JP2020178322A - Electromagnetic wave transmission sheet - Google Patents

Abstract

To provide an electromagnetic wave transmission sheet capable of reducing the dispersion of received power due to difference in reception positions on the sheet.SOLUTION: An electromagnetic wave transmission sheet 1 includes a dielectric layer 11, a first conductive layer 12 covering the rear surface of the dielectric layer 11, and a second conductive layer 13 covering the front surface of the dielectric layer 11. The second conductive layer 13 is a combination of a plurality of conductive layers 17 having a mesh-like wiring pattern, and at least part of an end of the mesh-like wiring pattern overlaps with another mesh-like wiring pattern via an insulator.SELECTED DRAWING: Figure 7A

Description

The present invention relates to an electromagnetic wave transmission sheet, and more particularly to an electromagnetic wave transmission sheet capable of reducing dispersion of received power due to a difference in reception position on the sheet.

An electromagnetic wave transmission sheet in which the front and back surfaces of a sheet-shaped dielectric layer (insulator) are sandwiched between two sheet-shaped conductive layers (good conductors) is known. When an electromagnetic wave is input into the electromagnetic wave transmission sheet, the electromagnetic wave propagates inside the induction layer. Here, if one of the conductive layers is formed into a continuous mesh-like pattern, an evanescent wave is generated on the mesh surface. The intensity of the evanescent wave decays exponentially with distance from the mesh-like conductive layer. That is, by forming one of the conductive layers into a mesh shape, it is possible to create a state in which the evanescent wave exudes only in the vicinity of the surface thereof.

By transmitting a signal using an evanescent wave as a medium, it is possible to communicate between a plurality of different positions on the sheet. Further, by rectifying the evanescent wave to direct current, it is possible to extract electrical energy at an arbitrary position on the sheet (see Patent Document 1).

At this time, it is known that by making the mesh-like wiring pattern of the conductive layer into a meander shape, the uniformity of the evanescent wave and the amount of exudation can be improved, and the communication performance and the power feeding performance can be improved (Patent Document 2). ..

Patent No. 4538594 International Publication No. 2017/138475

However, there is room for further improvement in improving the uniformity of the intensity of the evanescent wave in the electromagnetic wave transmission sheet. For example, even when an electromagnetic wave transmission sheet having a meander-shaped pattern as described in Patent Document 2 is used, the inventors depend on the position on the sheet, more specifically, the distance from the electromagnetic wave input point. , I found that the amount of power that can be taken out can vary.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an electromagnetic wave transmission sheet capable of reducing dispersion of received power due to a difference in reception position on the sheet.

The electromagnetic wave transmission sheet according to the embodiment of the present invention has a dielectric layer, a first conductive layer covering the back surface of the dielectric layer, and a second conductive layer covering the surface of the dielectric layer. The second conductive layer is a combination of a plurality of conductive layers having a mesh-like wiring pattern, and at least a part of the end portion of the mesh-like wiring pattern is in the other mesh-like shape via an insulator. It overlaps with the wiring pattern of.
The electromagnetic wave transmission sheet according to the embodiment of the present invention includes a plurality of sheet pieces in which a conductive layer having the mesh-like wiring pattern and a protective layer made of an insulator are laminated, and at least at the end of the sheet pieces. A part overlaps with the other sheet piece.
In the electromagnetic wave transmission sheet according to the embodiment of the present invention, conductive layers having the mesh-like wiring pattern are formed on the front and back surfaces of a protective layer made of an insulator, and the mesh formed on one surface thereof. At least a part of the end portion of the conductive layer having the shape-like wiring pattern overlaps the conductive layer having the mesh-like wiring pattern formed on the other surface.
The electromagnetic wave transmission sheet according to an embodiment of the present invention includes a plurality of protective layers made of an insulator in which a conductive layer having the mesh-like wiring pattern is formed in a part of the region, and is formed on the protective layer. At least a part of the end portion of the conductive layer having the mesh-like wiring pattern overlaps with the conductive layer having the mesh-like wiring pattern formed on the other protective layer.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an electromagnetic wave transmission sheet capable of reducing the dispersion of received power due to a difference in reception position on the sheet.

