Radio wave control board and composite resonator

Abstract

A radio wave control plate according to the present invention comprises a plurality of unit structures arranged on a surface. The unit structures each comprise a plurality of resonators aligned in a first direction perpendicular to the surface, and dielectric layers positioned between the plurality of resonators. At least one of the plurality of resonators is formed so that at least a section of a peripheral part become thinner towards the end thereof.

Description

Technical Field

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

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The radio wave control plate of the present disclosure includes a plurality of unit structures arranged on a surface, and the unit structure includes a plurality of resonators arranged in a first direction perpendicular to the surface, and a dielectric layer located between the plurality of resonators. At least one of the plurality of resonators has at least a part of its peripheral portion formed thinner toward the end.

[0005] The composite resonator of the present disclosure includes a plurality of resonators arranged in a first direction perpendicular to the surface, and a dielectric layer located between the plurality of resonators. At least one of the plurality of resonators has at least a part of its peripheral portion formed thinner toward the end.

Brief Description of the Drawings

[0006] [Figure 1] FIG. 1 is a diagram for explaining the outline of the radio wave control plate. [Figure 2] FIG. 2 is a diagram showing the outline of the unit structure. [Figure 3] FIG. 3 is a schematic cross-sectional view of the resonator according to the first embodiment. [Figure 4]Figure 4 is a schematic diagram of the resonator according to the first embodiment, viewed from the top surface. [Figure 5] Figure 5 is a diagram illustrating the conductor pattern of the resonator inside the unit structure according to the second embodiment. [Modes for carrying out the invention]

[0007] Embodiments of the present invention will be described in detail below with reference to the attached drawings. However, the present invention is not limited by these embodiments, and in the following embodiments, the same parts are denoted by the same reference numerals to omit redundant explanations.

[0008] In the following explanation, we will establish an XYZ Cartesian coordinate system and describe the positional relationships of each part while referring to this XYZ Cartesian coordinate system. The direction parallel to the X-axis in the horizontal plane will be defined as the X-axis direction, the direction parallel to the Y-axis in the horizontal plane perpendicular to the X-axis will be defined as the Y-axis direction, and the direction parallel to the Z-axis perpendicular to the horizontal plane will be defined as the Z-axis direction. Furthermore, the plane containing the X-axis and Y-axis will be appropriately referred to as the XY plane, the plane containing the X-axis and Z-axis will be appropriately referred to as the XZ plane, and the plane containing the Y-axis and Z-axis will be appropriately referred to as the YZ plane. The XY plane is parallel to the horizontal plane. The XY plane, XZ plane, and YZ plane are orthogonal to each other.

[0009] (Radio wave control panel) Figure 1 will be used to explain the overview of the radio wave control board. Figure 1 is a diagram illustrating the overview of the radio wave control board.

[0010] The radio wave control plate 1 is a plate-shaped member configured to reflect or transmit (refract) radio waves transmitted by a base station. For example, when the radio wave control plate 1 receives radio waves transmitted by a base station, it is configured to reflect or refract those radio waves at a predetermined angle. The radio wave control plate 1 may be made of, for example, a metamaterial that changes the phase of the incident wave.

[0011] As shown in Figure 1, the radio wave control board 1 may include, for example, a substrate 2, and unit structures 10a, 10b, 10c, and 10d. When it is not necessary to distinguish between unit structures 10a and 10d, they are collectively referred to as unit structure 10. Unit structure 10 is also called a composite resonator.

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

[0013] In the radio wave control panel 1, multiple unit structures 10a are arranged along the X-axis on each stage. Multiple unit structures 10b are arranged along the X-axis on the stage above where unit structures 10a are located. Multiple unit structures 10c are arranged along the X-axis on the stage above where unit structures 10b are located. Multiple unit structures 10d are arranged along the X-axis on the stage above where unit structures 10c are installed. In the example shown in Figure 1, unit structures 10a, 10b, 10c, and 10d are arranged periodically along the Y-axis.

[0014] Unit structures 10a, 10b, 10c, and 10d each have different sizes. In the example shown in Figure 1, unit structure 10a is the largest, followed by unit structures 10b, 10c, and 10d in decreasing order of size. In other words, the radio wave control board 1 has a structure in which multiple unit structures 10 of different sizes are arranged periodically.

