WO2007032050A1

WO2007032050A1 - Interface device

Info

Publication number: WO2007032050A1
Application number: PCT/JP2005/016719
Authority: WO
Inventors: Hiroyuki Shinoda; Hiroto Itai
Original assignee: Cell Cross Corporation; The University Of Tokyo
Priority date: 2005-09-12
Filing date: 2005-09-12
Publication date: 2007-03-22

Abstract

In an interface device (601) touching an electromagnetic field and performing communication through variation in electromagnetic field, an internal conductor portion (602) is arranged in the electromagnetic field, an external conductor portion (603) covers the electromagnetic field and the internal conductor portion (602), a path conductor portion (604) connected with the internal conductor portion (602) at at least one end thereof and having a bore is connected with a place different from the one end of the internal conductor portion (602) and communicates with the outside of a region covered by the external conductor portion (603) through the bore thereof, and performs communication through variation in electromagnetic field in response to variation in current in the current path via the external conductor portion (603), the internal conductor portion (602) and the path conductor portion (604).

Description

Specification

Interface device

Technical field

[0001] The present invention relates to an interface device suitable for communicably connecting to a sheet-like signal transmission device by a change in electromagnetic field.

Background art

[0002] Conventionally, a sheet shape (cloth shape, paper shape, foil shape, plate shape, film shape, film shape, mesh shape, etc.) in which a plurality of communication elements are embedded has a wide surface and is thin. The technology relating to the communication device is proposed by the inventors of the present application. For example, in the following documents, a communication in which a plurality of communication elements embedded in a sheet-like member (hereinafter referred to as “sheet-like body”) that does not form individual wiring relays a signal by relaying the signal. A device has been proposed.

Patent Document 1: Japanese Patent Application Laid-Open No. 2004-007448

[0003] Here, in the technology disclosed in [Patent Document 1], each communication element is arranged at the apex of a lattice-like, triangular, or honeycomb-like figure on the surface of the sheet-like body. Each communication element communicates only with other communication elements arranged in the vicinity by utilizing the fact that the potential change generated by the communication element is strong in the vicinity and attenuated and propagated in the distance.

[0004] By sequentially transmitting signals between communication elements by this local communication, signals are transmitted to the target communication element. A plurality of communication elements are divided into hierarchies by the management function, and route data is set in each hierarchy, so that signals can be efficiently transmitted to the final target communication element.

[0005] On the other hand, according to the inventors' research, an electromagnetic field is present in a region between the sheet-like bodies opposed to each other, and the voltage between the two sheet-like bodies is changed to change the electromagnetic field. In addition, a technology has been developed in which the voltage between the sheet-like bodies is changed by the change of the electromagnetic field to advance the electromagnetic field and perform communication.

[0006] In order to detect the voltage between two sheet-like bodies, it is common to directly connect a communication device to both of them or connect a connector to the sheet-like body and connect it to the communication device. It was. Disclosure of the invention

Problems to be solved by the invention

[0007] However, if such a wired connection is made as much as possible, and signals can be transmitted by bringing an external communication device close to the sheet-like body, it is easy for the user to use. Maintenance efficiency is also improved.

[0008] Therefore, there is a strong demand for a new technique for meeting such a demand.

[0009] The present invention meets such a demand, and relates to an interface device suitable for communicably connecting to a sheet-like signal transmission device by a change in electromagnetic field.

Means for solving the problem

In order to achieve the above object, the following invention is disclosed in accordance with the principle of the present invention.

[0011] An interface apparatus according to a first aspect of the present invention is in contact with an electromagnetic field and communicates by a change in the electromagnetic field, and includes an internal conductor part, an external conductor part, and a path conductor part, and is configured as follows.

That is, the internal conductor portion is a conductor in the frequency band of the electromagnetic field, and is disposed in the electromagnetic field when the interface device is in contact with the electromagnetic field.

[0013] On the other hand, the outer conductor portion is a conductor in the frequency band of the electromagnetic field, and covers the electromagnetic field and the inner conductor portion when the interface device is in contact with the electromagnetic field, and is connected to the inner conductor portion at least at one end. And has an aperture.

[0014] Furthermore, the path conductor portion is a conductor in the frequency band of the electromagnetic field, is connected to a location different from the one end of the inner conductor portion, and is connected to the outer conductor portion through an opening of the outer conductor portion. It leads to the outside of the covered area.

Then, communication is performed by the change in the electromagnetic field corresponding to the change in the current flowing in the current path passing through the outer conductor part, the inner conductor part, and the path conductor part.

[0016] It should be noted that the electromagnetic field may be an electromagnetic field having a force or other shape that is typically distributed in a flat plate shape.

[0017] Further, in the interface device of the present invention, the surface of the inner conductor portion on the outer conductor portion side and the surface of the outer conductor portion on the inner conductor portion side can be configured to be substantially parallel. [0018] Further, in the interface device of the present invention, the width of the inner conductor portion is not more than the distance between the surface of the inner conductor portion on the outer conductor portion side and the surface of the outer conductor portion on the inner conductor portion side. Can be configured.

[0019] Further, in the interface device of the present invention, the shape of the outer conductor portion facing the inner conductor portion can be configured to be a cylindrical shape.

[0020] In this way, the inner side of the cylindrical shape becomes a reflection boundary of the electromagnetic wave.

[0021] Further, in the interface device of the present invention, the inner conductor portion has at least one strip shape extending from the center of the disc shape to the circumference of the disc shape, and the inner conductor portion and the outer conductor portion. Can be configured to be connected at the circumference of the disk shape

In particular, the inner conductor portion and the route conductor portion are connected in the vicinity of the center of the disk shape or at a place closer to the circumferential side.

[0023] The interface device of the present invention further includes an insulator, and the insulator is a dielectric in the frequency band of the electromagnetic field, and is a region sandwiched between the outer conductor and the inner conductor. Can be configured to be filled.

