Frequency selective surface

Abstract

In the first region (R1) of the substrate (2), the first cells (7, 7) adjacent to each other are in a mutually conductive state. The overall size of the first conductor pattern (6) is smaller than the wavelength of the electromagnetic wave incident on the frequency selective surface (1) and the reflectable wavelength. In the second region (R2) of the substrate (2), the second conductive lines (11, 11) constituting the second cells (10, 10) adjacent to each other are in a mutually non-conductive state. The second conductor pattern (9) is configured such that the size of one second unit (10) is smaller than the overall size of the first conductor pattern (6) and the size of the wavelength through which electromagnetic waves can be transmitted.

Description

Technical Field

[0001] The present disclosure relates to a frequency selective surface. Background Art

[0002] Conventionally, frequency selective surfaces for controlling a radio environment and an electromagnetic environment are known, for example, as shown in Patent Documents 1 and 2.

[0003] Patent document 1 discloses a frequency selective surface, which includes a dielectric substrate and a plurality of first conductive patterns formed on a surface of the dielectric substrate. The plurality of first conductive patterns are each configured as a unit cell. The unit cells are arranged on the surface of the dielectric substrate with a spacing therebetween. The unit cell has at least one conductor portion.

[0004] Patent document 2 discloses a frequency selective surface (electromagnetic shielding component) comprising a transparent substrate having insulating properties and a conductive layer component arranged on the substrate. The conductive layer component has a first conductive layer that can selectively reflect electromagnetic waves. The first conductive layer is composed of a metal mesh, which is composed of metal fine wires with a predetermined line width and has a plurality of square openings. In addition, the conductive layer component has a non-conductive portion that can selectively transmit electromagnetic waves (see Patent document 2). Figure 7 ). The non-conductive portion is located inside the first conductive layer and is formed by cutting off a cross-shaped portion from the metal mesh.

[0005] Patent Document 1: WO2021 / 009893

[0006] Patent Document 2: WO2021 / 131962 Summary of the invention

[0007] -Technical problem to be solved by the invention-

[0008] In the frequency selective surface of Patent Document 1, on one surface of the dielectric substrate, there are regions where a plurality of first conductive patterns are arranged and regions where a plurality of first conductive patterns are not arranged. Similarly, in the frequency selective surface of Patent Document 2, on the substrate, there are regions where a first conductive layer is arranged and regions where a first conductive layer is not arranged (i.e., regions where a non-conductive portion is arranged). That is, in the frequency selective surfaces of the above-mentioned documents, the distribution state of the conductive patterns on the substrate is uneven.

[0009] Therefore, for example, when the frequency selective surface disclosed in the above-mentioned documents is installed on a window (a flat or curved window surface) of a building, when the window is observed from the inside or outside of the building, it is easy to distinguish between the area where the conductive pattern is arranged and the area where the conductive pattern is not arranged. That is, when the window is observed from the inside or outside of the building, for example, only the wire portion (equivalent to the metal fine wire in Patent Document 2) constituting the conductor pattern is relatively conspicuous. As described above, there is a problem that the aesthetics of the frequency selective surface is poor in certain usage conditions, and the visibility of the frequency selective surface is reduced.

[0010] In addition, Patent Document 2 also shows that the above-mentioned non-conductive portion adopts a configuration in which the metal mesh is oxidized into a cross shape, instead of a configuration in which the non-conductive portion is formed by cutting off a cross-shaped portion from the metal mesh. However, in this configuration, it is difficult to see the oxidized metal mesh, resulting in only the first conductive layer being relatively conspicuous. As a result, like the configuration in which the non-conductive portion is formed by cutting off a cross-shaped portion from the metal mesh, even the configuration in which the metal mesh is oxidized into a cross shape has the following problem: the visibility of the frequency selective surface decreases under certain usage conditions.

[0011] The present disclosure is completed to solve the above technical problems, and its purpose is to obtain a frequency selective surface that not only ensures the function of properly controlling electromagnetic waves but also optimizes visibility.

[0012] -Technical solutions to solve technical problems-

[0013] In order to achieve the above-mentioned purpose, an embodiment of the present disclosure relates to a frequency selective surface, the frequency selective surface includes a substrate, a first conductor pattern and a second conductor pattern, the substrate is provided with a first area and a second area, the first conductor pattern is at least one, which is arranged in the first area of ​​the substrate and has a plurality of first units consisting of a plurality of first conductive lines, the second conductor pattern is at least one, which is arranged in the second area of ​​the substrate and has a plurality of second units consisting of a plurality of second conductive lines. The plurality of first units are configured so that the first units adjacent to each other are in a state of mutual conduction. The first conductor pattern is configured so that the overall size of the first conductor pattern is smaller than the wavelength of the electromagnetic wave incident on the frequency selective surface and can reflect the wavelength of the electromagnetic wave. The plurality of second units are configured so that the second conductive lines constituting the second units adjacent to each other are in a state of mutual non-conduction. Furthermore, the second conductor pattern is configured so that the size of one second unit is smaller than the overall size of the first conductor pattern and can transmit the wavelength of the electromagnetic wave.

