WO2007037494A1

WO2007037494A1 - Sheet body, antenna device, and electronic information transmission device

Info

Publication number: WO2007037494A1
Application number: PCT/JP2006/319738
Authority: WO
Inventors: Takahiko Yoshida; Masato Matsushita; Haruhide Go; Yoshiharu Kiyohara; Shinichi Sato; Ryota Yoshihara; Kazuhisa Morita; Hiroaki Kogure
Original assignee: Nitta Corporation
Priority date: 2005-09-30
Filing date: 2006-10-02
Publication date: 2007-04-05
Also published as: TWI334670B; TW200731919A

Abstract

A sheet body (10) includes a shield layer (13). The shield layer (13) is formed by a magnetic material. By using it between an antenna element and a conductive member or in the vicinity of the antenna element, it is possible to effectively recover the input impedance of the field type antenna and operate the field type antenna in the vicinity of the conductive member. Furthermore, by setting the real part μ’ of the complex specific permeability of the shield layer (13) to a high value and the permeability loss term tan δμ to a small value, it is possible to suppress the electromagnetic energy loss and increase the radiation efficiency when operating the field type antenna in the vicinity of the conductive member.

Description

Sheet body, antenna device, and electronic information transmission device

Technical field

The present invention relates to a sheet body for wireless communication using an electric field type antenna element in the vicinity of a member having a portion made of a conductive material, and an electronic information transmission apparatus including the sheet body.

The electric field type antenna element in the present invention has a function of an electric field type antenna element used for radio communication of radio wave type, and has a function of a magnetic field type antenna element or a magnetic field type element. It can be switched to a type antenna element.

Background art

FIG. 19 is a cross-sectional view showing a simplified tag 1 of the prior art. The RFID (Radio Frequency IDentification) system is a system used for automatic identification of solids, and basically includes a reader and a transbonder. Tag 1 is used as a transbonder for this RFID system. The tag 1 has a coiled loop antenna 2 that is a magnetic field type antenna that detects magnetic field lines, and an integrated circuit (IC) 3 that performs radio communication using the antenna 2. When tag 1 receives a request signal from the reader, tag 1 transmits the information stored in IC3, in other words, so that the information held in tag 1 can be read by the reader. Composed. Tag 1 is attached to a product, for example, and is used for product management, such as preventing product theft and checking inventory status.

When the tag 1 is used by sticking it to a metal product, and there is a member 4 having a portion made of a conductive material in the vicinity of the antenna 2, an electromagnetic wave signal transmitted and received by the antenna 2 is formed. The magnetic field lines of the magnetic field flow along the surface of the part 4 made of the conductive material. In this case, an eddy current is induced in the portion made of the conductive material of the member 4, and the electromagnetic wave energy is converted to heat energy and lost due to the eddy current loss. If energy is lost in this way, the electromagnetic wave signal is greatly attenuated, and tag 1 cannot communicate wirelessly. In addition, the induced eddy current generates a magnetic field in the opposite direction to the tag's communication magnetic field, thereby canceling the magnetic field. Arise. This phenomenon also prevents tag 1 from communicating wirelessly. Therefore, the tag 1 cannot be used in the vicinity of the member 4 having a portion that also has a conductive material force. In addition, the resonance frequency of tag 1 shifts due to the influence of member 4, and there is a phenomenon that communication cannot be performed at the original communication frequency, so that wireless communication of tag 1 becomes difficult.

FIG. 20 is a cross-sectional view schematically showing a tag 1A as another conventional technique. The tag 1A shown in FIG. 20 is similar to the tag 1 shown in FIG. 19, and the same reference numerals are given to the corresponding parts, and only different configurations will be described. In order to solve the problem of tag 1 in FIG. 19, tag 1A in FIG. 20 has a magnetic absorption plate 7 provided so as to be disposed between member 4 as an article to be attached and antenna 2. Configured to provide. The magnetic absorption plate 7, which is a sheet having a complex relative permeability, has a high permeability material such as sendust, ferrite, and carbon iron, and therefore has a high complex relative permeability and material strength.