[0024] Further, in the interface device of the present invention, when the length of the internal conductor portion is R and the wavelength of the electromagnetic field is defined as:

2 π <λ

Can be configured as follows.

[0025] An interface device according to another aspect of the present invention is in contact with an electromagnetic field and communicates by a change in the electromagnetic field, and includes an internal conductor portion, an external conductor portion, and a communication device, and is configured as follows.

[0026] First, the inner conductor portion is a conductor in the frequency band of the electromagnetic field, and is arranged in the electromagnetic field when the interface device is in contact with the electromagnetic field.

On the other hand, the outer conductor portion is a conductor in the frequency band of the electromagnetic field, and covers the electromagnetic field and the inner conductor portion when the interface device is in contact with the electromagnetic field, and at least one end of the inner conductor portion. Connected. [0028] Further, the communication device is connected to a location different from the one end of the internal conductor portion, and is connected to a location different from the location where the external conductor portion is connected to the internal conductor portion. Communication is performed by changing the voltage in the frequency band of the electromagnetic field.

[0029] An interface device according to another aspect of the present invention is in contact with an electromagnetic field and communicates by a change in the electromagnetic field, and includes an internal conductor portion and an external conductor portion, and is configured as follows.

Here, the inner conductor portion is a conductor in the frequency band of the electromagnetic field, and forms a loop perpendicular to the contacting surface when the interface device is in contact with the electromagnetic field.

On the other hand, the outer conductor portion covers the electromagnetic field and the inner conductor portion when the interface device is in contact with the electromagnetic field.

[0032] Communication is performed by changing the current passing through the inner conductor.

[0033] In the interface device of the present invention, the length of the internal conductor portion is substantially half of the electromagnetic wave length of the electromagnetic field, and at least one end of the internal conductor portion is open and extends from the one end of the internal conductor portion to the other. Since there is a point where the impedance at the electromagnetic wavelength of the electromagnetic field with respect to the outer conductor portion becomes 0 between the paths, the inner conductor portion and the outer conductor portion form a part of the loop.

[0034] From this, even if the inner conductor portion and the outer conductor portion are not directly connected, a so-called capacitor forms a circuit in which current flows through both in the frequency band, thereby creating a loop structure. It is done.

The invention's effect

[0035] According to the present invention, it is possible to provide an interface device suitable for communicably connecting to a sheet-like signal transmission device by a change in electromagnetic field.

Brief Description of Drawings

FIG. 1 is an explanatory diagram showing a schematic configuration of a signal transmission device used in combination with an interface device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state of an interface device having the simplest shape with respect to the signal transmission device of the present embodiment.

FIG. 3 is a signal used in combination with the interface device according to the embodiment of the present invention. It is explanatory drawing which shows schematic structure of a transmission apparatus.

[4] It is an explanatory diagram showing the state of the coordinate system used for the analysis of the signal transmission device.

[5] It is an explanatory diagram showing the strength of the vertical electric field at various locations of the signal transmission device.

6) It is an explanatory diagram for explaining the directivity of the electromagnetic field.

7] FIG. 7 is an explanatory diagram showing a schematic configuration of one embodiment of an interface device having directivity.

FIG. 8 is an explanatory diagram showing a relationship between values of t and w in the interface device.

FIG. 9 is an explanatory diagram showing an outline of the side of the internal conductor connected to the path conductor.

FIG. 10 is an explanatory diagram showing parameters of the shape of the interface device.

FIG. 11 is an explanatory view showing a state of an electromagnetic field generated in a region near the inner conductor portion.

FIG. 12 is an explanatory diagram showing a state of an electromagnetic field in φ mode.

1

13] It is an explanatory view showing a schematic configuration of a circular interface device.

14] It is an explanatory view showing a schematic configuration of a circular interface device.

15] An explanatory diagram showing another embodiment of the interface device.

[16] It is an explanatory diagram showing the relationship of parameters and the state of current and magnetic field.

[17] FIG. 17 is an explanatory diagram showing a technique for performing impedance matching.

圆 18] It is explanatory drawing which shows the experimental parameter of a signal transmission apparatus and an interface apparatus. [19] This is a graph showing the received power when the interface device is gradually separated from the signal transmission device.

FIG. 20 is a graph showing the other received power when the orientation of one of the two interface devices with respect to one mesh is changed.

FIG. 21 is a graph showing the received power of the other when the position of one of the two interface devices is moved.

圆 22] It is explanatory drawing which shows the cross section of other embodiment of an interface apparatus.

[23] FIG. 23 is a cross-sectional view showing the relationship between the interface device and another form of signal transmission device to which the interface device can be connected.

[24] It is an explanatory diagram in the case of performing a wired connection to the signal transmission device.

圆 25] Embodiment in which the first conductor of the signal transmission device is striped instead of meshed It is explanatory drawing which shows.

Explanation of symbols

101 Transmission device

111 First conductor

121 Second conductor

131 Space

141 Leaching area

151 Opposite area

201 Communication circuit

202 loop antenna

203 Dipole type Antesa

601 interface device

602 Inner conductor

603 External conductor

604 Route conductor

605 Insulator part

606 ¾¾,

901 Conductor plate

902 Coaxial cable

903 joint

904 Strip conductor

BEST MODE FOR CARRYING OUT THE INVENTION

[0038] Embodiments of the present invention will be described below. Note that the embodiments described below are for explanation, and do not limit the scope of the present invention. Therefore, those skilled in the art can adopt embodiments in which each of these elements or all of the elements are replaced with equivalent ones, and these embodiments are also included in the scope of the present invention.

[0039] In the following, a signal transmission device having a flat plate shape and an interface device for acquiring signals and sending signals in proximity to the signal transmission devices will be described in order. Explained.