[0014] - Effects of the Invention -

[0015] According to the present disclosure, it is possible to obtain a frequency selective surface which ensures both a function for appropriately controlling electromagnetic waves and optimized visibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a plan view showing the entire frequency selective surface according to an embodiment of the present disclosure;

[0017] Figure 2 It is enlarged to show Figure 1 A partial enlarged top view of part II;

[0018] Figure 3 It is enlarged to show Figure 2 A partial enlarged top view of part III;

[0019] Figure 4 is along Figure 2 A cross-sectional view taken along line IV-IV;

[0020] Figure 5 This is a graph briefly showing the measurement results of a reference example based on the viewpoint of how the relationship between the frequency of the electromagnetic wave and the transmission loss behaves depending on the presence or absence of the second region;

[0021] Figure 6 is equivalent to Figure 2 , which shows the first and second conductor patterns of Modification 1 of the embodiment;

[0022] Figure 7 is equivalent to Figure 2 , which shows the first and second conductor patterns of Modification 2 of the embodiment;

[0023] Figure 8 is equivalent to Figure 2 , which shows the first and second conductor patterns of Modification 3 of the embodiment;

[0024] Fig. 9 is equivalent to Figure 2 , which shows the first and second conductor patterns of Modification 4 of the embodiment;

[0025] Fig.10 is equivalent to Figure 2 , which shows the first and second conductor patterns of Modification 5 of the embodiment;

[0026] Fig.11 is equivalent to Figure 2 , which shows the first and second conductor patterns and the third conductor pattern of the modification example 6 of the embodiment;

[0027] Fig.12 is equivalent to Figure 2, which shows the first and second conductor patterns and the third conductor pattern of variation example 7 of the implementation method. DETAILED DESCRIPTION

[0028] The following detailed description of the embodiments of the present disclosure is based on the accompanying drawings. The following description of the embodiments is merely an example of the present disclosure in essence, and is not intended to limit the present disclosure, its application objects, or its use.

[0029] Figure 1 The overall structure of a frequency selective surface 1 (FSS) according to an embodiment of the present disclosure is shown. The frequency selective surface 1 is used to control the radio environment and the electromagnetic environment. Specifically, the frequency selective surface 1 can be installed on a window of a building, for example, to control electromagnetic waves incident from the outside of the building to the inside.

[0030] Here, the above-mentioned "control" refers to selectively reflecting and / or transmitting electromagnetic waves having a predetermined frequency propagating in space. In the following description, the electromagnetic waves incident on the frequency selective surface 1 are simply referred to as "electromagnetic waves".

[0031] It should be noted that, in this embodiment, for the sake of convenience, Figure 1 The direction from the left side of the paper to the right side is defined as the first direction X, which will be from Figure 1 The direction from the lower side of the paper toward the upper side is defined as the second direction Y.

[0032] (Substrate)

[0033] like Figure 1 As shown, the frequency selective surface 1 includes a substrate 2. The substrate 2 is formed to be approximately square in plan view. The substrate 2 is formed in a film shape.

[0034] On the substrate 2 , a plurality of (nine in the example of the drawing) first regions R1 and one second region R2 are provided.

[0035] Each of the plurality of first regions R1 is configured to be a region that can selectively reflect the electromagnetic wave. Specifically, in each first region R1, Figure 1 Near side of paper (or Figure 1 The electromagnetic wave incident on the frequency selective surface 1 is directed toward Figure 1 Near side of paper (or Figure 1 The first regions R1 are arranged on the substrate 2 with a spacing therebetween. The first regions R1 are arranged along the first direction X and the second direction Y, respectively. Each first region R1 is approximately square. It should be noted that Figure 1In order to clearly show each first region R1 , each first region R1 is filled with a darker dot shadow.

[0036] The second region R2 is set as a region that can selectively transmit the electromagnetic wave. Figure 1 Near side of paper (or Figure 1 The electromagnetic wave incident on the frequency selective surface 1 is directed toward Figure 1 Far side of the paper (or Figure 1 The second region R2 is located outside the plurality of first regions R1 on the substrate 2. Figure 1 In order to distinguish each first region R1 from the second region R2 , the second region R2 is filled with a dot shadow lighter than the dot shadow filled with each first region R1 .

[0037] like Figure 4 As shown, the substrate 2 has a film base material 3. The film base material 3 is formed of a transparent resin material such as PET (polyethylene terephthalate), polycarbonate, COP (cycloolefin polymer), COC (cycloolefin copolymer), etc.

[0038] like Figure 4 As shown, the substrate 2 has a groove forming layer 4. The groove forming layer 4 is a layer for forming a groove portion 5 described later. The groove forming layer 4 is formed of a resin material having insulation and light transmittance. The groove forming layer 4 is laminated on one surface of the film substrate 3. The thickness of the groove forming layer 4 is, for example, 1.0 μm to 7.0 μm.

[0039] like Figure 4 As shown in FIG. 1 , a plurality of grooves 5 are provided on the substrate 2. The plurality of grooves 5 extend linearly so as to form a predetermined pattern described later on one surface of the substrate 2.

[0040] The groove 5 is formed in a bottomed shape that is recessed in the thickness direction of the substrate 2 (direction from the groove-forming layer 4 toward the film base 3). The groove depth of the groove 5 is set to, for example, 0.3 μm to 5.0 μm. The groove width of the groove 5 is 10 μm or less.