The complex relative permeability has a real part and an imaginary part, and the complex relative permeability increases as the real part increases. In other words, a material having a high complex relative permeability has a high real part in the complex relative permeability. If a material with a high real part in the complex relative permeability exists in the magnetic field, the magnetic lines of force pass through the member in a concentrated manner. In the tag 1A using the magnetic field type antenna 2 for detecting the magnetic field lines, the magnetic absorption plate 7 is provided to prevent leakage of the magnetic field to the member 4 having the portion made of the conductive material, and to have the portion made of the conductive material. Even when used in the vicinity of the member 4, wireless communication can be performed by reducing the lines of magnetic force passing through the member 4 having a portion made of a conductive material and suppressing the attenuation of magnetic field energy. Such a tag 1A is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-113142.

As described above, the sheet having complex relative permeability, which has been studied as a metal-compatible technology for antenna communication, is mainly for improving self-inductance. The effect of improving the communication environment by this sheet was the effect obtained when using a coil antenna, which is a magnetic field type antenna for electromagnetic induction communication.

When using a magnetic field type antenna 2 such as a coil antenna in the case of electromagnetic induction communication, such as tag 1 A shown in FIG. 20, a portion made of a conductive material is prevented by preventing leakage of the magnetic field. Force that can enable wireless communication in the vicinity of the member 4 that has the configuration to prevent leakage of such a magnetic field uses an electric field type antenna that detects electric field lines In some cases, it was considered ineffective and was not considered for adoption.

Disclosure of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet body capable of preferably performing wireless communication in the vicinity of a member having a portion made of a conductive material using an electric field type antenna element, an antenna device including the sheet body, and electronic information It is to provide a transmission device.

The present invention relates to an antenna element and a member having a portion made of a conductive material, or an antenna element when performing wireless communication in the vicinity of a member having a portion made of a conductive material using an electric field type antenna element. A sheet body characterized by suppressing a decrease in input impedance of an antenna element by a member provided in the vicinity and having a portion made of a conductive material.

According to the present invention, the sheet body is provided between the electric field type antenna element and the member having the portion made of the conductive material or in the vicinity of the antenna element, so that the portion of the antenna element made of the conductive material cover is provided. When arranged in the vicinity of the member having the member, it is possible to suppress a decrease in input impedance of the antenna element due to the member having a portion formed of a conductive material force.

If the sheet body is not used, the electric field type antenna element hardly operates in the vicinity of a member having a portion made of a conductive material, and cannot be used for wireless communication. This is because the input impedance of the electric field type antenna element is greatly reduced. The decrease in input impedance is caused by a phenomenon in which the antenna element and a member having a portion made of a conductive material are short-circuited at a high frequency. This phenomenon is peculiar to electric field type antennas that do not involve eddy currents. When the input impedance of an electric field type antenna element becomes small, it deviates from the impedance of the communication means that communicates using the electric field type antenna element. The signal cannot be passed between the antenna element of the mold and the communication means. The sheet member can suppress a decrease in input impedance of the antenna element when the antenna element is disposed in the vicinity of a member having a portion made of a conductive material. Therefore, by using a sheet body, it has a portion made of a conductive material using an electric field type antenna element. Even in the vicinity of the member, wireless communication can be suitably performed.

In addition, the present invention provides an electric field type antenna element for performing wireless communication in the vicinity of a member having a portion made of a conductive material, or between an antenna element and a member having a portion made of a conductive material, or an antenna. According to the present invention, a sheet body is provided with an electric field type antenna element and a conductive material. The sheet body is characterized by suppressing loss of electromagnetic energy caused by a member having a portion made of a conductive material. When the antenna element is disposed in the vicinity of the member having the portion made of the conductive material by being provided between the member having the portion made of the material or in the vicinity of the antenna element, the conductive material force is generated. The loss of electromagnetic energy due to the member having the portion can be suppressed. If the sheet body is not used, the electric field type antenna element hardly operates near a member having a portion made of a conductive material and cannot be used for wireless communication. The reason for this is explained by the fact that even an electric field type antenna element consumes electromagnetic energy because electromagnetic coupling occurs between the antenna element and a member having a portion made of a conductive material. A current that is not an eddy current is induced in a member having a portion made of a conductive material by a high-frequency short-circuit, and the change to thermal energy due to resistance loss when this current occurs and the reverse direction generated by the current. The electromagnetic energy is lost due to the cancellation of the communication electromagnetic field by the magnetic field. As a countermeasure against this, the sheet body can suppress the loss of electromagnetic energy when the antenna element is arranged in the vicinity of a member having a portion made of a conductive material. The reason for this is that the short circuit is less likely to occur, and the vicinity of the electric field type antenna element, which is a conductor portion where current is generated, and a member having a portion made of a conductive material due to the magnetic permeability of the sheet body (that is, the interior of the sheet body). This is because the loss of electromagnetic energy can be prevented by allowing the magnetic field to pass through the magnetic field distribution without any attenuation. The impedance adjustment (matching) described above also plays an important role in preventing electromagnetic energy loss. Therefore, by using the sheet member, wireless communication can be suitably performed in the vicinity of a member having a portion made of a conductive material using an electric field type antenna element.