[0040] In the following, in order to facilitate understanding, what is a conductor in the frequency band of electromagnetic waves used for signal transmission is referred to as a "conductor", and what is a dielectric in the frequency band. Called “dielectric”. Therefore, for example, what is an insulator against a direct current may be referred to as a “conductor”.

Example 1

[0041] (Signal transmission device)

FIG. 1 is an explanatory diagram showing a schematic configuration of the signal transmission device according to the present embodiment. Hereinafter, description will be given with reference to this figure.

FIG. (B) is a cross-sectional view of the signal transmission device 101 according to the present embodiment. As shown in the figure, the signal transmission device 101 includes a mesh-like first conductor portion 111 and a flat plate-like second conductor portion 121 substantially parallel to the mesh-like first conductor portion 111.

Here, a region sandwiched between the first conductor portion 111 and the second conductor portion 121 is a narrow space region 131.

In this figure, the region above the first conductor portion 111 is a leaching region 141.

FIG. (A) is a top view of the signal transmission device 101. The first conductor portion 111 of this embodiment is

The second conductor 121 is seen through from the square.

[0045] The mesh repeating unit is equal to the distance between the centers of adjacent squares, which is approximately equal to the length of one side of the square.

[0046] In this embodiment, the gap region 131 and the leaching region 141 are both air forces. One or both of them or a part of them is made of various dielectrics, water or earth, or a vacuum. You may do it.

[0047] The outer shapes of the first conductor portion 111 and the second conductor portion 121 are all sheet-like (cloth-like, paper-like, foil-like, plate-like, film-like, film-like, mesh-like, etc.). It has a thin thickness.

Therefore, for example, when the wall of the room is used as the signal transmission device of the present embodiment, first, a metal foil is pasted as the second conductor portion 121, and then an insulator is sprayed, and then the first conductor is applied. A metal net may be attached as the body portion 111, and an insulating wallpaper may be further attached. Now, in this way, in the signal transmission device 101, attention is paid to the electromagnetic wave mode propagating between the narrow regions 131 sandwiched between the first conductor portion 111 and the second conductor portion 121.

[0050] When the first conductor 111 has a structure that does not have a foil-like opening that is not a mesh, the electromagnetic wave is completely confined in the gap region 131.

[0051] While the force is applied, the first conductor portion 111 has a mesh-like structure and has an opening. With such a shape, the electromagnetic field oozes to a height that is about the same as the mesh spacing. The area where the electromagnetic wave oozes is the leaching area 141.

[0052] The height (thickness) of the leaching region 141 is approximately the same as the repeating unit of the mesh. Actually, the intensity of the electromagnetic wave exponentially attenuates according to the distance of the surface force of the first conductor portion 111.

FIG. 2 is an explanatory view showing the state of the simplest interface device for the signal transmission device of the present embodiment. This figure shows a state in which communication is performed with the signal transmission device 101 by using a loop antenna or a dipole antenna as an interface device. Hereinafter, a description will be given with reference to FIG.

[0054] In the figure, the combination of the communication circuit 201 for transmitting and receiving and the loop antenna 202 connected to the communication circuit in the leaching region 141 existing on the surface of the mesh-shaped first conductor portion 111 is 4 in the figure. Are shown.

[0055] The length of the loop antenna 202 is preferably about half of the wavelength of the electromagnetic wave transmitted by the signal transmission device 101, but communication is possible even if it is larger or smaller than this.

[0056] This figure shows a case where the rectangular loop antenna 202 is arranged in parallel to the surface of the first conductor 111, and the case where it is arranged perpendicular to the surface of the first conductor 111! / Speak.

In addition, this figure shows a case where both ends of the U-shaped loop antenna 202 are terminated by the communication circuit 201 and arranged in parallel to the surface of the first conductor portion 111. It has been done.

[0058] Further, in this figure, a U-shaped loop antenna 202 is connected to the communication circuit 201, and its end portion extends to the opposite side of the communication circuit 201. The case where the first conductor portion 111 is disposed perpendicularly to the surface is shown.

[0059] In addition, a dipole antenna 203 in which the core of the coaxial cable is exposed is used. The interface device used is also shown. In this case, electromagnetic waves can be exchanged between the communication device connected to the coaxial cable and the signal transmission device 101 by bringing the core wire of the dipole antenna 203 close to the first conductor 111. Become.

[0060] These communication circuits 201 can communicate with each other, and the communication device connected to the coaxial cable and the communication circuit 201 can communicate with each other via the signal transmission device 101. Further, although not shown in the figure, when there is a communication device that is directly connected to the first conductor portion 111 and the second conductor portion 121 by wire, communication with the communication device is also possible. In this way, any one-to-one, one-to-N, N-to-one, or N-to-N communication is possible.

[0061] Further, an RFID tag circuit can be used as the communication circuit 201, and this apparatus can be used as a tag reading apparatus, and a sensor can be mounted there. In addition, there is a usage form in which a communication circuit is connected to an external device by wiring, or is connected to a coaxial cable instead of being connected to a communication circuit and connected to an external device.

[0062] It is also possible to supply power by charging the interface device side using microwaves.

[0063] In the above embodiment, the second conductor 121 is a foil-like conductor without an aperture, but the second conductor 121 may be a mesh similar to the first conductor 111. good. FIG. 3 is a cross-sectional view of such a configuration.

[0064] As shown in the figure, the opposing region corresponding to the leaching region 141 is also provided outside the second conductor 121.

There are 151, and electromagnetic waves ooze out here. Therefore, since electromagnetic waves are leached on both the front and back surfaces, signals can be exchanged by bringing the interface device close to either surface.

[0065] Now, the theoretical background of the leaching region 141 will be briefly described below.

In the signal transmission device 101 configured as described above, the electromagnetic wave that travels without “radiating” the electromagnetic wave to the outside of the signal transmission device 101 in the narrow space region 131 (and the leaching region 141 and the opposing region 151 in the vicinity thereof). Mode φ exists.