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

[0016] Figure 2 will be used to explain the overview of the unit structure. Figure 2 is a diagram illustrating the overview of the unit structure.

[0017] As shown in Figure 2, the unit structure 10 includes a first resonator 11a, a second resonator 11b, a third resonator 11c, a fourth resonator 11d, a first reference conductor 21a, a second reference conductor 21b, a third reference conductor 21c, a first dielectric layer 31, a second dielectric layer 32, a third dielectric layer 33, a fourth dielectric layer 34, a fifth dielectric layer 35, and a sixth dielectric layer 36.

[0018] The first resonator 11a is a resonator composed of a conductive material (metal material). The first resonator 11a is formed on the uppermost surface of the unit structure 10.

[0019] The second resonator 11b and the third resonator 11c are resonators made of conductive material. The second resonator 11b and the third resonator 11c are formed inside the unit structure 10.

[0020] The fourth resonator 11d is a resonator composed of a conductive material. The fourth resonator 11d is formed on the bottom surface of the unit structure 10. The bottom surface is also called the back surface. The fourth resonator 11d is also called the second metallic element.

[0021] The first reference conductor 21a is a ground conductor composed of a conductive member. The first reference conductor 21a is formed inside the unit structure 10. The first reference conductor 21a is formed between the first resonator 11a and the second resonator 11b. The first resonator 11a and the second resonator 11b are magnetically or capacitively connected via the first reference conductor 21a. The first reference conductor 21a is a conductor for coupling adjustment that adjusts the strength of the coupling between the first resonator 11a and the second resonator 11b.

[0022] The second reference conductor 21b is a ground conductor composed of a conductive member. The second reference conductor 21b is formed inside the unit structure 10. The second reference conductor 21b is formed between the second resonator 11b and the third resonator 11c. The second resonator 11b and the third resonator 11c are magnetically or capacitively connected via the second reference conductor 21b. The second reference conductor 21b is a conductor for coupling adjustment that adjusts the strength of the coupling between the second resonator 11b and the third resonator 11c.

[0023] The third reference conductor 21c is a ground conductor composed of a conductive member. The third reference conductor 21c is formed inside the unit structure 10. The third reference conductor 21c is formed between the third resonator 11c and the fourth resonator 11d. The third resonator 11c and the fourth resonator 11d are magnetically or capacitively connected via the third reference conductor 21c. The third reference conductor 21c is a conductor for coupling adjustment that adjusts the strength of the coupling between the third resonator 11c and the fourth resonator 11d.

[0024] The first dielectric layer 31 is a dielectric substrate positioned between the first resonator 11a and the first reference conductor 21a. The first dielectric layer 31 has a core layer 311 and a prepreg layer 312.

[0025] The second dielectric layer 32 is a dielectric substrate positioned between the first reference conductor 21a and the second resonator 11b. The second dielectric layer 32 has a core layer 321 and a prepreg layer 322.

[0026] The third dielectric layer 33 is a dielectric substrate located between the second resonator 11b and the second reference conductor 21b. The third dielectric layer 33 has a core layer 331 and a prepreg layer 332.

[0027] The fourth dielectric layer 34 is a dielectric substrate located between the second reference conductor 21b and the third resonator 11c. The fourth dielectric layer 34 has a core layer 341 and a prepreg layer 342.

[0028] The fifth dielectric layer 35 is a dielectric substrate located between the third resonator 11c and the third reference conductor 21c. The fifth dielectric layer 35 has a core layer 351 and a prepreg layer 352.

[0029] The sixth dielectric layer 36 is a dielectric substrate located between the third reference conductor 21c and the fourth resonator 11d. The sixth dielectric layer 36 has a core layer 361 and a prepreg layer 362.

[0030] As shown in Figure 2, the unit structure 10 has seven layers, consisting of a first resonator 11a, a second resonator 11b, a third resonator 11c, a fourth resonator 11d, a first reference conductor 21a, a second reference conductor 21b, and a third reference conductor 21c, but the disclosure is not limited thereto.

[0031] If it is not necessary to distinguish between the first resonator 11a to the fourth resonator 11d, they are collectively referred to as resonator 11. If it is not necessary to distinguish between the first reference conductor 21a to the third reference conductor 21c, they are collectively referred to as reference conductor 21.