[0041] It should be noted that a rounded corner is formed at the corner between the side and bottom of the groove portion 5. It should be noted that a rounded corner may not be formed at the corner. In addition, the side of the groove portion 5 may also be inclined in a manner that gradually expands from the bottom of the groove portion 5 toward the opening.

[0042] (First Conductor Pattern)

[0043] like Figure 1 and Figure 2As shown, the frequency selective surface 1 includes a plurality of first conductor patterns 6. Each first conductor pattern 6 is arranged in each first region R1 of the substrate 2. The plurality of first conductor patterns 6 are arranged on the substrate 2 with a spacing therebetween. Each first conductor pattern 6 is approximately square in plan view. Each first conductor pattern 6 is a mesh structure in which a plurality of first units 7 described later are regularly arranged (see Figure 2 ). It should be noted that Figure 1 In the figure, for the convenience of illustration, the detailed structure of the first conductor pattern 6 is omitted.

[0044] like Figure 2 As shown, each first conductor pattern 6 has a plurality of first units 7. The plurality of first units 7 are formed of a plurality of first conductive lines 8.

[0045] Each first conductive line 8 extends in the first direction X or the second direction Y. The plurality of first conductive lines 8 are arranged at a predetermined pitch (equal pitch in the example shown in the figure) in the first direction X or the second direction Y. The line width of each first conductive line 8 is set to, for example, 10 μm or less.

[0046] Each first cell 7 is formed in a closed shape. Each first cell 7 of this embodiment is in a substantially square shape. The plurality of first cells 7 are configured so that the first cells 7 adjacent to each other are in a state of conduction with each other.

[0047] Furthermore, the first conductor pattern 6 is configured such that the entire size of the first conductor pattern 6 is smaller than the wavelength of the electromagnetic wave incident on the frequency selective surface 1 and is large enough to reflect the wavelength of the electromagnetic wave.

[0048] Here, the length of one side of the square constituting each first conductor pattern 6 is set to Figure 2 The dimension P1 shown is equivalent to the length of the first conductive line 8. The dimension P1 is set to, for example, 1 / 10 of the wavelength of the electromagnetic wave.

[0049] As a specific example of the dimension P1, when the frequency of the electromagnetic wave is, for example, 28 GHz (i.e., the wavelength of the electromagnetic wave is about 1 cm), the dimension P1 is set to 1 mm, which is equivalent to 1 / 10 of the wavelength of the electromagnetic wave. If the dimension P1 is set (i.e., the overall size of each first conductor pattern 6 having a square with a side length of the dimension P1), the conductor resistance of each first conductive line 8 is relatively small. In this way, the reflection effect of each first conductive line 8 on the electromagnetic wave is improved. That is, the reflection effect of the first conductor pattern 6 on the electromagnetic wave can be improved.

[0050] (Second Conductor Pattern)

[0051] like Figure 1 and Figure 2As shown, the frequency selective surface 1 includes a second conductor pattern 9. The second conductor pattern 9 is arranged in the second region R2 of the substrate 2. The second conductor pattern 9 is formed to surround each first conductor pattern 6 (refer to Figure 1 The second conductor pattern 9 is a mesh structure in which a plurality of second units 10 described later are regularly arranged (see Figure 2 ). It should be noted that Figure 1 In the figure, for the convenience of illustration, the detailed structure of the second conductor pattern 9 is omitted.

[0052] like Figure 2 As shown, the second conductor pattern 9 has a plurality of second units 10. In this embodiment, each second unit 10 is formed in a non-closed state by a slit 12 described later. Each second unit 10 is, for example, substantially square.

[0053] Each second unit 10 is composed of a plurality of second conductive lines 11. Each second unit 10 is mainly composed of four second conductive lines 11 that are independent of each other. Each second conductive line 11 extends along the first direction X or the second direction Y. The plurality of second conductive lines 11 are arranged in the first direction X or the second direction Y with a predetermined spacing (equal spacing in the example shown in the figure).

[0054] It should be noted that each second unit 10 is formed by a portion of a first conductive line 8 and three second conductive lines 11 near the periphery of the first conductor pattern 6. Each second unit 10 located near the periphery of the first conductor pattern 6 and each first unit 7 located on the periphery of the first conductor pattern 6 are not connected to each other due to the slits 12 described later.

[0055] like Figure 2 and Figure 3 As shown, a slit 12 is formed between the second conductive lines 11, 11 adjacent to each other. The slit 12 is formed between the second conductive lines 11, 11 adjacent to each other in the first direction X and the second direction Y, respectively. In this embodiment, the slit 12 is arranged at a position corresponding to the corner portion of the approximately square shape constituting each second unit 10. In this way, in the second units 10, 10 adjacent to each other, the ends of the second conductive lines 11, 11 are arranged with a predetermined spacing between each other. The length of the slit 12 ( Figure 3 The dimension S shown in FIG. 1 is set to be larger than the line width ( Figure 3 The dimension W shown in the figure) should be noted that Figure 3 In FIG. 1 , the slit 12 is virtually shown by a two-dot chain line.