It is a top view which shows the structure of the conventional electromagnetic wave transmission sheet 1. It is sectional drawing which shows the structure of the conventional electromagnetic wave transmission sheet 1. It is a figure which shows an example of the mesh-like wiring pattern of the 2nd conductive layer 13. It is a figure which shows one configuration example of a power supply port 16. It is a figure which shows one configuration example of a power supply port 16. It is a figure which shows one configuration example of a power supply port 16. It is sectional drawing which shows the typical structure of a coupler 20. It is a top view of the electromagnetic wave transmission sheet 1 which concerns on embodiment of this invention. It is a top view of the electromagnetic wave transmission sheet 1 which concerns on embodiment of this invention. It is sectional drawing of the electromagnetic wave transmission sheet 1 which concerns on embodiment of this invention. It is sectional drawing of the electromagnetic wave transmission sheet 1 which concerns on embodiment of this invention. It is sectional drawing of the electromagnetic wave transmission sheet 1 which concerns on embodiment of this invention. It is sectional drawing of the electromagnetic wave transmission sheet 1 which concerns on embodiment of this invention. It is a top view of the electromagnetic wave transmission sheet 1 which concerns on embodiment of this invention. It is a top view of the electromagnetic wave transmission sheet 1 which concerns on embodiment of this invention. It is a figure which shows the experimental result. It is a figure which shows the experimental result.

Embodiments of the present invention will be described with reference to the drawings. First, with reference to FIGS. 1 to 6, a conventional electromagnetic wave transmission sheet and a communication and power supply method using the conventional electromagnetic wave transmission sheet will be described.

FIG. 1 is a diagram showing a configuration of a conventional electromagnetic wave transmission sheet 1. 1A is a plan view of the electromagnetic wave transmission sheet 1, and FIG. 1B is an enlarged cross-sectional view of the line segment XX of FIG. 1A. As shown in FIGS. 1A and 1B, the electromagnetic wave transmission sheet 1 includes a dielectric layer 11, a first conductive layer 12 that covers the back surface 11R of the dielectric layer 11, a second conductive layer 13 that covers the surface 11S of the dielectric layer 11, and It has a power supply port 16. Preferably, the electromagnetic wave transmission sheet 1 further includes a third conductive layer 14 that covers the end portion 11E of the dielectric layer 11, and a protective layer 15 that covers the second conductive layer 13.

The dielectric layer 11 has a sheet-like shape (spreading as a surface and a thin outer shape, for example, a plate-like, a film-like, a cloth-like, a paper-like, a foil-like, a film-like, a mesh) made of a dielectric material. It is an area of). The material of the dielectric layer 11 may be, for example, air, water, cloth, paper, resin, or the like, or may be vacuum. Further, the thickness of the dielectric layer 11 can be appropriately set according to the dielectric constant of the material used and the frequency of the electromagnetic wave. For example, when the dielectric layer 11 is a foamed polyethylene plate (dielectric constant 2.3) and the electromagnetic wave is in the 2.45 GHz band, the thickness T can be set to about 5 mm in order to improve the input / output efficiency of the electromagnetic wave.

The first conductive layer 12 is a member formed in a sheet shape using a good conductor as a material. For example, the first conductive layer 12 is a metal foil made of copper, aluminum, or the like and having a thickness of about 0.1 mm.

The second conductive layer 13 is a member made of a good conductor and formed in a sheet shape having a mesh-like wiring pattern. For example, the second conductive layer 13 can be created by printing a mesh-like wiring pattern with an ink having conductivity on an insulator sheet (resin sheet or the like) having a thickness of about 0.5 mm. Alternatively, it may be created by making holes in a good sheet-shaped conductor in a predetermined pattern.