[0032] The unit structure 10 is designed such that the dimensions of the conductor patterns of each resonator 11 and each reference conductor 21 are appropriately designed so that the radio wave control plate 1 has the desired reflection or transmission characteristics. However, if the dimensions of the conductor patterns of each resonator 11 and each reference conductor 21 deviate from the design values ​​due to manufacturing variations, the resonant frequency will shift. As a result, the amount of change in the transmission phase or the amount of change in the reflection phase will shift at the desired frequency, which may degrade the communication quality. Since the amount of change in the transmission phase or the reflection phase is large, it is necessary to lower the Q value. Therefore, in this disclosure, the conductor patterns of each resonator 11 are formed to lower the Q value, thereby improving the communication quality of the radio wave control plate 1.

[0033] [First Embodiment] (Conductor pattern of the resonator) The conductor pattern of the resonator according to the first embodiment will be explained using Figures 3 and 4. Figure 3 is a schematic cross-sectional view of the resonator according to the first embodiment. Figure 4 is a schematic view of the resonator according to the first embodiment as seen from the top surface.

[0034] As shown in Figure 3, the resonator 11 is formed with peripheral portions R1 and R2 that are thinner towards the ends. The resonator 11 has, for example, a trapezoidal cross-section. Therefore, the area of ​​the upper surface 11A and the lower surface 11B of the resonator 11 are different. For example, the area of ​​the upper surface 11A of the resonator 11 is smaller than the area of ​​the lower surface 11B. In the first embodiment, the Q value of the unit structure 10 can be reduced by making the peripheral portions R1 and R2 of the resonator 11 thinner towards the ends.

[0035] In this embodiment, at least one of the multiple resonators 11 provided by the radio wave control board 1 only needs to have at least a portion of its peripheral edge thinned towards the end. As shown in Figure 4, when the resonator 11 is rectangular, the resonator 11 has an upper side 11C, a lower side 11D, a left side 11E, and a right side 11F. In this case, the resonator 11 only needs to have at least a portion of at least one of the peripheral edges R3 of the upper side 11C, R4 of the lower side 11D, R1 of the left side 11E, and R2 of the right side 11F thinned towards the end. In this case, since current concentrates and flows in the center of each side of the resonator 11, it is preferable to thin the central portion of at least one of the peripheral edges towards the end. In this embodiment, by thinning the central portion of the peripheral edge towards the end, the Q value of the unit structure 10 can be reduced more appropriately.

[0036] Furthermore, in the example shown in Figure 4, it is more preferable that the entire peripheral portion R1, R2, R3, and R4 (all peripheral portions) are formed to become thinner towards the end. By forming the entire peripheral portion R1, R2, R3, and R4 to become thinner towards the end, the Q value of the unit structure 10 can be reduced more appropriately.

[0037] [Second Embodiment] (Conductor pattern of the resonator inside the unit structure) The conductor pattern of the resonator inside the unit structure according to the second embodiment will be explained using Figure 5. Figure 5 is a diagram illustrating the conductor pattern of the resonator inside the unit structure according to the second embodiment.

[0038] Figure 5 shows a resonator 11 formed inside the unit structure 10. Figure 5 is an example of a Scanning Electron Microscope (SEM) image formed inside the unit structure 10. The resonator 11 is formed inside the unit structure 10 between the core layer 41 and the prepreg layer 42 of the dielectric layer 40. The core layer 41 contains glass cloth 51. The prepreg layer 42 contains glass cloth 52. Glass cloth 51 is larger than glass cloth 52. In this embodiment, of the two dielectric layers sandwiching the resonator 11, the dielectric layer containing a relatively large glass cloth is called the core layer, and the dielectric layer containing a relatively small glass cloth is called the prepreg layer.

[0039] When attempting to thin the edges of the resonator 11 inside the unit structure 10, the resonant frequency may shift and the characteristics may deteriorate depending on whether or not there is glass cloth near the thinned portion. This is because the relative permittivity differs between the resin portion and the glass cloth portion of the dielectric layer. It is difficult to keep the glass cloth away from the resonator 11.