[0066] Here, the height L of the near field where the electromagnetic field of the same degree as the gap region 131 oozes out and there is no electromagnetic radiation in the distance is About L = ά / (2 π). [0067] Here, in the leaching region 141 and the opposing region 151, when the distance of the surface force of the first conductor portion 1 1 1 and the second conductor portion 121 is z, the amplitude of the leaked electromagnetic wave is approximately e- Attenuates like ^{Z / L.}

[0068] Therefore, the first conductor portion 1 1 1 (or second conductor portion 121) force is also arranged in the range of the distance L, and φ is induced to transmit the signal. Depending on the sensitivity of the interface device, the length d may be less than the distance L. That is, the thickness of the leaching region 141 (or the opposing region 151) can be considered to be about L to d.

[0069] The following is considered in more detail. FIG. 4 is an explanatory diagram showing the state of the coordinate system used for the analysis of the signal transmission device 101. Hereinafter, a description will be given with reference to FIG.

[0070] As shown in this figure, when z = 0, a mesh-shaped first conductor portion 1 1 1 having a repeating unit length d is arranged, and at z = -D, a second conductor portion 121 is arranged. It is assumed that it is arranged. The parts other than the first conductor part 1 1 1 1 and the second conductor part 121 are filled with a dielectric having a dielectric constant ε. The mesh is a square mesh. The origin overlaps the mesh intersection, and the X and y axes are parallel to the mesh.

[0071] At this time, the electromagnetic energy force is localized near the S mesh, and the electric field E of the electromagnetic field is

There is a traveling wave solution in the form of Where E is the z component of the electric field, A, k, k are constants, K x, y, z) is a function with period d in the X direction and y direction, and k = (k, k, 0) Is a wave vector (propagation vector) indicating the traveling direction of the traveling wave.

[0072] That is, for any x, y, z,

l x + d, y, z) = i (x, y, z) = i (x, y, z)

Is established.

[0073] Now, the electromagnetic field containing E is applied to the dielectric!

Δ Ε =-(ω% ² ) Ε

The filling,

+ k = ω / c

It is. [0074] Here, focusing on the electromagnetic field at z> 0, f can be Fourier expanded as follows due to the periodicity of f.

l x, y, z) = ∑ a (m, n exp (2 π J m x / d) exp (2 π J n y / d) g (m, n, z

m, n

Here, m and n are integers.

[0075] When d is sufficiently smaller than the electromagnetic wave length 2 π / d is sufficiently larger than ω / c (m, n) ≠ (0,0), the independence of each component in the family expansion

u (m, n) = exp (2 π j m x / d) exp (2 π j n y / a) g (m, n, z)

Is approximately

Δ u = (-(2 π m / d) ^2- (2 π n / d † + 3 V 3 z ² ) u = 0

That is,

3 V 3 z ² g = (2 π) ² (πι ² + η ² ) / (1 ² _§

Meet. Therefore,

g (m, n, z) ^ B exp, 1 2 π (m + n / z / d)

It is. Where B is a constant. Therefore, for the component of (m, n) ≠ (0,0), the attenuation constant is d / (2π) or less.

Here, the component of (m, n) ≠ (0,0) corresponds to a traveling wave component that has undergone modulation of the period of the mesh structure.

[0077] Further, the component corresponding to (m, n) = (0,0), that is, V, and the traveling wave component after the modulation of the period of the mesh structure, has a wavelength of 2π / (k ² + k ² ) It reaches about ^1/2, but its strength is small. This component is directly related to the term exp (−j (xk + yk).

[0078] Due to such a theoretical background, the first conductor 111 is a mesh-shaped conductor having a square mesh shape of d = 2 [mm], the second conductor 121 is a foil conductor, and the first conductor When the average linear charge density σ = l [C / m] is given to the part 111, the vertical electric field E [V / m] generated is multiplied by the constant 4 π ε.

[0079] Similarly to the above, the first conductor 111 is arranged at ζ = 0, and the second conductor 121 is arranged at z = -D. The origin overlaps the mesh intersection, and the X and y axes are parallel to the mesh.

FIG. 5 is an explanatory diagram showing the strength of the vertical electric field at various locations of the signal transmission device in this case. Hereinafter, a description will be given with reference to FIG. [0081] As shown in the upper three graphs, (x, y) = (0,0), (x, y) = (d / 2, d / 2), (x, y) = ( In any case of d / 2, 0), it can be seen that the vertical electric field is almost zero for the force near z = l [mm]. The vertical electric field at y = l [mm] and z = 0.2 [mm] has a periodic pattern as shown in one graph at the bottom of the figure.

[0082] Thus, when the repeating unit length of the mesh is 2 mm, the leakage of the electromagnetic field is considered to be about lmm, so if the interface device is brought closer than this distance, induction between the electromagnetic field is possible Therefore, it is considered that signals can be transmitted and received.

[0083] Note that the electric field distribution when the second conductor 121 arranged at z = -D has the same mesh structure as the first conductor 111 arranged at z = 0 is based on the principle of symmetry. = The distribution is the same as when the foil-like second conductor 121 is arranged at -D / 2 and the mesh-like first conductor 111 is arranged at z = 0. Therefore, the same conclusion as above can be obtained.

[0084] As described above, it is sufficient to consider the order of d / (2π) to (! / 2 to (!) As the thickness of the leaching region 141 and the opposing region 151. Communication can be achieved by “immersing” the interface in area 151.

Note that the component corresponding to (m, n) = (0,0) is the electromagnetic wave length λ = 2 π / (k ² + k ¹ ) in the communication layer.

x y

Forces that may leach to the extent of ^{/ 2} Near the surface of the communication layer, the intensity of this component is smaller than the other components and can be ignored.