[0056] In this embodiment, the slits 12 are provided so that the plurality of second conductive lines 11 are independent of each other. In this way, the adjacent second units 10, 10 are not connected to each other. That is, the second conductor pattern 9 is configured as a so-called dummy pattern. Moreover, the second conductor pattern 9 has a better transmission effect on the electromagnetic wave than the first conductor pattern 6 by providing the slits 12.

[0057] In addition, slits 12 are also formed between each first conductive line 8 located at the periphery of the first conductive pattern 6 and each second conductive line 11 of each second unit 10 located near the periphery of the first conductive pattern 6. In this way, each first conductive line 8 and each second conductive line 11 are not connected to each other. In other words, the first conductive pattern 6 and the second conductive pattern 9 are not connected to each other.

[0058] Furthermore, the second conductor pattern 9 is configured such that the size of one second unit 10 is smaller than the entire size of the first conductor pattern 6 and is a size that can transmit the wavelength of the electromagnetic wave.

[0059] The length of one side of the approximately square constituting each second unit 10 is set to Figure 2 The dimension P2 shown in FIG. 1 is equivalent to the spacing between the second conductive lines 11, 11 opposite to each other in the first direction X or the second direction Y. The length of each second conductive line 11 ( Figure 3 The dimension L shown in the figure is formed to be shorter than the length (dimension P2) of one side of the approximate square constituting each second unit 10. Specifically, each second conductive line 11 is configured such that its length (dimension L) is less than 1 / 50 of the wavelength of the electromagnetic wave. More preferably, the length (dimension L) of each second conductive line 11 is set to be less than 1 / 100 of the wavelength of the electromagnetic wave.

[0060] As a specific example of the length of each second conductive line 11, when the frequency of the electromagnetic wave is 28 GHz (i.e., the wavelength of the electromagnetic wave is about 1 cm), the length (dimension L) of each second conductive line 11 is set to 100 μm, which is equivalent to 1 / 100 of the wavelength of the electromagnetic wave. If the length of each second conductive line 11 (i.e., the size of the second unit 10 composed of a plurality of second conductive lines 11) is set, the conductor resistance of each second conductive line 11 is relatively large. In this way, the transmission effect of each second conductive line 11 on the electromagnetic wave will be improved. As a result, the transmission effect of the second conductor pattern 9 on the electromagnetic wave will be improved.

[0061] It should be noted that when the resistance of the conductor is relatively small and the volume of the conductor is relatively large, the number of free electrons in the conductor is relatively large, and the effect on the electromagnetic wave is relatively large. That is, the reflection effect on the electromagnetic wave will be improved. On the other hand, when the resistance of the conductor is relatively large and the volume of the conductor is relatively small, the number of free electrons in the conductor is relatively small, and the effect on the electromagnetic wave is relatively small. That is, the transmission effect on the electromagnetic wave will be improved.

[0062] like Figure 3 As shown, in the first direction X, the distance between the end of the second conductive line 11 extending along the first direction X and the second conductive line 11 extending along the second direction Y (ie, Figure 3 The dimension A) shown is preferably set to be greater than 1 μm. Similarly, in the second direction Y, the spacing between the end of the second conductive line 11 extending in the second direction Y and the second conductive line 11 extending in the first direction X is also preferably set to be greater than 1 μm. In this way, if the shortest distance between the mutually orthogonal second conductive lines 11, 11 is set to be greater than 1 μm, the higher the frequency of the electromagnetic wave, the more the transmittance of the electromagnetic wave in the second conductor pattern 9 can be improved.

[0063] In order to ensure transparency, the first conductor pattern 6 and the second conductor pattern 9 are both configured to have a total light transmittance of more than 70%. In addition, each second conductive line 11 is configured to have a line width ( Figure 3 The dimension W) shown is less than 10 μm. The line width of the second conductive line 11 may have the same line width as the line width of the first conductive line 8. It should be noted that the above-mentioned "full light" may also be visible light.

[0064] (Cross-sectional structure of the first and second conductive lines)

[0065] like Figure 4 As shown, the first conductive line 8 includes a bonding layer 21, a conductive layer 22 and a blackening layer 25. In addition, like the first conductive line 8, the second conductive line 11 also includes a bonding layer 21, a conductive layer 22 and a blackening layer 25, which are not shown. In this embodiment, the main component of the conductive material constituting the conductive layer 22 of the first conductive line 8 is the same as the main component of the conductive material constituting the conductive layer 22 of the second conductive line 11.

[0066] The bonding layer 21 is an element for ensuring the bonding of the conductive layer 22 to the groove portion 5. The bonding layer 21 is, for example, a metal layer formed of a metal nitride or a metal oxide, and the metal nitride or the metal oxide contains at least one metal selected from the group consisting of Ti, Al, V, W, Ta, Si, Cr, Ag, Mo, Cu and Zn. The bonding layer 21 may also be a layered body formed by stacking a plurality of layers of different compositions. The bonding layer 21 is stacked in the groove portion 5 in a thin film form, for example, by evaporation or sputtering.