FIG. 2 is a diagram showing an example of a mesh-like wiring pattern of the second conductive layer 13. Macroscopically, the wiring pattern shown in FIG. 2 is a mesh pattern in which two substantially parallel linear patterns (striped patterns) are combined at an angle of approximately 90 degrees, whereby a substantially rectangular opening is formed. It is formed regularly. Microscopically, each straight line has a meander shape with a folded pattern. The material of the wiring may be a good conductor, and copper or aluminum is typically used. The entire wiring pattern is electrically connected and is in a continuous state. The line width W and the arrangement pitch of the second conductive layer 13 can be appropriately set according to the frequency of electromagnetic waves and the like. For example, when the electromagnetic wave is in the 2.45 GHz band, the line width W is 0.5 mm or more and 1.5 mm or less, and the mesh pattern arrangement pitch P is 8 mm in order to improve the input / output efficiency of the electromagnetic wave (impedance is 50 Ω). Can be set to a degree.

The third conductive layer 14 is a member made of a good conductor and covers the end portion 11E of the dielectric layer 11. The third conductive layer 14 prevents leakage of electromagnetic waves from the end portion of the electromagnetic wave transmission sheet 1 by short-circuiting the first conductive layer 12 and the second conductive layer 13 at the end portion of the dielectric layer 11. .. The third conductive layer 14 does not necessarily cover the entire end portion 11E of the dielectric layer 11, and is formed in a mesh shape or a stripe shape, for example, to suppress leakage of electromagnetic waves from the end portion of the electromagnetic wave transmission sheet 1. It may be a thing. The material of the third conductive layer 14 may be any good conductor, and copper or aluminum is typically used.

The protective layer 15 includes a first protective layer 15A and a second protective layer 15B. The first protective layer 15A and the second protective layer 15B are made of an insulator and cover the outer surfaces of the first conductive layer 12 and the second conductive layer 13, that is, the surface opposite to the dielectric layer 11. It is a member. The material of the protective layer 15 may be an insulator, and a sheet such as polyethylene or polypropylene is used. By providing the protective layer 15, the durability of the electromagnetic wave transmission sheet 1 can be improved.

FIG. 3 is a diagram showing a configuration example of the power supply port 16. The power supply port 16 is a port for inputting an electromagnetic wave into the electromagnetic wave transmission sheet 1. In the example of FIG. 3, the feeding port 16 is an inverted-F antenna, and the columnar first feeding body 161 and the hollow columnar second feeding body 162, the plate-shaped first feeding plate 163, and the plate-shaped first feeding body 162. It has at least a second feeding plate 164. The materials of the first feeding body 161 and the second feeding body 162, the first feeding plate 163, and the second feeding plate 164 are good conductors, and for example, copper, aluminum, or the like is used. The first feeding body 161 penetrates the dielectric layer 11 and is electrically connected to the first feeding plate 163. The second feeding body 162 is electrically connected to the second feeding plate 164. Here, when the upper direction is the front side and the lower direction is the back side in FIG. 3, both the first power feeding body 161 and the second feeding body 162 project to the front side. The second feeding body 162 is a columnar body having a hollow structure, and is arranged so as to surround the periphery of the columnar first feeding body 161. The first feeding plate 163 is provided apart from the surface of the first protective layer 15A, that is, the first conductive layer 12. The second feeding plate 164 is provided apart from the surface of the second protective layer 15B, that is, the mesh-shaped second conductive layer 13.

A coaxial cable is connected to the power supply port 16 via, for example, an SMA (Sub-Miniature Type A) connector. By connecting an oscillator (not shown) to one end of the coaxial cable, high frequency power is supplied to the power supply port 16 via the coaxial cable. Since the power supply port 16 is capacitively coupled to the electromagnetic wave transmission sheet 1 by the first power supply plate 163 and the second power supply plate 164, the high frequency power supplied from the coaxial cable is transmitted to the electromagnetic wave transmission sheet 1. As described above, since the power supply port 16 is an inverted-F antenna, it is possible to supply power in a small size and with high efficiency.