[0086] It should be noted that the mesh may be various polygonal meshes that do not necessarily need to be square repeats. Further, the unit of the mesh need not be limited to the same shape, and may be a different shape as long as it has an appropriate mesh shape. In this case, the value corresponding to the above d can be considered as an average of the sizes of the meshes. If these fundamental periods exist, it can be considered as d.

[0087] In addition, the first conductor portion 111 may be a flat conductor in which a plurality of circular punch holes are formed in the form of a hard cam. In this case, the distance between the centers of the circles corresponds to d above.

[0088] (Interface device)

In the above description, the loop antenna 202 and the dipole antenna 203 are used in the interface device. However, in the following, an interface device that can emit a directional electromagnetic field is proposed. Note that the interface device proposed here is preferably used in combination with the signal transmission device 101 described above, but communication is possible if the interface device can be in contact with an electromagnetic field that transmits a signal. Therefore, the situation where the interface device is used is not limited to the combination with the signal transmission device 101 described above.

FIG. 6 is an explanatory diagram for explaining the directivity of such an electromagnetic field. This will be described below with reference to this figure.

[0091] As shown in this figure, when the angle around the z-axis set perpendicular to the first conductor portion 111 and the second conductor portion 121 of the signal transmission device 101 is Θ, the interface device according to the present embodiment The electromagnetic field φ emitted by, where E is the electric field in the z direction and B is the magnetic field component counterclockwise to the z axis,

1 z Θ

E ^ e (r, z) cos Θ;

B ^ b (r, z) cos Θ;

Θ

However, r ² = (x ² +).

FIG. 7 is an explanatory diagram showing a schematic configuration of one embodiment of an interface device having such directivity. Hereinafter, a description will be given with reference to FIG.

The interface device 601 can be broadly divided into an internal conductor part 602, an external conductor part 603, and a path conductor part 604.

The internal conductor portion 602 is a conductor close to the signal transmission device 101 and has a belt-like shape having a width t. One end of the inner conductor portion 602 is the external conductor portion 603 and the other end is the route conductor portion 604. Are connected to each other.

The outer conductor portion 603 has a box-like structure and covers the inner conductor portion 602. The outer conductor portion 603 has an opening, and the path conductor portion 604 passes through the opening in a non-contact manner.

As a result, a current path of the outer conductor portion 603 to the inner conductor portion 602 to the path conductor portion 604 is established. When a coaxial cable or a signal transmission / reception circuit is coupled to the outer conductor 603 and the path conductor 604 near the opening of the outer conductor 603 and the current flowing therethrough is changed, It will be emitted in the direction of the arrow.

Thus, since the outer conductor 603 covers the inner conductor 602 and the path conductor 604, unnecessary electromagnetic radiation to the outside of the interface device 601 can be prevented. Thus, electromagnetic energy can be exchanged efficiently. Note that portions other than the outer conductor portion 603, the inner conductor portion 602, and the path conductor portion 604 may be filled with a dielectric. The outer conductor portion 603, the inner conductor portion 602, and the route conductor portion 604 may have any internal material as long as the surface thereof is a conductor corresponding to the skin thickness.

[0099] Desirably, the mutually facing surfaces of the outer conductor portion 603 and the inner conductor portion 602 are parallel to each other. The inner conductor portion 602 is also preferably a flat belt, but there are steps or irregularities. Also good.

[0100] When the distance between the opposing surfaces of the outer conductor 603 and the inner conductor 602 is w, t is

It is desirable not to become extremely larger than W. That is, it is desirable that t is about the same as W or t is less than or equal to W.

FIG. 8 is an explanatory diagram showing the relationship between the values of t and w in the interface device 601.

Hereinafter, a description will be given with reference to FIG.

[0102] If t is equal to or less than w, the electromagnetic field generated by the current flowing through the internal conductor 602 will also be generated outside the interface device 601 (the shaded area on the right side of the figure). In combination with the traveling wave mode of the signal transmission device 101, a traveling wave can be induced.

[0103] On the other hand, if t increases and the entire bottom surface of the interface device 601 is covered, no signal can be transmitted or received.

However, if there is a gap in a part of the bottom surface, coupling with the traveling wave mode of the narrow space 131 of the signal transmission device 101 occurs. Therefore, when impedance matching with the cable or communication circuit that drives the interface device 601 is performed, from the opening of the external conductor portion 603 (which is a connection portion between the cable and the interface device 601), the internal interface device 601 In order to reduce the impedance when J is seen by / J, t may be larger than w.

[0105] However, in that case, the ratio of the energy accumulated in the shaded area S on the left side of the figure to the electromagnetic energy generated outside the interface device 601 is increased, and the first conductor portion 111 in contact with the area S, Extra energy loss occurs due to dielectric loss in region S. [0106] Therefore, it is possible to adopt a technique of matching impedance by making the inner conductor portion 602, which does not increase t itself, also have a plurality of thin bands. FIG. 9 is an explanatory diagram showing an outline of the side of the internal conductor 602 connected to the path conductor 604 in such a case.

[0107] As shown in this figure, the inner conductor portion 602 has a fork-like shape, and a plurality of thin strips extend from the path conductor portion 604 to form an outer conductor portion 603 (not shown in this figure). It is configured to be connected to

Further, the length R of the inner conductor portion 602 (the distance between the point where the inner conductor portion 602 is connected to the outer conductor portion 603 and the point where the inner conductor portion 602 is connected to the path conductor portion 604 is R ) and the wavelength of the electromagnetic field should not be extremely smaller than 2π ί?

Here, λ is the wavelength 2 π / (k ² + k ² ) ^V2 of the traveling wave in the signal transmission device 101.

x y

[0110] If 2 π R «λ is satisfied, the ratio of the energy radiated far away to the electromagnetic energy locally generated in the vicinity of the current path is significantly reduced. This is because the ratio of energy loss (due to dielectric loss around the interface, metal resistance) when electromagnetic waves are sent to 101 increases.