[0067] The conductive layer 22 is an element for ensuring the conductivity of each of the first conductive wire 8 and the second conductive wire 11. The conductive layer 22 is buried in the groove portion 5. The conductive layer 22 is composed of a seed layer 23 and a main layer 24. The seed layer 23 and the main layer 24 are both formed of a conductive material. The conductive material is suitable for a conductive metal such as copper (Cu) or silver (Ag). It should be noted that, for example, a transparent conductive material with light transmittance, such as a conductive resin material, indium tin oxide, tin oxide, etc., can also be used instead of the above-mentioned conductive metal.

[0068] The seed layer 23 has the function of improving the bonding property between the bonding layer 21 and the main layer 24. Specifically, the seed layer 23 acts as a cathode for laminating a plating solution such as copper (Cu) on the bonding layer 21, for example, when an electroplating process is performed to form the main layer 24. The seed layer 23 is laminated on the bonding layer 21 in a thin film form, for example, by evaporation or sputtering. It should be noted that when the main layer 24 is formed by a method different from the electroplating process, the seed layer 23 may not be provided.

[0069] The main layer 24 is formed, for example, by evaporation, sputtering, chemical plating or electroplating. In this embodiment, the main layer 24 is stacked on the seed layer 23 by electroplating. It should be noted that after the electroplating, the seed layer 23 and the main layer 24 are formed into one body, and the interface between the seed layer 23 and the main layer 24 is in an indistinguishable state.

[0070] The black layer 25 is stacked on the portion of the conductive layer 22 located on the opening side of the groove 5. The thickness of the black layer 25 is, for example, 7 nm to 10 nm. The black layer 25 has the function of making the first conductive line 8 and the second conductive line 11 difficult to see when the frequency selective surface 1 is observed from the outside.

[0071] The blackened layer 25 is formed by replacing copper grains located at the boundary (so-called "grain boundary") between copper grains on the surface of the conductive layer 22 (the main layer 24) with palladium (blackening treatment). Specifically, in the blackening treatment, intergranular corrosion is carried out along the boundary (grain boundary) between copper grains located on the surface of the main layer 24, and the copper grains constituting the surface of the main layer 24 are replaced with palladium. In this way, the blackened layer 25 is stacked on the surface of the main layer 24.

[0072] [Functions and Effects of Implementation Methods]

[0073] As described above, the plurality of first units 7 are configured such that adjacent first units 7 and 7 are in a mutually conductive state. The first conductor pattern 6 is configured such that the overall size of the first conductor pattern 6 is smaller than the wavelength of the electromagnetic wave incident on the frequency selective surface 1 and can reflect the wavelength. In this way, each first region R1 where each first conductor pattern 6 is arranged can be configured as a region that can selectively reflect the electromagnetic wave incident on the frequency selective surface 1.

[0074] In addition, the plurality of second units 10 are configured such that the second conductive lines 11, 11 constituting the mutually adjacent second units 10, 10 are not connected to each other. The second conductor pattern 9 is configured such that the size of one second unit 10 is smaller than the overall size of the first conductor pattern 6 and is a size that can transmit the wavelength of the electromagnetic wave. In this way, the second region R2 where the second conductor pattern 9 is arranged can be configured as a region that can selectively transmit the electromagnetic wave incident on the frequency selective surface 1.

[0075] Moreover, in the frequency selective surface 1, each first conductor pattern 6 configured to be in a conductive state between the first units 7, 7 and the second conductor pattern 9 (so-called dummy pattern) configured to be in a non-conductive state between the second units 10, 10 coexist on the substrate 2 as the first region R1 and the second region R2. In this way, it is easy to make the distribution state of the conductor patterns on the substrate 2 uniform. As a result, when the frequency selective surface 1 is mounted on a window of a building, for example, it is difficult to distinguish between each first conductor pattern 6 and the second conductor pattern 9 (dummy pattern) when observing the window from the inside or outside of the building. That is, the following phenomenon is unlikely to occur: when observing the window from the inside or outside of the building, for example, only each first conductor pattern 6 (a plurality of first conductive lines 8) is relatively conspicuous. In this way, the aesthetics of the frequency selective surface 1 can be improved under appropriate usage conditions.

[0076] Therefore, in the embodiment of the present disclosure, it is possible to obtain a frequency selective surface 1 which not only ensures the function for appropriately controlling the above-mentioned electromagnetic waves but also optimizes visibility.

[0077] Here, Figure 5The results of a reference example measured by the so-called "free space method" (hereinafter referred to as "measurement results of the reference example") are shown based on the viewpoint of how the relationship between the frequency of electromagnetic waves and the transmission loss behaves depending on the presence or absence of the second region R2 (the presence or absence of the second conductor pattern 9). Figure 5 The measurement example indicated by “Sp1” in FIG. 1 (hereinafter referred to as “measurement example Sp1”) is a measurement example related to a configuration in which the first region R1 and the second region R2 are provided on the substrate 2 (that is, a configuration equivalent to the frequency selective surface 1 involved in the embodiment of the present disclosure). Figure 5 The measurement example shown as "Sp2" in FIG. 1 (hereinafter referred to as "measurement example Sp2") is a measurement example related to a configuration in which only the first region R1 is provided on the substrate 2 (not shown, a configuration different from the frequency selective surface 1). Figure 5 In both measurement examples Sp1 and Sp2, the length of the first conductive line 8 and / or the length of the second conductive line 11 is set close to the frequency of the electromagnetic wave (the above-mentioned "28 GHz") at which the transmission effect on the electromagnetic wave is minimum.