As shown in FIG. 4, the connection port of the power supply port 16 with the coaxial cable may be provided on the back surface side of the electromagnetic wave transmission sheet 1. That is, when the upper direction is the front side and the lower direction is the back side in FIG. 4, both the first power feeding body 161 and the second feeding body 162 are projected to the back side. In this case, the first feeding plate 163 is provided apart from the surface of the second protective layer 15B, that is, the mesh-shaped second conductive layer 13. The second feeding plate 164 will be provided apart from the surface of the first protective layer 15A, that is, the first conductive layer 12.

In the example of FIG. 3, the end portion of the second feeding plate 164 may be short-circuited with the first conductive layer 12 to form an impedance matching circuit between the feeding port 16 and the electromagnetic wave transmission sheet 1. In the example of FIG. 4, the end portion of the first feeding plate 163 may be short-circuited with the first conductive layer 12 to form an impedance matching circuit between the feeding port 16 and the electromagnetic wave transmission sheet 1. At this time, the end portion of the second feeding plate 164 or the first feeding plate 163 may be short-circuited with the first conductive layer 12 via the third conductive layer 14. As a result, the impedance matching between the power feeding port 16 and the electromagnetic wave transmission sheet 1 is further improved, so that the power feeding efficiency can be improved.

As shown in FIG. 5, the power supply port 16 may be of a clip type in which the front surface and the back surface of the end portion of the electromagnetic wave transmission sheet 1 are sandwiched between two power supply plates. In the example of FIG. 5, the power supply port 16 is provided on the end surface of the first protective layer 15A and the first power supply plate 163 provided on the end surface of the first protective layer 15A. 2 power supply plate 164, a columnar first power supply body 161 electrically connected to the first power supply plate 163, and a hollow columnar second power supply body electrically connected to the second power supply plate 164. 162 and. An insulator 165 may be sandwiched between the first feeding body 161 and the second feeding body 162.

Also in the clip type shown in FIG. 5, the end portion of the second feeding plate 164 may be short-circuited with the first conductive layer 12 to form an impedance matching circuit with the electromagnetic wave transmission sheet 1. As a result, impedance matching with the electromagnetic wave transmission sheet 1 is improved as in the case of the power supply port 16 shown in FIGS. 3 and 4, so that the power supply efficiency can be improved.

The shapes of the first feeding body 161 and the second feeding body 162 shown in FIGS. 3 to 5 are not limited to the columnar shape, and may be various shapes. Further, the shapes of the first feeding plate 163 and the second feeding plate 164 shown in FIGS. 3 to 5 can be various shapes other than a circular shape or a rectangular shape.

When communicating or supplying power using the electromagnetic wave transmission sheet 1, the coupler 20 is used as shown in FIG. 1B. The coupler 20 is electrically connected to the device 30 by a cable L1 or the like. When an antenna (not shown) outputs an electromagnetic wave (typically 2.45 GHz band) to the inside of the electromagnetic wave transmission sheet 1 via the feeding port 16, the coupler 20 is moved to the surface of the electromagnetic wave transmission sheet 1 (mesh-shaped second). When placed on or close to the conductive layer 13 (on the side where the conductive layer 13 is located), the coupler 20 functions as an antenna that receives an evanescent wave and converts it into an electric current. As a result, the device 30 can communicate or receive power. When communicating, an information communication device capable of communicating using electromagnetic waves in the frequency band radiated in the electromagnetic wave transmission sheet 1 as a medium is connected to the coupler 20 as the device 30. When power is supplied, various devices powered by the electric power acquired by the coupler 20 are connected to the coupler 20 as equipment 30.

FIG. 6 is a cross-sectional view showing a typical structure of the coupler 20. The coupler 20 includes a housing 21 made of a good conductor, a dielectric 22 filled in the housing 21, and a plate-shaped internal electrode 23 made of a good conductor. As a good conductor, for example, copper, aluminum, or the like can be used.

The electromagnetic wave RW confined in the dielectric 22 between the housing 21 and the internal electrode 23 propagates to the cable L1 as a signal (shown by the chain line in FIG. 6). In this way, signals can be transmitted and received between the electromagnetic wave transmission sheet 1 and the coupler 20 placed on or close to the surface of the electromagnetic wave transmission sheet 1 using the evanescent wave exuded on the surface of the electromagnetic wave transmission sheet 1 as a medium. If a plurality of couplers 20 are placed or brought close to each other on the surface of the electromagnetic wave transmission sheet 1, signals can be transmitted and received between the plurality of couplers 20 via the electromagnetic wave transmission sheet 1.