[0111] Now, the interface device 601 having such a general shape can be combined with the signal transmission device 101 described above, and a signal transmission device in which two sheet-like conductors are opposed to each other and a hole is locally provided. It can also be combined with a signal transmission device in which a sheet-like dielectric is pasted on one sheet-like conductor. Therefore, the interface device 601 can be applied to various signal transmission devices.

[0112] In the following, the electromagnetic field generated by the interface device 601 will be examined in more detail.

FIG. 10 is an explanatory diagram showing parameters of the shape of the interface device 601. Less than

A description will be given with reference to FIG.

[0114] The length of the inner conductor 602 (hereinafter also referred to as “proximity path” as appropriate) is R, the distance between the inner conductor 602 and the outer conductor 603 is w, and the inner conductor 602 is the path conductor. The length of further stretching beyond the connection point with 604 is m. FIG. 11 is an explanatory diagram showing an electromagnetic field generated in the region S in the vicinity of the internal conductor portion 602 under such conditions.

[0116] Adjust R, m, w, and t so that the impedance of the coaxial cable connected to interface device 601 and the impedance when the inside of interface device 601 is viewed from the portion where the coaxial cable is connected are close. . Here, and when R = λ / 4, there is a place where the reactance component of the impedance crosses zero. Therefore, the length of R is set to a place where it crosses zero.

Next, m, t, and w are adjusted together so that the real part of the impedance becomes the impedance of the coaxial cable.

[0118] Forces that generate such a φ-mode electromagnetic field

1 1

It is explanatory drawing which shows a mode. Hereinafter, a description will be given with reference to FIG.

The rectangles shown in the upper part of the figure and the lower part of the figure correspond to the internal conductor portion 602. The outer conductor portion 603 has a circular shape indicated by a dotted line.

[0120] The upper part of the figure shows the fraction of the magnetic field B in the signal transmission device 101 in the direction of 0 = 0, 180 °.

Θ

It shows the appearance of the cloth. The other direction is a shape obtained by multiplying the distribution of this figure by cos Θ. Near the center, there is also a longitudinal component B in the magnetic field, but it does not play a major role in the present invention.

[0121] A state of current flowing through the first conductor 111 in the signal transmission device 101 is shown. In this way, electromagnetic waves can be emitted simply by guiding the current in one direction, which is convenient.

That is, the electromagnetic field generated by the interface device 601 of this embodiment is a unidirectional magnetic field in the vicinity of the signal transmission device 101 where the overlap with the asymmetric φ-mode electromagnetic field is large.

1

Alternatively, electromagnetic waves are emitted simply by inducing current. Therefore, it is well coupled with the electromagnetic field of the signal transmission device 101 generated by the interface device 601 of the present embodiment.

[0123] In the following, an interface device having another shape is further proposed. 13 and 14 are explanatory diagrams showing a schematic configuration of a circular interface device. Hereinafter, description will be given with reference to this figure.

[0124] The upper part of FIG. 13 is a bottom view of the interface device 601, and the middle part and the lower part are cross sections. FIG. FIG. 14 is a perspective view of the interface device 601.

[0125] As shown in this figure, the outer conductor portion 603 of the circular interface device 601 has a circular plate with a cylindrical side surface, and the opposite side of the circular plate is trimmed. . The internal conductor 602 is connected to the border.

[0126] The internal conductor portion 602 passes through the center of the circle and is connected to the path conductor portion 604 at a location corresponding to the center of the circle.

[0127] The route conductor 604 passes through an opening provided near the center of the outer conductor 603.

[0128] The region covered with the outer conductor is filled with a dielectric and forms an insulator 605.

[0129] In this structure, the central axis of the interface device 601 is also coupled to a standing wave that is symmetrical. The straight φ mode and the axially symmetric mode (electromagnetic waves travel radially from the interface device 601 with equal energy density in all directions. Therefore, it can be considered that stable coupling with little location dependency is possible no matter where the interface device 601 is located in the mesh.

In the present embodiment, the inner conductor portion 602 has a cross shape, the center of the cross character is connected to the path conductor portion 604, and the four ends of the cross character are connected to the external conductor portion 603. You may comprise as follows.

FIG. 15 is an explanatory view showing another embodiment. Hereinafter, description will be given with reference to this figure.

[0132] In the example shown in this figure, the internal conductor 602 and the path conductor 604 are integrated, and one loop-shaped conductor is connected at the connection point 606 of the disk-shaped external conductor 603. RU Thus, while being covered by the outer conductor portion 603 functioning as a shield, a current path may be secured by looping.

In addition, it is possible to consider a form in which the internal conductor 602 is not connected to the external conductor 603. FIG. 16 is an explanatory diagram showing the relationship of parameters in such a case and the state of current and magnetic field. Hereinafter, a description will be given with reference to FIG.

[0134] In the form in which the inner conductor portion 602 is not directly connected to the outer conductor portion 603, the upper part of FIG. As shown in the figure, the length R of the inner conductor portion 602 is preferably about half of the wavelength. The smaller of the width t of the inner conductor 602, the distance w between the inner conductor 602 and the outer conductor 603, and the distance from the contact between the inner conductor 602 and the path conductor 604 to the end point of the inner conductor 602. Impedance matching is achieved by adjusting m.

[0135] The three graphs in the lower part of the figure show the current distribution, magnetic field distribution, and electric field distribution. A further extension of the shape of the graph in Fig. 11 The shape of the graph in this diagram.

[0136] In the example shown in this figure, the length of the internal conductor 602 is set to half the electromagnetic wave length λ. As shown in this figure, when looking at the impedance Ζ at a distance X from the right end of the inner conductor 602 toward the center of the interface device 601, when X = 0, the circuit is open and Ζ = ∞. There is χ = 0 when χ = λ / 4.