[0078] according to Figure 5 In the measurement examples Sp1 and Sp2, when the frequency of the electromagnetic wave is around 28 GHz, the transmission loss (equivalent to Figure 5 No significant difference was observed in the vertical axis of the measurement examples Sp1 and Sp2. That is, in the measurement examples Sp1 and Sp2, when the frequency of the electromagnetic wave is around 28 GHz, the transmission effect is substantially the same. Therefore, in the configuration in which the first region R1 and the second region R2 are provided on the substrate 2, the same aesthetics as the configuration in which only the first region R1 is provided on the substrate 2 can be obtained. Figure 5 The measurement results of the reference example shown can also prove that the visibility of the frequency selective surface 1 is optimized.

[0079] In addition, the first conductor pattern 6 and the second conductor pattern 9 are both configured to have a total light transmittance of more than 70%, and each second conductive line 11 is configured to have a line width of less than 10 μm and a length of less than 1 / 50 of the wavelength of the electromagnetic wave. According to the above configuration, in the second region R2, transparency can be ensured and the electromagnetic wave can be appropriately transmitted.

[0080] In addition, in the first direction X, the distance (dimension A) between the end of the second conductive line 11 extending in the first direction X and the second conductive line 11 extending in the second direction Y is set to be greater than 1 μm. According to the above setting, the higher the frequency of the electromagnetic wave, the higher the transmittance of the electromagnetic wave in the second conductor pattern 9 can be.

[0081] Furthermore, the substrate 2 is formed into a film shape. This makes it easy to attach the frequency selective surface 1 to, for example, a window of a building.

[0082] Furthermore, each of the first conductive line 8 and the second conductive line 11 includes a conductive layer 22 embedded in the groove portion 5. With the conductive layer 22, the conductivity of each of the first conductive line 8 and the second conductive line 11 can be ensured.

[0083] Furthermore, the main component of the conductive material constituting the conductive layer 22 of the first conductive wire 8 is the same as the main component of the conductive material constituting the conductive layer 22 of the second conductive wire 11. In this way, the manufacturing cost of the frequency selective surface 1 can be suppressed.

[0084] The first conductive line 8 and the second conductive line 11 each further include a blackened layer 25 laminated on a portion of the conductive layer 22 located on the opening side of the groove portion 5. The blackened layer 25 makes the first conductive line 8 and the second conductive line 11 difficult to see when the frequency selective surface 1 is observed from the outside.

[0085] [Variation 1 of the embodiment]

[0086] In the above embodiment, the slits 12 are arranged at positions corresponding to the corners of the approximately square shape constituting each second unit 10, but the present invention is not limited to this. Figure 6 As shown in the modification 1, the slits 12 are arranged in the middle of each side of the approximately square forming the second unit 10. That is, in this modification, the second conductive lines 11 extending in the first direction X and the second conductive lines 11 extending in the second direction Y intersect each other (so-called cross shape).

[0087] As in the above embodiment, when the slits 12 are arranged in this way, the plurality of second conductive lines 11 are also independent of each other. That is, the second conductive lines 11, 11 constituting the second units 10, 10 adjacent to each other are not connected to each other. In this way, the second conductor pattern 9 can be configured as a dummy pattern. In addition, the second conductor pattern 9 of this modified example is also provided with the slits 12, so that the transmission effect of the above electromagnetic waves is better than that of the first conductor pattern 6.

[0088] [Variation 2 of the embodiment]

[0089] In addition, you can also Figure 7 As in the variation 2 shown in the figure, the slits 12 are arranged at positions corresponding to the corners of the approximate square constituting the second unit 10 and at the midpoints of each side of the approximate square. As in the above embodiment and the variation 1, in this variation, the second conductor pattern 9 can also be configured as a dummy pattern. In addition, the second conductor pattern 9 of this variation is also provided with the slits 12, so that the transmission effect of the above electromagnetic waves is better than that of the first conductor pattern 6.

[0090] [Variation 3 of the embodiment]

[0091] In the above embodiment, the first unit 7 and the second unit 10 are both approximately square, but the present invention is not limited to this embodiment. Figure 8 As shown in the third modification, both the first unit 7 and the second unit 10 are approximately circular.

[0092] In this modification, mutually adjacent first units 7, 7 are arranged in a manner that the outer edges of the approximately circular shapes are tangent to each other. That is, mutually adjacent first units 7, 7 are in a state of mutual conduction. In this way, as in the above embodiment, each first region R1 where each first conductor pattern 6 is arranged can be set as a region that can selectively reflect the above electromagnetic wave.