At this time, an AC voltage is generated between the housing 21 and the internal electrode 23. By rectifying this voltage change, electric power for operating the device 30 can be obtained.

Next, the structure of the electromagnetic wave transmission sheet 1 according to the embodiment of the present invention will be described with reference to FIGS. 7 to 13. 7A and 7B are plan views of the electromagnetic wave transmission sheet 1. 8 to 11 are views showing one configuration example of the electromagnetic wave transmission sheet 1, and are enlarged cross-sectional views taken along the line segments XX of FIGS. 7A and 7B. 12 and 13 are plan views showing a configuration example of the electromagnetic wave transmission sheet 1. Here, the differences from the conventional electromagnetic wave transmission sheet 1 will be mainly described, and the description of the components similar to the conventional ones will be omitted as appropriate.

In the electromagnetic wave transmission sheet 1 according to the present embodiment, the second conductive layer 13 is formed by combining a plurality of conductive layers 17 having a smaller area than the second conductive layer 13. Each conductive layer 17 has a mesh-like wiring pattern formed of good conductors. Although the mesh pattern composed of straight lines is shown in FIGS. 7 to 13 for the sake of simplification of the description, the present invention is not limited to this, and is configured by a meander shape as shown in FIG. A mesh pattern may be adopted.

The conductive layer 17 is arranged so that at least a part of its end 17E overlaps with another conductive layer 17. For example, as shown in FIG. 7A, the conductive layers 17 can be arranged so that they are superimposed by the width dx at the end 17E appearing in the X direction and by the width dy at the end 17E appearing in the Y direction. The widths dx and dy can be appropriately set to any value of 0 or more. Alternatively, the conductive layers 17 may be superimposed only on the end portion 17E appearing in the X direction or only on the end portion 17E appearing in the Y direction. For example, as shown in FIG. 7B, in the long electromagnetic wave transmission sheet 1 having one side longer than the other side, the conductive layer 17 having a smaller area than the second conductive layer 13 appears in the Y direction. The second conductive layer 13 may be formed by superimposing only 17E by the width dy. In either form, when the conductive layers 17 are superposed on each other, the conductive layers 17 are insulated so as not to be electrically connected to each other. Hereinafter, specific configuration examples of the second conductive layer 13 will be described as Examples 1 to 3.

<Example 1>
As shown in the cross-sectional view of FIG. 8 or 9, a plurality of sheet pieces 19 in which the conductive layer 17 and the insulating layer 18 are laminated are prepared. The insulating layer 18 is a sheet made of an insulator having substantially the same area as the conductive layer 17, and has both a function as an insulating layer and a function as a base material of the conductive layer 17. The second conductive layer 13 is formed by arranging the plurality of sheet pieces 19 so as to be spread over the dielectric layer 11. At this time, the end portions of the sheet pieces 19 are combined so as to overlap the end portions of the adjacent sheet pieces 19. In the portion where the sheet pieces 19 overlap, the insulating layer 18 of the sheet pieces 19 located on the lower side insulates the overlapping conductive layers 17, so that the two are electrically discontinuous.

According to the method of the first embodiment, the electromagnetic wave transmission sheet 1 can be created by laminating sheet pieces 19 smaller than the electromagnetic wave transmission sheet 1, so that there is an advantage that a relatively large electromagnetic wave transmission sheet 1 can be easily created.

