JP5243213B2 - Electromagnetic wave interface device and signal transmission system using the same - Google Patents

Description

  The present invention relates to an electromagnetic wave interface device, a sheet-like two-dimensional electromagnetic wave transmission medium, and a method for transmitting and receiving between the sheet-like electromagnetic wave transmission medium.

  Conventionally, an electromagnetic field is present in a region between the opposing conductive sheet bodies, the voltage between the two conductive sheet bodies is changed to change the electromagnetic field, or the change of the electromagnetic field causes the conductive sheet body to change. There has been proposed a technique for performing electromagnetic wave transmission by changing the voltage between them and causing an electromagnetic field to travel in a desired direction. Non-Patent Document 1 below introduces an electromagnetic wave interface device that performs signal transmission / reception and electric power receiving and feeding by electromagnetic wave transmission.

  Also, a signal transmission system that combines a signal transmission device that transmits a signal by changing an electromagnetic field in a gap region sandwiched between a mesh-like conductor portion and a sheet-like conductor portion and a leaching region outside the mesh-like conductor portion. It has been known.

  In the electromagnetic wave transmission sheet used for this signal transmission system, the electromagnetic wave intensity in the leaching region decreases exponentially according to the distance from the sheet. Further, for example, Patent Document 1 below discloses that a resistance or an electromagnetic wave absorber is disposed at an end of a mesh-like conductor portion of an electromagnetic wave transmission sheet to prevent leakage or reflection of electromagnetic waves.

The interface device disclosed in such a document is used by connecting to a communication device with a cable or the like, for example, and has a small unnecessary electromagnetic radiation into the air for the purpose of reducing loss energy. It was.
JP 2007-281678 A Hiroyuki Shinoda et al., "Simultaneous signal and power transmission method using surface microwaves (theory and general support for ubiquitous sensor networks)", IEICE Technical Report Vol.107, No.53 (20070517 ) pp. 115-118

  Conventional interface devices do not have a function of radiating electromagnetic waves into the air or inputting electromagnetic waves irradiated from the air into a communication sheet. For this reason, the interface device used for the communication sheet needs to be used by connecting to a communication device with a cable or the like, for example.

  When it is desired to use the built-in antenna of an existing communication device as it is, it is necessary to place the communication device on or close to the communication sheet. When the communication device is lifted from the communication sheet, there is a problem that the reception intensity becomes small and the communication becomes unstable.

  The present invention has been made in view of the above-described problems, and is an electromagnetic wave interface device that is placed on a communication sheet and locally radiates an electromagnetic wave that can be received by a communication device. The purpose is to provide.

  An aspect of the electromagnetic wave interface device according to the present invention is an electromagnetic wave interface device that inputs / outputs electromagnetic waves to / from a sheet-like electromagnetic wave transmission medium having a mesh-like conductor layer, facing the mesh-like conductor layer side. The electromagnetic wave propagating through the sheet-like electromagnetic wave transmission medium is radiated to a different side of the conductive plate from the sheet-like electromagnetic wave transmission medium.

  In one embodiment of the electromagnetic wave interface device according to the present invention, more preferably, the conductor plate may be a square whose side is approximately half the wavelength of the electromagnetic wave propagating through the sheet-like electromagnetic wave transmission medium.

In one embodiment of the electromagnetic wave interface device according to the present invention, more preferably, the electromagnetic wave interface device includes a conductor plate and a dielectric plate disposed between the conductor plate and the sheet-like electromagnetic wave transmission medium, The plate may be a square whose side is approximately half the wavelength of the electromagnetic wave propagating through the dielectric plate, and the dielectric plate may include a conductor plate inside the outer periphery of the dielectric plate.

  Further, in an aspect of the sheet-like two-dimensional electromagnetic wave transmission medium according to the present invention, any one of the above-described electromagnetic wave interface devices, a mesh-like first conductor layer, a dielectric layer, and a second conductor Layers in order.

  Further, in one aspect of the method for transmitting / receiving to / from the sheet-like electromagnetic wave transmission medium according to the present invention, the method for transmitting / receiving to / from the sheet-like electromagnetic wave transmission medium having a mesh-like conductor layer, The electromagnetic wave interface device according to claim 1, wherein the electromagnetic wave propagating through the sheet-like electromagnetic wave transmission medium is radiated to the outside of the sheet-like electromagnetic wave transmission medium, and the electromagnetic wave emitted from the outside of the sheet-like electromagnetic wave transmission medium is And a receiving step in which the apparatus receives and inputs the sheet-like electromagnetic wave transmission medium.