[0040] Therefore, in the second embodiment, as shown in Figure 5, the thickness of the core layer 41 side of the resonator 11 is reduced to keep the relative permittivity around the thinned portion low. Specifically, in the second embodiment, the area of ​​the upper surface 11A on the core layer 41 side is made larger than the area of ​​the lower surface 11B on the prepreg layer 42 side. In other words, in the second embodiment, the distance between the relatively large upper surface 11A and the glass cloth 51 is increased to be greater than the distance between the relatively small lower surface 11B and the glass cloth 52. As a result, the distance between the lower surface 11B and the glass cloth 52 is more likely to be shorter than the distance between the upper surface 11A and the glass cloth 51, so that the resonant frequency does not shift as much, and stable characteristics can be achieved. The upper surface 11A is also called the first surface. The lower surface 11B is also called the second surface.

[0041] [Third Embodiment] (Surface shape of the resonator) The surface shape of the resonator according to the third embodiment will be described.

[0042] When the surface of the resonator 11 of the unit structure 10 is smooth, the conductor loss at the surface is small. Therefore, in the third embodiment, the Q value is reduced by making at least one of the upper and lower surfaces of the resonator 11 rough. In other words, irregularities are formed on at least one of the upper and lower surfaces of the resonator 11. Specifically, the surface roughness of at least one of the upper and lower surfaces of the resonator 11 is preferably 0.2 μm (micrometers) or more, and more preferably 1 μm or more. The surface roughness of the upper or lower surface of the resonator 11 can be calculated, for example, by performing image analysis processing on an SEM image and calculating it as the root mean square roughness. Furthermore, in the third embodiment, it is preferable to form irregularities on both the upper and lower surfaces of the resonator 11. In this case, the surface roughness of the upper and lower surfaces of the resonator 11 may be the same or different. By forming irregularities on both the upper and lower surfaces of the resonator 11, the Q value can be appropriately reduced.

[0043] [Fourth Embodiment] (Surface shape of the resonator) The surface shape of the resonator according to the fourth embodiment will be described.

[0044] As shown in Figure 3, when the areas of the upper surface 11A and the lower surface 11B of the resonator 11 are different, the effect of reducing the Q value differs depending on whether the irregularities are formed on the upper surface 11A or on the lower surface 11B. In the fourth embodiment, it is preferable to form irregularities on at least the surface with the larger area of ​​the upper surface 11A and the lower surface 11B of the resonator 11. In the fourth embodiment, the unit structure 10 can appropriately reduce the Q value and achieve more stable characteristics by forming irregularities on the surface with the larger area of ​​the upper surface 11A and the lower surface 11B of the resonator 11. Furthermore, in the fourth embodiment, it is preferable to form irregularities on both the upper surface 11A and the lower surface 11B of the resonator 11.

[0045] [effect] A radio wave control board 1 according to a first aspect of this disclosure includes a plurality of unit structures 10 arranged on a surface, each unit structure 10 comprising a plurality of resonators 11 arranged in a first direction perpendicular to the surface, and a dielectric layer located between the plurality of resonators 11, wherein at least one of the plurality of resonators 11 is formed to be thinner toward the edge at least a portion of its peripheral edge. According to this disclosure, by forming at least one of the plurality of resonators 11 to be thinner toward the edge at least a portion of its peripheral edge, the Q value can be reduced and communication quality can be improved.

[0046] A radio wave control plate 1 according to a second aspect of this disclosure is a radio wave control plate 1 according to a first aspect, wherein at least a portion of the peripheral edge is formed to be thinner than the average thickness of the resonator toward the end. According to this disclosure, communication quality can be improved by appropriately thinning at least a portion of the peripheral edge toward the end.

[0047] A radio wave control board 1 according to a third aspect of this disclosure is a radio wave control board 1 according to the first or second aspect, wherein at least one of the plurality of resonators 11 has a first surface and a second surface having a smaller area than the first surface, the first surface is located on the core layer side of the dielectric layer, and the second surface is located on the prepreg layer side of the dielectric layer. According to this disclosure, communication quality can be improved by appropriately positioning the first surface and the second surface.

[0048] A radio wave control board 1 according to a fourth aspect of this disclosure is a radio wave control board 1 according to either the first or second aspect, wherein at least one of the plurality of resonators 11 has a first surface and a second surface having a smaller area than the first surface, and the distance between the first surface and the glass cloth included in the dielectric layer in contact with the first surface is longer than the distance between the second surface and the glass cloth included in the dielectric layer in contact with the second surface. According to this disclosure, communication quality can be improved by appropriately shaping the distance between the first surface and the glass cloth and the distance between the second surface and the glass cloth.