[0093] In addition, in the above-mentioned embodiment, the case where each second unit 10 is formed into a non-closed state due to the slit 12 is shown, but it is not limited to this mode. For example, each second unit 10 can also be formed into a closed state as in Modification Example 3. Specifically, in Modification Example 3, the slit 12 is not provided, and the plurality of second units 10, each formed into a closed state, are arranged with a spacing between each other. As in the above-mentioned embodiment, in this mode, the plurality of second conductive lines 11 are also independent of each other. That is, the mutually adjacent second units 10, 10 are not conductive to each other. In this way, the second conductor pattern 9 can be configured as a virtual pattern. Moreover, in the second conductor pattern 9 of this modification example, the second units 10, 10 are arranged with a spacing between each other, so the transmission effect on the above-mentioned electromagnetic waves is better than that of the first conductor pattern 6.

[0094] [Variations 4 and 5 of the embodiment]

[0095] In addition, you can also Fig. 9 As in the modification example 4 shown in FIG. 1 , only the second conductor pattern 9 shown in the above embodiment is replaced with the second conductor pattern 9 shown in the above modification example 3. Fig.10 As in the fifth modification shown in the figure, only the first conductor pattern 6 shown in the above embodiment is replaced with the first conductor pattern 6 shown in the third modification.

[0096] [Variation 6 of the embodiment]

[0097] In addition, in the frequency selective surface 1 involved in the above embodiment, the case where the first conductor pattern 6 and the second conductor pattern 9 are included is shown, but it is not limited to this mode. Fig.11 As in the sixth modified example shown, the frequency selective surface 1 further includes a third conductor pattern 30 .

[0098] The third conductor pattern 30 is configured to have a lower reflectivity to the electromagnetic wave than the first conductor pattern 6. The third conductor pattern 30 is arranged in the second region R2 of the substrate 2. The third conductor pattern 30 and the first conductor pattern 6 are in a conductive state.

[0099] The third conductor pattern 30 has a plurality of third units. The plurality of third units are composed of a plurality of third conductive lines 31. It should be noted that the main structure of the third conductive line 31 is the same as that of the first conductive line 8, so a detailed description thereof is omitted. Fig.11 In order to simplify the diagram, the symbol of the third unit is omitted.

[0100] Each third unit is formed in a closed shape. Each third unit is approximately square. The size of each third unit is equivalent to the size when four first units 7 are combined into an approximately square. That is, the size of each third unit is larger than the first unit 7. In addition, the plurality of third units are configured so that the third units adjacent to each other are in a mutually conductive state.

[0101] In this modification, the second conductor pattern 9 and the third conductor pattern 30 are arranged to overlap each other in the second region R2. Specifically, in this modification, four second cells 10 are configured to be located inside a substantially square shape constituting one third cell.

[0102] In the frequency selective surface 1 of this modification, the first conductor pattern 6 is located in the first region R1, and the second conductor pattern 9 and the third conductor pattern 30 are located in the second region R2 in a mixed state. In this way, the reflectivity of the electromagnetic wave can be made different between the first region R1 and the second region R2. Moreover, by making the second conductor pattern 9 and the third conductor pattern 30 mixed in the second region R2, the distribution state of the conductor pattern on the substrate 2 can be made uniform. That is, the first conductor pattern 6 with a relatively high wiring density of the conductive line is less conspicuous than the third conductor pattern 30 with a relatively low wiring density of the conductive line. As a result, when the frequency selective surface 1 is mounted on a window of a building, for example, it is difficult to distinguish the first conductor pattern 6, the second conductor pattern 9, and the third conductor pattern 30 when observing the window from the inside or outside of the building. Therefore, in this modification, the visibility of the frequency selective surface 1 can also be optimized.

[0103] [Variation 7 of the embodiment]

[0104] In the above embodiment, the first conductor patterns 6 and 6 arranged at a predetermined interval are shown to be non-conductive with each other due to the second conductor pattern 9, but the present invention is not limited to this embodiment. Fig.12As shown in the seventh modification, a connection element 41 is provided between adjacent first conductor patterns 6, 6, and the connection element 41 is used to electrically connect each first conductor pattern 6 to an external control circuit 40. The connection element 41 is formed of, for example, a varactor diode.

[0105] In this modification, the connection element 41 is provided between the first conductor patterns 6 and 6 in the second direction Y. That is, the first conductor patterns 6 and 6 facing each other in the second direction Y are in a state of mutual conduction due to the connection element 41. Fig.12 A connection element 41 is also provided between the first conductor pattern 6 on the lower side of the paper and the external control circuit 40. In this way, the three first conductor patterns 6 arranged along the second direction Y are electrically connected to the external control circuit 40. According to the above configuration, the reflection performance of the first conductor pattern 6 to the above electromagnetic waves can be appropriately adjusted.

[0106] [Other embodiments]

[0107] In the frequency selective surface 1 according to the above embodiment, the substrate 2 includes one film substrate 3, but the present invention is not limited to this embodiment. For example, the substrate 2 may be a laminated body (not shown) formed by laminating a plurality of film substrates 3.

[0108] In the frequency selective surface 1 according to the above embodiment, the groove-forming layer 4 is provided on one surface of the film substrate 3 , but the present invention is not limited to this embodiment. That is, the groove-forming layer 4 may be provided on the other surface of the film substrate 3 .

[0109] In the frequency selective surface 1 involved in the above embodiment, the first conductor pattern 6 and the second conductor pattern 9 are formed on one surface of the substrate 2, but the present invention is not limited to this. That is, the first conductor pattern 6 can be formed on one surface of the substrate 2, and the second conductor pattern 9 can be formed on the other surface of the substrate 2.