  ADVANTAGE OF THE INVENTION According to this invention, the electromagnetic wave interface apparatus etc. which are mounted on a communication sheet and radiate | emit the electromagnetic waves of the grade which can be received by a communication apparatus can be provided.

  Embodiments of the present invention will be described below. In addition, embodiment described below is an illustration, Comprising: It is not limited to this and does not restrict | limit the scope of the present invention.

  Also, in the following description, in order to facilitate explanation and understanding, what is a conductor in an electromagnetic wave frequency band used for electromagnetic wave transmission is called a “conductor”, and what is a dielectric in the frequency band. Called “dielectric”. Therefore, it is not directly restricted by, for example, whether it is a conductor, a semiconductor, or an insulator with respect to a direct current. In addition, the conductor and the dielectric are defined by their characteristics in relation to the electromagnetic wave, and do not limit the aspect or constituent material such as whether it is solid, liquid or gas. .

  The electromagnetic wave interface device described in the embodiment absorbs part of the electromagnetic wave flowing in the communication sheet and radiates the electromagnetic wave into the air. Moreover, it has the function to input the electromagnetic waves irradiated to the electromagnetic wave interface device into the communication sheet. The communication sheet has a sheet-like structure in which a thin planar dielectric layer is sandwiched between a mesh-like conductor layer and a flat conductor layer. The mesh period in the mesh-like conductor layer of the communication sheet and the thickness of the dielectric layer are assumed to be smaller than the wavelength of the electromagnetic wave.

  FIG. 1 is a diagram illustrating an outline of an electromagnetic wave interface device 100 according to the embodiment. In FIG. 1, an electromagnetic wave interface device 100 is placed on a two-dimensional communication sheet 120 that propagates electromagnetic waves. The electromagnetic wave interface device 100 typically has such a thin shape that a metal plate and a dielectric are bonded together.

  Further, the electromagnetic wave interface device 100 can radiate the electromagnetic wave propagating through the communication sheet 120 three-dimensionally on its upper surface in the drawing, and has a function of converting the dimension of an electromagnetic wave and a function of deflecting it. An electromagnetic wave radiated from the electromagnetic wave interface device 100 has a radiation shape 110, for example.

  In addition, the communication device 130 above the electromagnetic wave interface device 100 can receive an electromagnetic wave radiated from the electromagnetic wave interface device 100 and communicate with it. The electromagnetic wave interface device 100 is electrically disconnected from a cable or connector and is in a so-called float state, and is not electrically connected to the communication sheet 120 or so-called ground connection.

  In other words, the electromagnetic wave interface device 100 typically does not propagate the two-dimensional electromagnetic wave propagating in the communication sheet 120 by inputting it into a cable or the like one-dimensionally, but typically three-dimensionally the communication sheet 120. And radiates to an upper space substantially orthogonal to

(First embodiment)
Most of the electromagnetic waves propagating through the communication sheet are in the dielectric layer between the mesh-like conductor layer and the flat conductor layer of the communication sheet (the communication sheet is a typical example of a two-dimensional electromagnetic wave transmission medium). To propagate. The function of the electromagnetic wave interface device is to input and output electromagnetic waves to the dielectric layer. As such an electromagnetic wave interface device, there is one that performs input / output of electromagnetic waves to / from a communication sheet using capacitive coupling.

  FIG. 2 is a diagram for explaining an outline of the structure of the communication sheet 120. The communication sheet 120 includes a first protective layer 125 having a predetermined relative dielectric constant, a mesh-like first conductor layer 121, a dielectric layer 122, a plate-like second conductor layer 123, and a second protective layer. 124 in order. On the communication sheet 120, an electromagnetic wave interface device 100 (2) made of a square metal plate having a side length L is placed.

  As shown in FIG. 2, when electromagnetic waves propagate through the dielectric layer 122, if the electromagnetic wave interface device 100 (2) is brought close to the mesh-like first conductor layer 121 side of the communication sheet 120, communication is performed. Capacitively coupled with the sheet 120. A part of the electromagnetic wave flowing through the dielectric layer 122 is sucked out between the mesh-shaped first conductor layer 121 and the electromagnetic wave interface device 100 (2).

  The efficiency with which the electromagnetic wave is sucked out depends on the length of the side of the electromagnetic wave interface device 100 (2), the distance between the mesh-shaped first conductor layer 121 and the electromagnetic wave interface device 100 (2), and the first protective layer 125. Depends on dielectric constant. Further, when the length of one side of the electromagnetic wave interface device 100 (2) is substantially equal to the half wavelength of the electromagnetic wave, resonance occurs and the electromagnetic wave sucking efficiency becomes the highest.

