represents frequency [GHz], the left vertical axis represents gain [dB], and the right vertical axis represents reflection phase [deg]. The reflection band F1 indicates the frequency band of radio waves that can be reflected by the unit structure 10. In the unit structure 10, the amount of phase change within the reflection band F1 varies from approximately -135° (245°) to approximately 135°, as shown by waveform 213, and is therefore approximately 90°.

[0059] Figure 15 shows the phase change amount of the unit structure 10A shown in Figure 13. In Figure 15, the horizontal axis represents frequency [GHz], the left vertical axis represents gain [dB], and the right vertical axis represents reflection phase [deg]. Waveform 221 represents the gain of the reflected wave from the unit structure 10A. Waveform 222 represents the gain of the transmitted wave from the unit structure 10A. Waveform 223 represents the reflection phase of the unit structure 10A. Reflection band F2 represents the frequency band of radio waves that can be reflected by the unit structure 10A. In the unit structure 10A, the phase change amount within reflection band F2 varies from approximately 180° to approximately 0°, as shown by waveform 223, and is therefore approximately 180°.

[0060] That is, since the unit structure 10A has multiple stages of stacked resonant structures, the amount of phase change is larger than that of the unit structure 10, which has a single stage of resonant structure. That is, in the third embodiment, the frequency band of reflectable radio waves can be broadened and the amount of phase change can be increased.

[0061] 13 , the unit structure 10A has been described as having two stacked resonant structures, including the first resonator 41, the second resonator 42, the first reference conductor 51, and the second reference conductor 52. However, the present disclosure is not limited to this. In the third embodiment, the unit structure may have three or more stacked resonant structures.

[0062] In the third embodiment, the amount of phase change within the band can be increased by stacking multiple resonators with curved sides, such as the first resonator 41 and the second resonator 42, to form a multi-stage resonator.

[0063] (Effect) The composite resonator according to the first aspect of the present disclosure has a resonance structure including a dielectric layer 31, a resonator 11 extending over a first surface provided on the dielectric layer 31, and a reference conductor 21 facing the resonator 11 via the dielectric layer 31, wherein the resonator 11 has a curve on at least a portion of a side surface. As a result, the present disclosure allows the resonator 11 to have a curve, thereby widening the frequency band of the corresponding radio waves and thereby exhibiting desired characteristics for a wideband radio wave.

[0064] A composite resonator according to a second aspect of the present disclosure is the composite resonator according to the first aspect, wherein the resonator 11 is formed in a polygonal shape and has a curve on at least one side of the side surface of the resonator 11. This allows the present disclosure to appropriately widen the frequency band of the corresponding radio waves and appropriately exhibit desired characteristics for the wideband radio waves.

[0065] A composite resonator according to a third aspect of the present disclosure is the composite resonator according to the first or second aspect, wherein the resonator 11 has a plurality of curves on its side surface, each of which is convex outward from the resonator. This allows the present disclosure to appropriately widen the frequency band of the corresponding radio wave and appropriately exhibit desired characteristics for the wideband radio wave.

[0066] A composite resonator according to a fourth aspect of the present disclosure is the composite resonator according to any one of the first to third aspects, wherein the resonator 11 is formed in a rectangular shape, and the plurality of curves are located at four corners of the resonator 11. This allows the present disclosure to appropriately widen the frequency band of the corresponding radio waves and appropriately exhibit desired characteristics for the wideband radio waves.

[0067] A composite resonator according to a fifth aspect of the present disclosure is the composite resonator according to any one of the first to fourth aspects, including a plurality of resonant structures (71, 72), the plurality of resonant structures (71, 72) being stacked. As a result, the present disclosure provides the resonator 11 with a curve, thereby widening the frequency band of the corresponding radio waves and thereby exhibiting desired characteristics for a wideband radio wave.

[0068] A radio wave control plate 1 according to a sixth aspect of the present disclosure includes a plurality of composite resonators according to any one of the first to fifth aspects, and the plurality of composite resonators are arranged on a first surface. As a result, the present disclosure can exhibit desired characteristics for a wide band of radio waves by providing a curve to resonators 11 and thereby widening the frequency band of the corresponding radio waves.

[0069] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the contents of these embodiments. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the above-described embodiments.

[0070] REFERENCE SIGNS LIST 1 Radio wave control plate 10 Unit structure 11, 11a, 11A, 11B, 11C, 11D Resonator 21 Reference conductor 31 Dielectric layer 41 First resonator 42 Second resonator 51 First reference conductor 52 Second reference conductor 61 First dielectric layer 62 Second dielectric layer 71 First resonant structure 72 Second resonant structure

Claims

1. A composite resonator comprising a resonant structure including: a dielectric layer; a resonator extending over a first surface provided on the dielectric layer; and a reference conductor facing the resonator via the dielectric layer, wherein the resonator has a curve on at least a portion of a side surface.

2. The composite resonator according to claim 1, wherein the resonator is formed in a polygonal shape, and at least one side of the resonator has a curve.

3. The composite resonator according to claim 1 or 2, wherein the resonator has a plurality of curved lines on a side surface, and each of the plurality of curved lines is a curve that is convex to an outside of the resonator.

4. The composite resonator according to claim 3, wherein the resonator is formed in a rectangular shape, and the plurality of curved lines are respectively located at four corners of the resonator.

5. A composite resonator according to claim 1 or 2, comprising a plurality of the resonant structures, the plurality of resonant structures being stacked.

6. A radio wave control plate comprising a plurality of composite resonators according to claim 1, the plurality of composite resonators being arranged side by side on the first surface.