Accordingly, this is the same as short-circuiting the inner conductor portion 602 and the outer conductor portion 603 at the point of χ = λ / 4. In other words, in the wavelength measurement, it can be considered that a loop-shaped current path is formed by the inner conductor portion 602 and the outer conductor portion 603 forming a kind of capacitor.

FIG. 17 is an explanatory diagram showing another method for performing impedance matching. The following description will be given with reference to this figure.

[0139] As shown in the figure, the internal conductor portion 602 is cut halfway and is coupled in a capacitive manner.

[0140] In this way, cutting the inner conductor portion 602 halfway has the same effect as connecting a capacitor (typically a capacitor) to the inner conductor portion 602 in series at the entrance of the interface device 601. Bring.

[0141] In these cases, the current path is divided into force. The vicinity of the dividing point functions as a capacitor, and it has been confirmed by experiments that a good connection is possible depending on the frequency band used for communication. Yes. That is, even in such a case, it can be considered that a current loop is formed for the non-DC component!

[0142] The embodiment shown in FIG. 17 has an advantage that even if the outer shape of the interface device 601 is small, impedance matching can be easily performed by dividing.

[0143] In the case of the embodiment shown in Figs. 16 and 17, the electric current flowing through the loop structure (including the division) is also shown. The intensity of electromagnetic wave radiation is determined by the flow and the path length, and the relative positional relationship between the position of the division and the signal transmission device 101 does not directly determine the intensity.

[0144] As described above, in the above-described embodiment, since electromagnetic waves are two-dimensionally confined and communication is performed, the energy force V necessary for information transmission to a certain distance is smaller than that of so-called wireless communication.

[0145] Further, since the range in which energy is diffused is narrow, it is also possible to supply power.

[0146] Further, it is considered that the multipath problem can be avoided, and high-speed communication is possible compared to wireless communication.

[0147] Then, signals can be exchanged between the interface device 601 and the signal transmission device 101 without requiring electrical wiring.

[0148] (Experimental result)

The area covered with the outer conductor 603 of the interface device 601 was filled with a dielectric having a relative dielectric constant of 10, the frequency band was 2.4 GHz, R = 10 mm, and w = 1.6 mm. The connection position m of the path conductor 604 showed good results even when m = 5 mm, but the experimental results when m = Omm are shown below. Further, the mesh period d = 15 mm.

FIG. 18 is an explanatory diagram showing experimental parameters of the signal transmission device 101 and the interface device 601.

[0150] With the specifications in this figure, two interface devices 601 are placed at a center interval of 10 [cm], and a 2.4 [GHz] signal with an amplitude of 1 [V] is transmitted to the other. The received voltage (S12) when the height (position in the z-axis direction) of the other interface device 601 was changed was observed. In addition, a 50 [Ω] cable is connected to both interfaces, and the received voltage (S12) is measured using a network analyzer.

[0151] The specifications in this figure are "line width lmm, mesh opening side 14mm", which corresponds to the case where the mesh repeating unit d is 15mm.

FIG. 19 is a graph showing the results. By about 0.5mm away, the received intensity decreased rapidly.

[0153] In the next experiment, the distance between the two interface devices 601 was set to 6 [cm], and Three orientations of the interface device 601 with respect to the mesh were considered. The graph shows the received voltage S12 when an IV amplitude signal is input for each frequency between 1 GHz and 5 GHz. Connect a 50 Ω cable to the two interfaces and measure the received voltage (S12) using a network analyzer.

FIG. 20 is a graph showing the results. The left end of the horizontal axis of the graph corresponds to lGHz and the right end corresponds to 5GHz. As shown in this figure, signals were observed in a wide band, confirming the effectiveness of the present invention. Each impedance is shown at the bottom of the figure. Since the coupling between the interface device 601 and the signal transmission device 101 is strong, it can be seen that the impedance in the 2.4 GHz band changes depending on the installation direction.

FIG. 21 is a graph when the position of one interface device 601 is moved in the above case. As shown in this figure, a sufficiently strong signal was observed at any location.

Example 2

[0156] Various modifications of the above embodiment will be described below.

FIG. 22 is an explanatory view showing a cross section of another embodiment of the interface device. Less than

A description will be given with reference to FIG.

[0158] The interface device 601 shown in the lower part of the figure has a form corresponding to a combination of the communication device 201 and the loop antenna 202 shown in Fig. 2 covered with an outer conductor 603.

. Open side force of loop antenna 202 Corresponds to inner conductor 602, loop antenna

It can be considered that this corresponds to the outer side conductor portion 603 side force path conductor portion 604 of 202.

[0159] The interface device 601 shown in the middle of the figure adopts a communication device 201 instead of the route conductor portion 604. The communication device 201 also includes an outer conductor portion 603 and an inner conductor portion 60.

The two are directly connected.

[0160] The interface device 601 shown in the upper part of the figure includes an inner conductor portion 602 and an outer conductor portion 60.

3 is connected in the vicinity of the opening, and is similar to the embodiment shown in FIG.

[0161] The interface device 601 of the present invention has an internal conductor 602 that forms part of a loop, and the loop is configured so that the signal transmission device 101 is in contact with the signal transmission device 101. By being perpendicular to the surface of the device 101, the electromagnetic field is tightly coupled. At this time, in order to prevent leakage of the electromagnetic field, an external conductor portion 603 covering these is prepared.

FIG. 23 is a cross-sectional view showing the relationship between the interface device and another form of signal transmission device to which the interface device can be connected. Hereinafter, a description will be given with reference to FIG.

[0163] The interface device 601 shown in the upper part of the figure has two conductor plates arranged opposite to each other.

(A sheet-like conductor may be used. The same shall apply hereinafter.) Of 901, the conductor plate 901 having an opening is disposed near the opening. As in the above embodiment, since electromagnetic waves are confined between the two conductor plates 901, signal transmission is possible, and at the same time, the interface device 601 communicates via an electromagnetic field that oozes from the aperture.