  This phenomenon is considered to be in principle common to the phenomenon of resonance in a microstrip antenna when the length of the radiating element is equal to the half wavelength of the electromagnetic wave.

  An example of a microstrip antenna is also disclosed in, for example, US Pat. No. 3,995,277.

  The bandwidth and directivity capability of such an antenna can be designed and adjusted as appropriate for a particular application.

  In addition, the use of an array of microstrip patches can appropriately design directivity by providing a predetermined scanning angle. However, if the array elements are arranged closer together, the scanning angle can be increased, but the closer arrangement spacing may increase unintentional coupling between the antenna elements, degrading performance. A possible case is also envisaged.

  The electromagnetic wave interface device 100 (2) in which the first conductor layer 121 and the second conductor layer 123 of the communication sheet 120 function as the ground of the microstrip antenna and are brought close to the first conductor layer 121. ) Is considered to perform the same function as the radiating element of the microstrip antenna.

  As shown in FIG. 3, the electromagnetic wave interface device 100 (2) made of a square metal plate with one side length L was placed on the mesh-like first conductor layer 121 of the communication sheet 120. FIG. 3 is a diagram schematically showing a top view when the electromagnetic wave interface device 100 (2) is placed on the communication sheet 120.

  Here, the specifications of the communication sheet 120 are as shown in FIG. 4, and the distance between the electromagnetic wave interface device 100 (2) and the mesh-shaped first conductor layer 121 is 0.1 mm. FIG. 4 is a diagram illustrating the characteristics of the communication sheet 120. Also, electromagnetic waves are input to the communication sheet from the position of the circle 310 in FIG.

  Then, the following (W) was calculated in the region of the electromagnetic wave interface device 100 (2) in FIG.

  In the formula (1), the denominator corresponds to electromagnetic wave energy propagating in the dielectric layer 122, and the numerator corresponds to electromagnetic wave energy absorbed by the first protective layer 125. Therefore, if W shown in Formula (1) is large, it means that the electromagnetic wave propagating in the dielectric layer 122 can be efficiently extracted on the mesh-like first conductor layer 121 layer. There are three simulation frequencies: 2.45 GHz, 5.2 GHz, and 10 GHz.

  The result of calculating W is shown in FIG. FIG. 5 is a diagram showing the electromagnetic wave extraction efficiency W when the length L of one side of the electromagnetic wave interface device 100 (2) is changed.

  As shown in FIG. 5, when the length L of one side of the electromagnetic wave interface device 100 (2) is equal to about half of the wavelength of the electromagnetic wave, the electromagnetic wave flowing through the dielectric layer 122 of the communication sheet 120 is converted into the mesh-shaped first conductor. It can be extracted most efficiently on the layer 121.

  For example, in FIG. 5, each length L corresponding to a point 51 at which W at 10 GHz is maximum, a point 52 at which W at 5.2 GHz is maximum, and a point 53 at which W at 2.45 GHz is maximum is , Each of which corresponds to approximately half the wavelength of the electromagnetic wave in the first protective layer 125.

  The length L of one side of the electromagnetic wave interface device 100 (2) varies somewhat depending on the specifications of the communication sheet 120 to be used, but the length L of one side of the electromagnetic wave interface device 100 (2) is substantially equal to half the wavelength. The most efficient is common in both cases.

(Second embodiment)
FIG. 6 is a conceptual diagram schematically showing the structure of the electromagnetic wave interface device 100 (3) according to the second embodiment. The electromagnetic wave interface device 100 (3) includes a flat dielectric 62 and a conductor plate 61, and has a structure in which the dielectric 62 larger than the conductor plate 61 and the conductor plate 61 are bonded together on the entire outer periphery.

  Although not shown in FIG. 6, the electromagnetic wave interface device 100 (3) may further include a protective layer for protecting the conductor plate 61 on the conductor plate 61. The area of the dielectric 62 is typically larger than the area of the conductor plate 61, and the outer periphery of the conductor plate 61 is entirely contained within the outer periphery of the dielectric 62.

  The thickness of the dielectric 62 is typically smaller than a quarter of the wavelength of the electromagnetic wave in the dielectric 62 (for example, 2 mm). In the microstrip antenna, in order to increase radiation efficiency, it is known to reduce the dielectric constant and increase the thickness of the dielectric.