[0110] In the frequency selective surface 1 according to the above embodiment, a case where a plurality of first conductor patterns 6 are included is shown, but the present invention is not limited to this embodiment. That is, the frequency selective surface 1 only needs to include at least one first conductor pattern 6 .

[0111] In the frequency selective surface 1 according to the above embodiment, a case is shown in which one second conductor pattern 9 is included, but the present invention is not limited to this embodiment. That is, the frequency selective surface 1 may include a plurality of second conductor patterns 9 .

[0112] In the above embodiment, each first unit 7 is shown to be approximately square, but the present invention is not limited to this. For example, each first unit 7 may be approximately rhombus-shaped. Each second unit 10 may also be approximately rhombus-shaped instead of the approximately square shown in the above embodiment.

[0113] In the above embodiment, the first conductive lines 8, 8 are arranged at equal intervals in the first direction X or the second direction Y, but the first conductive lines 8, 8 may not be arranged at equal intervals. The second conductive lines 11, 11 may not be arranged at equal intervals.

[0114] In the frequency selective surface 1 according to the above embodiment, the bonding layer 21 is formed in the groove 5 , but the present invention is not limited to this embodiment. That is, the conductive layer 22 may be formed directly in the groove 5 without providing the bonding layer 21 .

[0115] Furthermore, in the frequency selective surface 1 according to the above embodiment, the case where the blackened layer 25 is provided is shown, but the blackened layer 25 may not be provided.

[0116] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications can be made within the scope of the present disclosure.

[0117] - Industrial Applicability -

[0118] The present disclosure has industrial applicability as a frequency selective surface.

[0119] - Explanation of symbols -

[0120] 1Frequency Selective Surface

[0121] 2 substrates

[0122] 3. Film substrate

[0123] 4 Groove cambium

[0124] 5 Groove

[0125] 6First conductor pattern

[0126] 7Unit 1

[0127] 8. First Conductive Wire

[0128] 9 Second conductor pattern

[0129] 10Unit 2

[0130] 11 Second conductive wire

[0131] 12 Slits

[0132] 21Joint layer

[0133] 22 Conductive layer

[0134] 23. Seed Layer

[0135] 24 Main floor

[0136] 25 Blackening Layer

[0137] 30 third conductor pattern

[0138] 31 Third Conductive Wire

[0139] 40 External control circuit

[0140] 41 Connecting elements

[0141] R1 first area

[0142] R2 Second Area

Claims

1. A frequency selective surface, characterized in that: The frequency selective surface includes a substrate, a first conductor pattern and a second conductor pattern. The substrate is provided with a first region and a second region, There is at least one first conductor pattern, which is arranged in the first area of ​​the substrate and has a plurality of first units consisting of a plurality of first conductive lines. The second conductor pattern is at least one, which is arranged in the second area of ​​the substrate and has a plurality of second units consisting of a plurality of second conductive lines. The plurality of first units are configured such that adjacent first units are in a conductive state with each other. The first conductor pattern is configured such that the overall size of the first conductor pattern is smaller than the wavelength of the electromagnetic wave incident on the frequency selective surface and can reflect the wavelength of the electromagnetic wave. The plurality of second units are configured such that the second conductive lines constituting the adjacent second units are not connected to each other. The second conductor pattern is configured such that a size of one of the second units is smaller than a size of the entire first conductor pattern and is a size capable of transmitting the wavelength of the electromagnetic wave.

2. The frequency selective surface according to claim 1, characterized in that: The first conductor pattern and the second conductor pattern are both configured to have a total light transmittance of more than 70%. The plurality of second conductive lines are each configured to have a line width of less than 10 μm and a length of less than 1 / 50 of the wavelength of the electromagnetic wave.

3. The frequency selective surface according to claim 1, characterized in that: The plurality of second conductive lines are respectively configured to extend along a first direction or a second direction intersecting the first direction. In the first direction, a distance between an end of the second conductive line extending in the first direction and the second conductive line extending in the second direction is set to be greater than 1 μm.

4. The frequency selective surface according to claim 1, characterized in that: The substrate is formed in a film shape.

5. The frequency selective surface according to claim 4, characterized in that: At least one bottomed groove is provided on the outer surface of at least one side of the substrate. The first conductive line and the second conductive line each include a conductive layer buried in the groove portion.

6. The frequency selective surface according to claim 5, characterized in that: A main component of a conductive material constituting the conductive layer of the first conductive wire is the same as a main component of a conductive material constituting the conductive layer of the second conductive wire.

7. The frequency selective surface according to claim 7, characterized in that: The first conductive line and the second conductive line each further include a blackened layer which is stacked on a portion of the conductive layer located on an opening side of the groove portion.

8. The frequency selective surface according to claim 1, characterized in that: A plurality of the first conductor patterns are provided on the substrate. A plurality of the first conductor patterns are arranged on the substrate with a spacing therebetween. A connection element is provided on each of the plurality of first conductor patterns. The connection element is used to electrically connect each of the plurality of first conductor patterns to an external control circuit.

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