In the present invention, the antenna element includes a dipole antenna, a monopole antenna, and a loop. It includes at least one of an antenna or an antenna loaded with a reactance structure portion.

According to the present invention, by using the sheet body, for example, a dipole antenna having a simple configuration can be used for wireless communication in the vicinity of a member having a portion made of a conductive material. First, the antenna element can be miniaturized by combining a dipole antenna and a sheet. This is coupled with the height of the real part 'of the complex relative permeability of this sheet and the real part ε' of the complex relative permittivity, which adds to the wavelength shortening effect and achieves a much smaller size than conventional products. It is because it can do. The dipole antenna is linear and may be curved or bent and may have a free shape. For example, there is a horseshoe shape. The total length should be λ Ζ2. For example, at 950MHz, a force of about 15.8cm length is added to the wavelength shortening effect of this sheet, and a linear element of about 3-10cm becomes possible. The size that fits in is also possible. Further downsizing is possible, and the range of objects that can be pasted is wide. Since the monopole antenna feeds power between the element on one side of the dipole antenna and the ground plane, the total element length is λ

It can be further downsized with Ζ4. In the case of a loop antenna, when the entire circumference is close to one wavelength, it can be approximated to a structure in which two half-wave dipole antennas are arranged, and can be regarded as an electric field antenna element. These antennas can also preferably perform wireless communication in the vicinity of the communication disturbing member. In addition, these antenna elements may or may not be loaded with a resonance matching portion (reactance matching portion) by an inductance (L) component and a capacitor (C) component.

In addition, the present invention is characterized in that the frequency of electromagnetic waves used for wireless communication is included in a range of 300 MHz to 300 GHz.

According to the present invention, a relatively long wireless communication distance can be realized with a small antenna by using an electromagnetic wave included in a frequency range of 300 MHz to 300 GHz. The range from 300 MHz to 300 GHz includes UHF band (300 MHz to 3 GHz), SHF band (3 GHz to 30 GHz), and EHF band (30 GHz to 300 GHz). Further, the present invention is characterized in that the frequency of electromagnetic waves used for wireless communication is included in the range of 860 MHz to 1 GHz. According to the present invention, the frequency of electromagnetic waves used for wireless communication, since the frequency included below 860MHz above 1GH _z, can be applied to a communication between relatively distant device. Furthermore, communication can be made possible by using a small electric field type antenna having a relatively small electromagnetic wave wavelength used for wireless communication.

Further, the present invention is characterized in that the frequency of electromagnetic waves used for wireless communication is included in the 2.4 GHz band.

According to the present invention, since the frequency of the electromagnetic wave used for wireless communication is a frequency included in the 2.4 GHz band, it can be applied to communication between relatively distant devices. Furthermore, communication can be made possible by using a small electric field type antenna whose wavelength of electromagnetic waves used for wireless communication is relatively small.

Further, the present invention is a sheet body including a shield layer that is a magnetic body. According to the present invention, the sheet used between the antenna element and the member having a portion made of a conductive material or in the vicinity of the antenna element is provided with a shield layer that is a magnetic substance. The shield layer, which is a magnetic material, is effective for suppressing a decrease in impedance caused by a member having a portion made of a conductive material that exists in the vicinity of the electric field type antenna element. A force in which a current is induced by a high-frequency short-circuit in a member having a conductive material force in the vicinity of the antenna element, and a decrease in impedance is observed. The presence of the layer can suppress the impedance drop. This impedance adjustment corresponds only to a specific frequency when the magnetic properties of the magnetic material are frequency-dependent.

In addition, the present invention is characterized by including a shield layer in which the real part μ ′ of the complex relative permeability is equal to or more than the imaginary part μ ″ of the complex relative permeability at the frequency of the electromagnetic wave used for wireless communication.