[0049] The fifth aspect of this disclosure is a radio wave control board 1 according to any of the first to fourth aspects, wherein at least one of the first surface and the second surface has irregularities formed on its surface. According to this disclosure, by forming irregularities on at least one of the first surface and the second surface, communication quality can be improved.

[0050] The radio wave control board 1 according to the sixth aspect of this disclosure is the radio wave control board 1 according to the fifth aspect, wherein at least the second surface of the first surface and the second surface have irregularities formed on its surface. According to this disclosure, by forming irregularities on at least the second surface, communication quality can be improved.

[0051] The radio wave control board 1 according to the seventh aspect of this disclosure is the radio wave control board 1 according to the sixth aspect, wherein irregularities are formed on both the first and second surfaces. According to this disclosure, the communication quality can be improved by forming irregularities on both the first and second surfaces.

[0052] The radio wave control board 1 according to the eighth aspect of this disclosure is a radio wave control board 1 according to any of the fifth to seventh aspects, wherein the surface roughness of the surface on which the irregularities are formed among the first and second surfaces is 0.2 μm or more. According to this disclosure, communication quality can be improved by appropriately setting the surface roughness.

[0053] A composite resonator according to a ninth aspect of this disclosure comprises a plurality of resonators 11 arranged in a first direction perpendicular to a plane, and a dielectric layer located between the plurality of resonators 11, wherein at least one of the plurality of resonators 11 has at least a portion of its peripheral edge formed to be thinner toward the end. According to this disclosure, by forming at least a portion of the peripheral edge of at least one of the plurality of resonators 11 to be thinner toward the end, the Q factor can be reduced and communication quality can be improved.

[0054] While embodiments of the present disclosure have been described above, the present disclosure is not limited by the content of these embodiments. Furthermore, the aforementioned components include those that are readily conceivable to those skilled in the art, those that are substantially identical, and those that fall within the so-called equivalent range. Moreover, the aforementioned components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the embodiments described above. [Explanation of symbols]

[0055] 1. Radio wave control panel 10 Unit Structure 11 Resonator 11a 1st resonator 11b 2nd resonator 11c 3rd resonator 11d 4th resonator 21a First reference conductor 21b Second reference conductor 21c Third reference conductor 31 First Dielectric Layer 32 Second Dielectric Layer 33 Third Dielectric Layer 34. Fourth dielectric layer 35. Fifth Dielectric Layer 36. Sixth Dielectric Layer 311,321,331,341,351,361,41 Core Layer 312,322,332,342,352,362,42 prepreg layers

Claims

1. It includes multiple unit structures arranged on a surface, The aforementioned unit structure is A plurality of resonators arranged in a first direction perpendicular to the aforementioned surface, A dielectric layer located between the multiple resonators, Equipped with, At least one of the plurality of resonators is formed such that at least a portion of its peripheral edge is thinned toward the end. Radio wave control panel.

2. At least a portion of the peripheral edge is formed to be thinner than the average thickness of the resonator toward the end. The radio wave control board according to claim 1.

3. At least one of the plurality of resonators has a first surface and a second surface having a smaller area than the first surface. The first surface is located on the core layer side of the dielectric layer, The second surface is located on the prepreg layer side of the dielectric layer, The radio wave control board according to claim 1 or claim 2.

4. At least one of the plurality of resonators has a first surface and a second surface having a smaller area than the first surface. The distance between the first surface and the glass cloth included in the dielectric layer in contact with the first surface is longer than the distance between the second surface and the glass cloth included in the dielectric layer in contact with the second surface. The radio wave control board according to claim 1 or claim 2.

5. At least one of the first surface and the second surface has irregularities formed on its surface. The radio wave control board according to claim 3.

6. Of the first and second surfaces, at least the second surface has irregularities formed on its surface. The radio wave control board according to claim 5.

7. Both the first surface and the second surface have irregularities formed on their surfaces. The radio wave control board according to claim 6.

8. Of the first and second surfaces, the surface roughness of the surface on which irregularities are formed is 0.2 μm or more. The radio wave control board according to claim 5.

9. Multiple resonators arranged in a first direction perpendicular to the plane, A dielectric layer located between the multiple resonators, Equipped with, At least one of the plurality of resonators is formed such that at least a portion of its peripheral edge is thinned toward the end. Composite resonator.

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