  However, in the electromagnetic wave interface device 100 (3), it is preferable that the conductor plate 61 is closer to the mesh-shaped first conductor layer 121 in terms of capacitive coupling, and the dielectric material 62 having a higher dielectric constant absorbs electromagnetic waves. Since it becomes easy, it is preferable. That is, it is preferable that the dielectric 62 is thin and has a large dielectric constant. However, it is considered that there exists an optimum dielectric constant range of the dielectric 62 in relation to the amount of electromagnetic waves radiated from the electromagnetic wave interface device 100 (3).

  In FIG. 6, the conductor plate 61 and the dielectric 62 are shown as being square, but the present invention is not limited to this and may be a rectangle or a circle. As shown in FIG. 7, the electromagnetic wave interface device 100 (3) is used by placing the dielectric 62 side on or close to the mesh-like first conductor layer 121 of the communication sheet 120. FIG. 7 is a conceptual diagram illustrating the usage mode of the electromagnetic wave interface device 100 (3). In FIG. 7, the same reference numerals are assigned to the same parts corresponding to those in FIG. 2, and the description thereof is omitted to avoid duplication.

  The electromagnetic wave interface device 100 (3) sucks a part of the electromagnetic wave propagating through the dielectric layer 122 of the communication sheet 120 and radiates it into the air. As a principle regarding the radiation of electromagnetic waves, the same concept as that of a microstrip antenna radiating electromagnetic waves can be applied, and therefore, detailed description is avoided here. In addition, the electromagnetic wave interface device 100 (3) has a function of inputting the electromagnetic wave irradiated to the electromagnetic wave interface device 100 (3) from the air to the dielectric layer 122 of the communication sheet 120.

  When the length L of one side of the conductor plate 61 is substantially equal to the half of the wavelength of the electromagnetic wave in the dielectric 62, the radiation efficiency is highest and the electromagnetic wave irradiated to the electromagnetic wave interface device 100 (3) is communicated. The efficiency input to the sheet 120 is the highest. However, in the electromagnetic wave interface device 100 (3), the length of one side of the conductor plate 61 is not necessarily equal to half of the wavelength of the electromagnetic wave in the dielectric 62, and is appropriately set so as to obtain a desired radiation efficiency or absorption efficiency. Can be designed.

  For example, when a plurality of electromagnetic wave interface devices 100 (3) are provided on the communication sheet 120 and when it is desired to limit the electromagnetic waves sucked out from the single electromagnetic wave interface device 100 (3), other electromagnetic wave interface devices 100 are used. It is good also as the extraction efficiency design which considered the balance with the extraction amount from (3).

  As shown in FIG. 8, when the conductor plate 61 and the dielectric 62 are square, the electromagnetic wave radiated from the electromagnetic wave interface device 100 (3) is linearly polarized. FIG. 8 is a conceptual top view of the electromagnetic wave interface device 100 (3).

  For example, when the conductor plate 61 and the dielectric 62 are not square but shaped as shown in FIG. 9A, the electromagnetic wave radiated from the electromagnetic wave interface device 100 (3) is circularly polarized. FIG. 9 is a diagram illustrating a shape variation of the electromagnetic wave interface device 100 (3). The electromagnetic wave interface device 100 (3) that radiates circularly polarized waves is not limited to FIG. 9A, and various shapes are conceivable.

  In the example shown in FIG. 9A, it is efficient to set the length La of one side, and in the example shown in FIG. 9B, the diameter Lb is approximately half the wavelength of the electromagnetic wave in the dielectric 62. It is preferable from the viewpoint. Reference numerals 910 and 920 denote outer edges of the conductor plate 61.

(Third embodiment)
In the above description, the number of conductor plates 61 is not limited to one, but may be any plurality. Alternatively, the conductor plate 61 may be arranged on the dielectric 62 in an array. For example, by arranging the plurality of electromagnetic wave interface devices 100 (3) in an array, the electromagnetic wave interface device 100 (3) as a whole radiates the electromagnetic wave radiated from the entire electromagnetic wave interface device 100 (3) according to the phase difference value of the electromagnetic waves input to each conductor plate 61. The directivity and strength can be appropriately controlled. That is, the number of conductor plates 61 and the interval between each conductor plate 61 can be appropriately designed so as to have a desired directivity.