According to the present invention, the sheet body is provided with a shield layer, and the shield layer has a real part 'of the complex relative permeability at the frequency of the electromagnetic wave used for wireless communication equal to or more than the imaginary part "of the complex relative permeability. Therefore, ≥ μ ". As a result, the real part 'of the complex relative permeability that indicates the ease of collecting the magnetic field is larger than the imaginary part of the complex relative permeability that thermally converts (losses) the magnetic field and has a portion that is made of conductive material force. Input impedance of antenna element by member It is possible to realize a sheet body that can suppress a decrease in dance and more efficiently suppress a loss of electromagnetic energy due to a member having a part made of a conductive material. Furthermore, the real part of the complex relative permeability of the shield layer, together with the real part ε ′ of the complex relative permittivity, has the effect of shortening the wavelength of the antenna element, which also contributes to the miniaturization of the antenna element.

The present invention also provides that the real part μ of the complex relative permeability is 5 or more and the permeability loss term tan δ μ (= μ "/ μ,) force 1 or less at the frequency of the electromagnetic wave used for wireless communication. It is characterized by having a certain shield layer.

According to the present invention, the sheet body is provided with a shield layer, and the shield layer has a real part / ζ ′ of the complex relative permeability of 5 or more at the frequency of the electromagnetic wave used for wireless communication, and the permeability. Loss term tan δ μ force ^ or less. As a result, when the antenna element is disposed in the vicinity of a member having a portion made of a conductive material, a decrease in input impedance of the antenna element due to the member having a portion made of a conductive material can be suppressed. At the same time, it is possible to realize a sheet body that can suppress loss of electromagnetic energy due to a member having a portion made of a conductive material force.

The present invention further comprises a shield layer in which the real part of the complex relative permeability is 20 or more and the permeability loss term tan δ is 0.5 or less at the frequency of the electromagnetic wave used for wireless communication. Features.

According to the present invention, the sheet body is provided with a shield layer, and the shield layer has a real part of the complex relative permeability / ζ ′ of 20 or more at the frequency of the electromagnetic wave used for wireless communication, and the permeability. The loss term tan δ μ is 0.5 or less. As a result, when the antenna element is disposed in the vicinity of a member having a portion made of a conductive material, a decrease in input impedance of the antenna element due to the member having a portion made of a conductive material can be suppressed. In addition, it is possible to realize a sheet body that can suppress a loss of electromagnetic energy due to a member having a portion made of a conductive material force.

In addition, the present invention is characterized by including a shield layer having a real part ε ′ of a complex relative dielectric constant of 20 or more at the frequency of an electromagnetic wave used for wireless communication.

According to the present invention, the sheet body is provided with a shield layer, and the shield layer is a wireless communication device. The real part ε ′ of the complex relative permittivity is 20 or more at the frequency of the electromagnetic wave used for. As a result, when the antenna element is arranged in the vicinity of a member having a portion made of a conductive material, it is possible to suppress a decrease in input impedance of the antenna element due to the member having a portion made of a conductive material. It is possible to realize a sheet body that can suppress a loss of electromagnetic energy of a member having a portion made of conductive material. Also, the antenna can be downsized due to the wavelength shortening effect.

In addition, the present invention is characterized by including a shield layer having an imaginary part ε ″ of a complex relative dielectric constant of 300 or less at the frequency of electromagnetic waves used for wireless communication.

According to the present invention, the sheet body is provided with a shield layer, and the shield layer has an imaginary part ε ″ of the complex relative dielectric constant of 300 or less at the frequency of the electromagnetic wave used for wireless communication. Therefore, when the antenna element is disposed in the vicinity of a member having a portion having a conductive material force, a decrease in the input impedance of the antenna element due to the member having a portion having a conductive material force can be suppressed, and the conductivity can be reduced. It is possible to realize a sheet body capable of suppressing loss of electromagnetic energy caused by a member having a part made of a material, and to provide a conductive layer having conductivity.

According to the present invention, since the sheet body has the conductor layer, the conductor layer made of a conductive material is present in the vicinity of the antenna element, so that the sheet body matches the frequency of the electromagnetic wave used for the wireless communication. , The real part 'and the imaginary part / ζ "of the complex relative permeability of the shield layer or the real part ε, of the complex relative permittivity are adjusted, so that a favorable characteristic of the shield layer can be realized. More suitable wireless communication can be realized in the vicinity of a member having a material force portion.

According to the present invention, the shield layer is made of a material having at least one of a force of a soft magnetic metal, a soft magnetic oxide metal, a magnetic metal and a magnetic acid metal as a magnetic material, or a material containing the same. It is characterized by being.