[0164] The interface device 601 shown in the lower part of the figure has the same force as described above. In the present embodiment, the lower conductor plate 901 and the narrower information conductor 901 are arranged. Each of the two conductor plates 901 extends in a direction orthogonal to the drawing, and has a strip shape as a whole. The electromagnetic wave is sealed in the area between the two conductor plates 901, but the width is different, so that the electromagnetic field oozes out when the lower conductor plate 901 is exposed as shown in this figure. . Therefore, using this, the interface device 601 performs communication.

[0165] FIG. 24 is an explanatory diagram in the case of performing a wired connection to the signal transmission device. This will be described below with reference to this figure.

[0166] As shown in the figure, the mesh-shaped first conductor portion 111 of the signal transmission device 101 is connected to the core wire of the coaxial cable 902 immediately before the joint portion 903 so that the impedance is matched so as to match the impedance. Adjust the width. The outer conductor of the coaxial cable 902 is connected to the second conductor portion 121.

[0167] In the example shown in the figure, a strip-shaped conductor portion 904 is disposed on the edge of the first conductor portion 111, and the strip-shaped conductor portion 904 and the second conductor portion 121 are disposed between the edges. In addition, electromagnetic wave absorbers such as collective resistance are arranged to prevent leakage of electromagnetic waves.

FIG. 25 is an explanatory diagram showing an embodiment in which the first conductor portion of the signal transmission device is formed in a stripe shape that is not a mesh shape. [0169] As shown in the figure, the first conductor 111 of the signal transmission device 101 is arranged on the front side of the second conductor 121 in the figure, and the first conductor 111 is concentrated at the root, not in a mesh shape. It has a striped shape. Assuming that the distance between the stripes is d, the degree of leakage of the electromagnetic wave is about d as in the above embodiment, so that the leaching region similar to that in the above embodiment can be formed.

Industrial applicability

[0170] As described above, according to the present invention, it is possible to provide an interface device suitable for communicably connecting to a sheet-like signal transmission device by a change in electromagnetic field.

Claims

The scope of the claims

[1] An interface device (601) that contacts an electromagnetic field and communicates by changing the electromagnetic field,

An inner conductor (602) that is a conductor in the frequency band of the electromagnetic field and is disposed in the electromagnetic field when the interface device (601) contacts the electromagnetic field;

It is a conductor in the frequency band of the electromagnetic field, and covers the electromagnetic field and the inner conductor part (602) when the interface device (601) is in contact with the electromagnetic field, and is connected to the inner conductor part (602) at least at one end. The outer conductor part (603) having a hole, which is a conductor in the frequency band of the electromagnetic field, and is connected to a place different from the one end of the inner conductor part (602), and the outer conductor part (603) A path conductor portion (604) that communicates with the outside of the region covered by the outer conductor portion (603) through an opening having

And the communication by the change in the electromagnetic field corresponding to the change in the current flowing through the current path passing through the outer conductor (603), the inner conductor (602), and the path conductor (604). An interface device (601).

[2] An interface device (601) according to claim 1,

A surface of the inner conductor portion (602) on the outer conductor portion (603) side and a surface of the outer conductor portion (603) on the inner conductor portion (602) side are substantially parallel.

An interface device (601).

[3] An interface device (601) according to claim 2,

The width of the inner conductor portion (602) is such that the surface of the inner conductor portion (602) on the outer conductor portion (603) side, and the surface of the outer conductor portion (603) on the inner conductor portion (602) side. Is less than or equal to the distance

An interface device (601).

[4] An interface device (601) according to claim 3,

The shape of the outer conductor (603) facing the inner conductor (602) is a cylindrical shape.

An interface device (601).

[5] An interface device (601) according to claim 4, The inner conductor portion (602) has at least one strip shape extending from the center of the disc shape to the circumference of the disc shape,

The inner conductor portion (602) and the outer conductor portion (603) are connected at the circumference of the disk shape.

An interface device (601).

[6] An interface device (601) according to claim 1,

An insulator (605) that is a dielectric in the frequency band of the electromagnetic field and fills a region sandwiched between the outer conductor (603) and the inner conductor (602)

An interface device (601), further comprising:

[7] An interface device (601) according to claim 1,

When the length of the inner conductor part (602) is R and the wavelength of the electromagnetic field is λ,

2 π <λ

Does not hold

An interface device (601).

[8] An interface device (601) that contacts an electromagnetic field and communicates by changing the electromagnetic field,

It is a conductor in the frequency band of the electromagnetic field, and when the interface device (601) is in contact with the electromagnetic field, it covers the electromagnetic field and the inner conductor (602) and is connected to the inner conductor (602) at least at one end. External conductor (603),

The inner conductor (602) is connected to a different location from the one end, and the outer conductor (603) is connected to a location different from the location where the inner conductor (602) is connected. An interface device (601) comprising: a communication device that performs communication by changing a voltage between them in a frequency band of an electromagnetic field.

[9] An interface device (601) that contacts an electromagnetic field and communicates by a change in the electromagnetic field.

A conductor in the frequency band of the electromagnetic field, and the interface device is When in contact with an electromagnetic field, the inner conductor (part of a loop perpendicular to the contact surface)

602),

When the interface device (601) is in contact with the electromagnetic field, the outer conductor (603) covers the electromagnetic field and the inner conductor (602).

With

Communication is performed by changing the current passing through the inner conductor (602).

An interface device (601).

An interface device (601) according to claim 9,

The length of the inner conductor portion (602) is substantially half of the electromagnetic wave length of the electromagnetic field, and at least one end of the inner conductor portion (602) is open,

Between the path from the one end to the other of the inner conductor portion (602), there is a point where the impedance in the electromagnetic wave length of the electromagnetic field with respect to the outer conductor portion (603) becomes zero, The inner conductor portion (602) and the outer conductor portion (603) form part of the loop.

An interface device (601).