  FIG. 10 is a diagram illustrating the communication sheet 120 (2) provided with the electromagnetic wave interface device 100 (4) on which the metal plates 101 and 102 are fixedly arranged in an array on the first protective layer 125. With the electromagnetic wave interface device 100 (4), the communication sheet 120 (2) having high radiation efficiency or absorption efficiency of electromagnetic waves can be obtained. The communication sheet 120 (2) can be electromagnetic radiation having directivity in an arbitrary direction. Note that the communication sheet 120 (2) may further be provided with a protective layer made of resin or the like on the metal plates 101 and 102.

(Fourth embodiment)
In this embodiment, the above-described electromagnetic wave interface device 100 (3) is applied to the wireless LAN system 1100. FIG. 11 is a diagram for explaining a configuration outline of a wireless LAN system 1100 using the electromagnetic wave interface device 100 (3). Since the electromagnetic wave interface device 100 (3) has the same configuration and function as those already described, the description thereof is omitted here to avoid duplication of description.

  The wireless LAN system 1100 is connected to the Internet or the like via a wireless LAN access point 1020. The wireless LAN access point 1020 is connected to the communication sheet 120 via the input / output interface 1010 and inputs electromagnetic waves into the communication sheet 120.

  The electromagnetic wave input from the input / output interface 1010 propagates through the communication sheet 120, and a part of the electromagnetic wave is sucked out from the electromagnetic wave interface device 100 (3) and radiated to the upper space on the drawing three-dimensionally. The radiated electromagnetic wave is received by the communication device 130 (2) and can be communicated.

  The electromagnetic wave radiated from the communication device 130 (2) is received by the electromagnetic wave interface device 100 (3) and input into the communication sheet 120, and is propagated from the input / output interface 1010 to the wireless LAN access point 1020. Communication is possible. That is, it is understood that the electromagnetic wave interface device 100 (3) also has an antenna function.

  The wireless LAN system 1100 can avoid a place where an electromagnetic wave transmitted from an antenna does not reach due to an obstacle such as a wall, a person, or a partition, and can eliminate a place where communication is not stable. It is also possible to avoid a situation in which electromagnetic waves fly to unintended places such as the next room or another floor and cause security problems.

  In the wireless LAN system 1100, an input / output interface 1010 and a wireless LAN access point 1020 are connected by a coaxial cable or the like. For this reason, the communication sheet 120 is preferably used by being placed on a place where a wireless LAN is used, for example, on a desk such as an office or a conference room.

  Wireless LAN access by installing or approaching a mobile device (for example, a notebook computer or PDA) having a wireless LAN function such as IEEE802.11a / b / g in the vicinity of the electromagnetic wave interface device 100 (3) Communication between the point 1020 and the mobile device is enabled.

  Accordingly, it is possible to perform stable communication, and an area where communication can be performed is limited to the upper side of the electromagnetic wave interface device 100 (3), which is preferable. Note that the electromagnetic wave interface device 100 (3) may be used instead of the electromagnetic wave interface device 100, 100 (2), 100 (4), or the communication sheet 120 (2) may be used instead of the communication sheet 120. .

(Fifth embodiment)
Next, an example in which the electromagnetic wave interface device 100 (3) is applied to the RFID system 1200 will be described. FIG. 12 is a schematic diagram illustrating an example in which the electromagnetic wave interface device 100 (3) is applied to the RFID system 1200. In FIG. 12, the same reference numerals are given to the same parts corresponding to those in FIG. 11, and the description thereof is omitted here in order to avoid duplication of explanation.

  In offices and the like, there is a high demand for managing the presence, taking in and out of articles, documents, books, etc. in a shelf. As an existing method for performing this management, there is a method using RFID. An RFID tag is attached to an item to be managed, and an antenna is installed inside the shelf. An antenna is known that detects the presence of an RFID tag by connecting the RFID reader with a coaxial cable.

  As shown in FIG. 12, in the RFID system 1200, an RFID reader / writer 1030 is connected to an input / output interface 1010 with a coaxial cable. On the other hand, the RFID tag 130 (3) is attached to the article to be managed. Then, it is possible to read the presence of the article by bringing the part or attachment surface where the RFID tag 130 (3) is attached close to the surface of the communication sheet 120 or the electromagnetic wave interface device 100 (3) placed on the communication sheet 120 It becomes.

  Since the RFID system 1200 generates a stable tag detection region above the electromagnetic wave interface device 100 (3), it cannot be read unless the RFID tag 130 (3) is brought close to the surface of the communication sheet 120. Can be eliminated.

  Further, when the electromagnetic wave interface device 100 (3) is used, it is possible to read the RFID tag 130 (3) that exists at a certain distance from the communication sheet 120. Further, the RFID system 1200 using the electromagnetic wave interface device 100 (3) can be used not only on a shelf but also on a desk or floor, or attached to a wall.