According to the present invention, the shield layer is a material made of at least one of soft magnetic metal, soft magnetic metal oxide, magnetic metal and magnetic metal oxide, or a material containing the same. Therefore, the shield layer is formed using only these materials, or is realized by dispersing these materials in the binder. With this configuration, the aforementioned characteristics are The resulting shield layer can be formed. Therefore, it is possible to realize a sheet body that achieves the above-described excellent effects.

In addition, the shield layer of the present invention comprises one or more materials selected from the group consisting of ferrite, iron alloy and iron particles as a magnetic material with respect to 100 parts by weight of the organic polymer. It is also characterized in that the material strength is contained with a blending amount of not more than parts by weight.

According to the present invention, the shield layer is obtained by blending a magnetic material with an organic polymer serving as a binder. With such a blend, stable magnetic properties can be obtained, and processability such as cutting and flexibility can be imparted.

Further, the present invention is characterized in that flame retardancy is imparted.

According to the present invention, the sheet body is flame retardant. For example, an electronic information transmission device that performs wireless communication using an antenna element including a tag, a reader, and a mobile phone may be required to be flame retardant. The sheet body can be suitably used for such applications that require flame retardancy.

Further, the present invention is characterized in that thermal conductivity is imparted.

According to the present invention, the environment in which the sheet body is used may be used in the vicinity of a means serving as a heat source, such as a communication means including an IC and a power supply means. Since the heat conductivity of the sheet body is excellent, the heat generated by the heat source means can be released, and the temperature rise of the heat source means is suppressed and exposed to high temperatures. This can prevent performance degradation.

Further, the present invention is characterized in that at least one surface portion has tackiness or adhesiveness.

According to the present invention, since at least one surface portion has adhesiveness or adhesiveness, it can be adhered to another article such as a member having a portion having the conductive material force. Accordingly, the sheet body can be easily used.

The present invention also provides an electric field antenna element having a resonance frequency matched to a frequency used for wireless communication,

An antenna device comprising the sheet body.

According to the present invention, the sheet body has a portion made of an antenna element and a conductive material. It is provided between the materials or in the vicinity of the antenna element. Accordingly, the antenna device can be provided in the vicinity of a member having a portion made of a conductive material cover, and can be used for suitably performing wireless communication using the antenna element and transmitting electronic information. Thus, an antenna device that can be suitably used in the vicinity of a member having a portion made of a conductive material can be realized.

The present invention is also an electronic information transmission device comprising the antenna device.

According to the present invention, it is possible to realize an electronic information transmission device capable of suitably performing wireless communication using an antenna device including an antenna element even when provided in the vicinity of a member having a portion having a conductive material force.

In addition, the present invention is characterized in that it is used as a transbonder that is attached to a densely packed article.

According to the present invention, an electronic information transmission device including a sheet body is used as a transponder of a radio frequency identification (RFID) system such as a tag, for example. Even when the V is installed, the electromagnetic coupling with other transponders in the vicinity and the influence of other transbonders can be suppressed. When multiple transponders are used in a dense state, the other transbonders become members having portions made of conductive materials, and the force that affects wireless communication. The influence of the transbonder can be suppressed and the reading rate by the reader can be improved.

Brief Description of Drawings

Objects, features and advantages of the present invention will become more apparent from the following detailed description and drawings.

FIG. 1 is a cross-sectional view schematically showing a sheet body 10 according to an embodiment of the present invention. FIG. 2 is an enlarged sectional view showing the internal structure of the shield layer 13.

3 is a graph showing the measurement results of the material constants', μ ε ε "of Example 1. FIG. 4 is a cross-sectional view showing the tag 30 including the sheet body 10 in a simplified manner.

FIG. 5 is a perspective view showing the tag 30. FIG. 6 is a cross-sectional view showing an electric field formed in the vicinity of the antenna element 11 in a state where the tag 30 is attached to the communication disturbing member 12.

FIG. 7 is a cross-sectional view showing an electric field formed in the vicinity of the antenna element 11 in a state where the antenna element 11 and the IC tag 17 are arranged in the vicinity of the communication disturbing member 12 without the sheet body 10 interposed.

FIG. 8 is a cross-sectional view showing the configuration of the tag 30 assumed in the simulation for confirming the effect of the sheet 10 when a dipole antenna is used as the antenna element 11.

FIG. 9 is a graph showing a simulation result by the configuration of FIG. 8 and showing a relationship between the frequency and the input impedance of the antenna element.

FIG. 10 is a graph showing the directivity gain, showing the simulation result of the configuration of FIG.