<Example 2>
As shown in the cross-sectional view of FIG. 10 and the plan view of FIG. 12, a plurality of sheet pieces 19 in which the conductive layer 17 is laminated only in a part of the insulating layer 18 having substantially the same area as the electromagnetic wave transmission sheet 1 are prepared. That is, regions functioning as the conductive layers 17 are arranged in a predetermined pattern on the plurality of sheet pieces 19 (upper left and lower left views of FIG. 12). In the arrangement pattern of the conductive layer 17, when a plurality of sheet pieces 19 are superposed on the dielectric layer 11 and viewed from the surface side, the conductive layers 17 formed on the plurality of sheet pieces 19 complement each other. It is determined so as to cover the surface of the dielectric layer 11 without gaps (Fig. 12, right figure). That is, it is assumed that the conductive layer 17 is arranged in the other sheet piece 19 in the region where the conductive layer 17 does not exist in the certain sheet piece 19. Further, the conductive layers 17 having a positional relationship in which the end portions 17E are adjacent to each other when viewed from the surface side are assumed to have at least a part of the end portions 17E overlapping each other. The second conductive layer 13 can be formed by laminating the plurality of sheet pieces 19 designed in this way on the dielectric layer 11. Also in this example, since the insulating layer 18 of the sheet piece 19 located on the lower side in FIG. 10 insulates the overlapping conductive layers 17, they are in an electrically discontinuous state.

For example, as shown in FIG. 12, two sheet pieces 19 in which tile-shaped conductive layers 17 are arranged in a checkered pattern are prepared. In the example of FIG. 12, the corner portions of the plurality of conductive layers 17 arranged on the sheet pieces 19 overlap each other, but the corner portions may not necessarily overlap each other. The arrangement pattern of the conductive layer 17 in the two sheet pieces 19 is interpolative, and it is designed so that the surface of the dielectric layer 11 is covered by the conductive layer 17 without a gap when the two sheet pieces 19 are overlapped. Further, the size of the tile-shaped conductive layer 17 is set so that the end portions 17E of the conductive layer 17 overlap with each other when the two sheet pieces 19 are overlapped.

<Example 3>
As shown in the cross-sectional view of FIG. 11 and the plan view of FIG. 13, the sheet piece 19 is formed by laminating the conductive layer 17 on both surfaces of one insulating layer 18 having substantially the same area as the electromagnetic wave transmission sheet 1. Can be used as the second conductive layer 13.

For example, the conductive layer 17 formed on the sheet piece 19 in the first embodiment is laminated on one surface of the insulating layer 18 of the present example, and the other sheet piece 19 is arranged adjacent to the sheet piece 19. By laminating the conductive layer 17 formed in the above on the other surface of the insulating layer 18 of this example, the plurality of sheet pieces 19 of the first embodiment can be combined into one sheet.

Further, the checkered conductive layer 17 formed on the sheet piece 19 in Example 2 is laminated on one surface of the insulating layer 18 of this example, and the checkered conductive layer formed on the other sheet piece 19 is conductive. By laminating the layer 17 on the other surface of the insulating layer 18 of this example, the plurality of sheet pieces 19 of the second embodiment can be combined into one sheet.

In this example, since the insulating layer 18 insulates the conductive layers 17 laminated on the front and back surfaces, the two are electrically discontinuous. In this example, the conductive layer 17 laminated on the surface of the insulating layer 18 is exposed to the outside. In order to protect this, another protective layer may be provided on the outside of the exposed conductive layer 17. In this case, even if a plurality of the sheet pieces 19 of this example are overlapped, the insulating layer 18 of the sheet pieces 19 located on the lower side insulates the overlapping conductive layers 17, so that the two are electrically discontinuous. You can keep the state.

<Effect>
A comparative experiment was conducted to demonstrate the effect of the present invention. The electromagnetic wave transmission sheet 1 having the configurations shown in FIGS. 7B and 9 and the conventional electromagnetic wave transmission sheet 1 (specifications other than the structure of the second conductive layer 13 are the same) are 2.45 GHz at 10 W. The electric power (W) obtained by the coupler 20 was measured by inputting each microwave. At this time, the surface of the electromagnetic wave transmission sheet 1 was virtually divided into blocks of 4 × 6 = 24, and measurements were performed at the representative points of each block. The power supply port 16 was installed in the upper left cell (0,0). In this case, since the coupler 20 cannot be installed in the cell (0,0) (because it interferes with the power supply port 16), the power (W) is not measured in the cell (0,0).