  This makes it possible to read the tag stably, and the area where the tag can be read is limited to a desired area above the electromagnetic wave interface device 100 (3), which is preferable. Note that the electromagnetic wave interface device 100 (3) may be used instead of the electromagnetic wave interface device 100, 100 (2), 100 (4), or the communication sheet 120 (2) may be used instead of the communication sheet 120. .

  While the electromagnetic wave interface devices 100, 100 (2), 100 (3), 100 (4) and the communication sheet 120 (2) described above reduce leakage of electromagnetic waves from an unintended place of the sheet-like electromagnetic wave transmission medium, It is possible to extract electromagnetic waves locally at a desired location and radiate the electromagnetic waves into a desired three-dimensional space at the desired location.

  In addition, an array configuration is preferable because the intensity and direction of the electromagnetic wave to be radiated can be arbitrarily adjusted by appropriately changing the interval and the number of the array. As a result, for example, a wireless LAN system capable of locally communicating only in a desired area on the desk of the user who owns the electromagnetic wave interface devices 100, 100 (2), 100 (3), 100 (4), etc. It is also preferable because it is easy to do.

  The electromagnetic wave interface devices 100, 100 (2), 100 (3), 100 (4) and the communication sheet 120 (2) described above are not limited to the description in each embodiment, and the configuration thereof is obvious. It is easily understood by those skilled in the art that the operation and processing can be appropriately changed and used within the obvious range.

It is a figure explaining the outline | summary of the electromagnetic wave interface apparatus concerning embodiment. It is a figure explaining the outline | summary of the structure of a communication sheet. It is a top view which shows typically the case where the electromagnetic wave interface apparatus is set | placed on the communication sheet. It is a figure which shows the characteristic of a communication sheet. It is a figure which shows the extraction efficiency W of the electromagnetic wave at the time of changing the length L of the one side of an electromagnetic wave interface apparatus. It is a conceptual diagram which shows typically the structure of the electromagnetic wave interface apparatus concerning 2nd embodiment. It is a conceptual diagram which illustrates the usage condition of an electromagnetic wave interface apparatus. It is a notional top view of an electromagnetic wave interface device. It is a figure which illustrates the shape variation of an electromagnetic wave interface device. It is a figure explaining the electromagnetic wave interface apparatus which has arrange | positioned the metal plate in the array form on the protective layer of a communication sheet. It is a figure explaining the outline | summary of a wireless LAN system structure using an electromagnetic wave interface apparatus. It is a schematic diagram explaining the example which applies an electromagnetic wave interface apparatus to an RFID system.

Explanation of symbols

  100 ... Electromagnetic wave interface device, 120 ... Communication sheet, 121 ... First conductor layer, 122 ... Dielectric layer, 123 ... Second conductor layer.

Claims (5)

An electromagnetic wave interface device for inputting and outputting electromagnetic waves between a top surface, a mesh-like first conductor layer, a dielectric layer, a second conductor layer, and a sheet-like electromagnetic wave transmission medium having a lower surface in order. And
Has a conductive plate provided on the upper surface opposite to the first conductive layer, said conductive plate, the electromagnetic wave propagating through the sheet-like electromagnetic wave transmission medium, to radiation above the sheet-like electromagnetic wave transmission medium An electromagnetic wave interface device characterized by. 2. The electromagnetic wave interface device according to claim 1, wherein the conductor plate is a square whose one side is approximately half the wavelength of the electromagnetic wave propagating through the sheet-like electromagnetic wave transmission medium. The electromagnetic wave interface device further includes a dielectric plate disposed between the conductor plate and the upper surface ,
The electromagnetic wave interface device according to claim 2, wherein the conductor plate is disposed inside an outer periphery of the dielectric plate . The said conductor board inputs the electromagnetic waves radiated | emitted toward the said conductor board to the said sheet-like electromagnetic wave transmission medium, and propagates it to the said sheet-like electromagnetic wave transmission medium. Electromagnetic wave interface device. A sheet-like electromagnetic wave transmission medium having an upper surface, a mesh-shaped first conductor layer, a dielectric layer, a second conductor layer, and a lower surface in order;
An electromagnetic wave interface device having a conductor plate provided on the upper surface facing the first conductor layer,
The signal transmission system, wherein the conductor plate radiates an electromagnetic wave propagating through the sheet-like electromagnetic wave transmission medium above the sheet-like electromagnetic wave transmission medium.

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