FIG. 11 is a graph showing a simulation result by the configuration of FIG. 8 and showing an absolute gain.

FIG. 12 is a perspective view schematically showing a tag 30 according to another embodiment of the present invention. FIG. 13 is a perspective view showing the beverage 40 to which the tag 30 is attached.

FIG. 14 is a perspective view showing an electronic device 41 in which the tag 30 is built.

FIG. 15 is a plan view schematically showing a tag 30 according to still another embodiment of the present invention. FIG. 16 is a cross-sectional view showing the tag 30 of FIG.

FIG. 17 is a graph showing a simulation result when two tags 30 are placed close to each other as shown in FIG. 15 and FIG.

FIG. 18 is a graph showing a simulation result when two tags that are not provided with the sheet member 10 in the tag 30 shown in FIGS. 15 and 16 are similarly arranged close to each other.

FIG. 19 is a cross-sectional view schematically showing a tag 1 which is a conventional technique.

FIG. 20 is a cross-sectional view schematically showing a tag 1A as another conventional technique.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing a sheet body 10 according to an embodiment of the present invention. The sheet body 10 is provided between the electric field type antenna element 11 and a member 12 having a portion made of a conductive material (hereinafter referred to as “communication blocking member”) 12 or in the vicinity of the antenna element. In the wireless communication in the vicinity of the communication disturbing member 12, the sheet body 10 suppresses the deterioration of the communication environment by the antenna element 11 due to the communication disturbing member 12. Here, the vicinity means a close position that affects the communication environment of the wireless communication by the antenna element.

The bad communication environment includes a decrease in the input impedance of the antenna element 11 and a loss of electromagnetic energy. Further, the resonance frequency of the antenna element 11 may shift due to the influence of the communication disturbing member 12. Therefore, the sheet body 10 is the sheet body 10 that suppresses a decrease in input impedance of the antenna element 11 due to the communication interference member 12 and suppresses a loss of electromagnetic energy due to the communication interference member 12. The resonance frequency may be adjusted by the sheet body 10 or may be adjusted by a matching circuit (reactance loading portion).

The antenna element 11 is not particularly limited as long as it is an electric field type antenna element. In this embodiment, the antenna element 11 is a dipole antenna, a monopole antenna, or a loop antenna. In the case of a loop antenna, an electric field type behavior is exhibited when the perimeter is one wavelength or near one wavelength. Here, there is one wavelength! /, The 1Z2 wavelength of the dipole antenna and the 1Z4 wavelength of the monopole antenna are effective meanings. Including the case of length.

In the present invention, the electric field type antenna element means the function of the electric field type antenna element except for the function of the electromagnetic induction type magnetic field type antenna element, that is, only the function of detecting the magnetic field lines. Any device having a function of detecting electric lines of force may be used. For the electric field type antenna element, an element that uses only the function of detecting electric lines of force, an element that uses both the function of detecting electric lines of force and the function of detecting lines of magnetic force, and electric lines of force An element that alternately switches between a function of detecting the magnetic field and a function of detecting the lines of magnetic force is included. In the present invention, a conductive material as a communication blocking member is a material including only a conductive material and a material including a conductive material. This conductive material includes, for example, conductive materials such as metals, Si-based materials, graphite sheets, oxides such as ITO and ZnO, liquids such as water, chemicals, and oils, water-containing materials, and the like. A material that has a level of conductivity that can cause short-circuiting, coupling, or interference with the device at high frequencies. The conductive material is a conductive material, such as a metal, which has a resistivity of 10 " ⁶ Ωcm or more and less than 10 ^_1 Ωcm, a relatively low resistivity material, a liquid such as water and seawater, and a semiconductor In other ^words , the resistivity is ^10_1 Ωcm or more and 10 ⁶ Ωcm or less, and the resistivity is relatively high!

The member having a portion made of a conductive material includes at least a member made of a conductive material, and includes a member made entirely of a conductive material force and a member made only of a conductive material. Therefore, this member is a member that is at least partially conductive. For example, only the surface portion may have conductivity, or the whole may have conductivity. Other antenna bodies, other antenna elements, metal plates, metal containers, housings, shield materials, conductive fibers, containers containing liquids, test tubes containing liquids, containers containing pastes, etc. including.