FIG. 14 is an experimental result when a conventional electromagnetic wave transmission sheet 1, that is, an electromagnetic wave transmission sheet 1 in which an electrically continuous mesh pattern is formed on the entire surface of the sheet is used. The mesh pattern had the meander shape shown in FIG. 2, the pitch P was about 8 mm, and the line width W was about 1 mm. In this case, the maximum value of the output was about 1 (W), the minimum value was about 0.2 (W), the average was 0.522 (W), and the variance was 0.037.

FIG. 15 shows the experimental results when the electromagnetic wave transmission sheet 1 having the configurations shown in FIGS. 7B and 9, that is, the electromagnetic wave transmission sheet 1 prepared by combining a plurality of conductive layers electrically insulated from each other is used. is there. A meander-shaped mesh pattern shown in FIG. 2 was formed on each conductive layer, and the pitch P was about 8 mm and the line width W was about 1 mm. Further, the conductive layers were overlapped with each other at the end in the Y direction with a width dy of about 2.5 P (about 20 mm). In this case, the maximum value of the output was about 0.65 (W), the minimum value was about 0.2 (W), the average was 0.363 (W), and the variance was 0.015.

Comparing the two, in the conventional electromagnetic wave transmission sheet 1 in which an electrically continuous mesh pattern is formed on the entire surface of the sheet, the variation in power depending on the receiving position on the sheet is relatively large. On the other hand, in the electromagnetic wave transmission sheet 1 created by combining a plurality of conductive layers electrically insulated from each other, the dispersion of received power is significantly suppressed. As a result, according to the present invention, it has been demonstrated that the dispersion of the output due to the difference in the receiving position on the sheet can be reduced.

(Other embodiments)
The present invention is not limited to the above-described embodiment. That is, one of ordinary skill in the art may make various changes, combinations, sub-combinations, and alternatives with respect to the components of the above-described embodiments within the technical scope of the present invention or the equivalent thereof. For example, the electromagnetic wave transmission sheet 1 including the second conductive layer 13 formed by appropriately combining the components of Examples 1 to 3 is all included in the technical scope of the present invention.

1 Electromagnetic transmission sheet 11 Dielectric layer 11S Front surface 11R Back surface 11E End part 12 First conductive layer 13 Second conductive layer 14 Third conductive layer 15 Protective layer 15A Protective layer 15B Protective layer 16 Power supply port 165 Insulator 161 First Power supply body 162 Second power supply body 163 First power supply plate 164 Second power supply plate 17 Conductive layer 17E End 18 Protective layer 19 Sheet piece 20 Coupler 21 Housing 22 Dielectric 23 Internal electrode 30 Equipment L1 cable

Claims (4)

Dielectric layer and
A first conductive layer covering the back surface of the dielectric layer and
It has a second conductive layer that covers the surface of the dielectric layer, and
The second conductive layer is a combination of a plurality of conductive layers having a mesh-like wiring pattern.
An electromagnetic wave transmission sheet in which at least a part of an end portion of the mesh-like wiring pattern overlaps with another mesh-like wiring pattern via an insulator. A plurality of sheet pieces in which a conductive layer having the mesh-like wiring pattern and a protective layer made of an insulator are laminated are included.
The electromagnetic wave transmission sheet according to claim 1, wherein at least a part of an end portion of the sheet piece overlaps with another sheet piece. Conductive layers having the mesh-like wiring pattern are formed on the front and back surfaces of the protective layer made of an insulator.
Claim 1 in which at least a part of the end portion of the conductive layer having the mesh-like wiring pattern formed on one surface overlaps with the conductive layer having the mesh-like wiring pattern formed on the other surface. The described electromagnetic wave transmission sheet. A plurality of protective layers made of an insulator in which a conductive layer having the mesh-like wiring pattern is formed in a part of the region are included.
Claim that at least a part of the end portion of the conductive layer having the mesh-like wiring pattern formed on the protective layer overlaps with another conductive layer having the mesh-like wiring pattern formed on the protective layer. Item 1. The electromagnetic wave transmission sheet according to item 1.