The antenna element 11 and the sheet body 10 may be attached via an adhesive layer or directly provided without an adhesive layer. The adhesive layer is a layer having adhesiveness or adhesiveness and made of a bonding agent, and the antenna element 11 and the sheet body 10 are attached by the adhesiveness or adhesiveness. The bonding agent is generally a dielectric, and the adhesive layer is also a dielectric layer. The structure directly provided may be a structure in which at least one of the antenna element 11 and the shield layer 13 is adhered to each other by the adhesiveness or adhesiveness of the antenna element 11 and the shield layer 13, and the antenna element 11 is attached to the shield layer 13. The shield element 13 may be coated, welded, fixed, embedded, or sandwiched between the antenna element 11 or the support body that supports the antenna element 11. Alternatively, it may be added by spraying or the like. The support is, for example, a PET film.

The sheet body 10 is a sheet body having an effect of shielding an electromagnetic field, and is a sheet body having an effect of shielding an electromagnetic field formed by an electromagnetic wave used for wireless communication. Tsuma In other words, the sheet is used to reduce the electromagnetic field from the antenna element 11 to reach the communication disturbing member 12 in order to suppress the influence of impedance reduction or the like caused by the communication disturbing member 12 in the vicinity of the antenna element 11. Although it is expressed as shielding here, it includes not only complete shielding but also partial shielding and passing through a magnetic field. Therefore, the sheet body 10 is configured to block electromagnetic waves used for wireless communication, thereby suppressing the above-described adverse effects of the communication environment.

The electromagnetic wave to be blocked may be an electromagnetic wave used for any purpose. The frequency of the electromagnetic wave to be blocked is determined by the use of the electromagnetic wave. The electromagnetic waves to be blocked are, for example, electromagnetic waves used in RFID systems, and are electromagnetic waves having a frequency included in the range of 860 MHz to 1 GHz belonging to the UHF band (hereinafter referred to as “high MHz band”). More specifically, it is an electromagnetic wave having a frequency within the range of 950 MHz to 956 MHz in Japan.

The frequency of the electromagnetic wave to be blocked is an exemplification, and a configuration for blocking electromagnetic waves having a frequency other than the illustrated frequency is also included in the present invention. The material characteristics of the shield layer change little in these frequency ranges, and the numerical values in the present invention can be used as they are.

In addition, electromagnetic waves with a frequency in the 4 GHz band may be targeted for blocking. 2. The 4 GHz band is a frequency range from 2400 MHz to less than 2500 MHz. The frequency of electromagnetic waves used in RFID systems is in the range of 2400MHz to 2483.5MHz. The frequency of the electromagnetic wave to be blocked is not particularly limited, but any single or plural frequencies can be selected, including a range from 300 MHz to 300 GHz. The range from 300 MHz to 300 GHz includes UHF band (300 MHz to 3 GHz), SHF band (3 GHz to 30 GHz), and EHF band (30 GHz to 300 GHz). The sheet body 10 is configured as a laminated body in which the shield layer 13, the conductor layer 14, and the adhesive agent layer 15 are laminated. The shield layer 13 is a layer for blocking electromagnetic fields, and is a layer for blocking electromagnetic waves.

The conductor layer 14 is a layer made of a conductive material, and is made of copper in this embodiment. Since the conductor layer 14 may affect the antenna element 11 as a communication disturbing member, This effect is suppressed by the layer 13. Conductor layer 14 may also function as an intermediate antenna. In order to improve the impedance of the conductor layer 14, it is possible to make slits, to divide them, or to distribute the conductivity. The size of the conductor layer 14 is not limited.

The sticking agent layer 15 is a layer composed of a sticking agent cover for sticking the sheet body 10 including the shield layer 13 to an article. The sticking agent includes at least one of a pressure-sensitive adhesive and an adhesive, and has a bonding force due to stickiness or adhesiveness.

The shield layer 13, the conductor layer 14, and the sticking agent layer 15 are laminated in this order from one side in the thickness direction to the other side. A binder layer 16 made of an adhesive or an adhesive is interposed between the shield layer 13 and the conductor layer 14 or in the vicinity of the antenna element. By this binder layer 16, the shield layer 13 and the conductor layer 14 are mutually connected. Are combined. The adhesive layer 15 is bonded to the conductor layer 14 by its own adhesive force or adhesive force. Hereinafter, the shield layer 13, the conductor layer 14, the adhesive layer 15 and the binder layer 16 are collectively referred to as the constituent layers 13 to 16.

The conductor layer 14 and the adhesive layer 15 are not necessarily required constituent materials, but the shield layer 13 is attached to the communication blocking member 12 via the binder layer 16, or directly without the binder layer 16. It is also possible to do. Each of the constituent layers 13 to 16 of the sheet body 10 may be multi-layered. For example, the shield layer 13 may be multi-layered to give the magnetic permeability a gradient, or even a single layer to give the magnetic permeability a gradient. Can be used.

The thickness dimension of each layer 13 to 16 and the total thickness dimension of the sheet body 10 are not particularly limited. However, for example, in this embodiment, the thickness dimension of the shield layer 13 is 1 m or more and 10 mm. The thickness dimension of the conductor layer 14 is ΙΟθΑ (1 X 10 ^_8 m) or more and 500 0 m or less, the adhesive layer 15 is 1 m or more and lmm or less, and the binder layer 16 is 1 The total thickness of the sheet 10 is 3 μm or more and 12 mm or less. The sheet body 10 can be reduced in overall thickness dimension, and the layers 13 to 16 are made of the material force as described above, and have flexibility. Therefore, the sheet body 10 can be freely deformed.

The shield layer 13 blocks electromagnetic waves used for wireless communication by selecting material characteristic values including complex relative permeability and complex relative permittivity. Real number of complex relative permeability The larger the part 'is, the more the magnetic field lines pass through, and the higher the shielding effect of the electromagnetic wave, the imaginary part of the complex relative permeability "and the permeability loss term tan δ μ (= μ ^, ' / μ ') The smaller the, the smaller the loss of magnetic field energy, so the smaller the real part 'of the complex relative permeability, the more preferable the imaginary part μ "of the complex relative permeability and the permeability loss term tan δ μ, the better. . In addition, the larger the real part ε, of the complex relative permittivity is, the more the electric force lines pass through, and the higher the electromagnetic wave blocking effect is. The smaller the imaginary part ε "of the complex relative permittivity is, the smaller the electric field energy is. Therefore, the larger the real part ε 'of the complex relative permittivity, the better. The smaller the imaginary part ε "of the complex relative permittivity, the better.

In the present invention, the real part 'and imaginary part' of the complex relative permeability and the real part ε 'and imaginary part ε "of the complex relative permittivity are values corresponding to the frequency of the electromagnetic wave used for wireless communication. The frequency of electromagnetic waves used for wireless communication is not particularly limited, but may be in the range of 300 MHz to 300 GHz including UHF, SHF and EHF bands, for example 860 MHz to 1 GHz. The following high MHz band or 2.4 GHz band frequency may be used.

In the present embodiment, the shield layer 13 is configured such that the real part μ of the complex relative permeability and the imaginary part μ ″ of the complex relative permeability are μ′≥μ ”with respect to the electromagnetic wave used for wireless communication. Therefore, the real part / ζ ′ of the complex relative permeability is equal to or greater than the imaginary part “of the complex relative permeability. The shield layer 13 has a complex relative permeability with respect to electromagnetic waves used for wireless communication. The real part μ is 5 or more and the permeability loss term tan δ μ is 1 or less, and the shield layer 13 has a real part / ζ ′ of complex relative permeability for electromagnetic waves used in wireless communication. For the electromagnetic wave used for wireless communication, which is preferably 10 or more and the permeability loss term tan δ μ is 1 or less, the real part 'of the complex relative permeability is 20 or more and the permeability More preferably, the magnetic loss term tan δμ is 0.5 or less.

In the present embodiment, the shield layer 13 has a real part ε ′ of the complex relative permittivity of 20 or more and an imaginary part ε ″ of the complex relative permittivity of 300 or less with respect to the electromagnetic wave used for wireless communication. And the dielectric loss term tan δ ε (= ε V ε ') is 15 or less.

FIG. 2 is an enlarged sectional view showing the internal structure of the shield layer 13. Figure 2 shows an illustration. For the sake of simplicity, the hatching of the magnetic powder 21 and the magnetic fine particles 22 is omitted. O The shield layer 13 is made of a magnetic material for the binder 20 in order to obtain the material characteristic values as described above. It is formed by mixing powder (hereinafter referred to as “magnetic powder”) 21 and fine particles (hereinafter referred to as “magnetic fine particles”) 22 made of a magnetic material. The shield layer 13 contains magnetic powder 21 and magnetic fine particles 22 as magnetic materials. In the present embodiment, the binding material 20 is made of a polymer, for example, a non-norogen-based polymer, or a non-halogen-based mixed material obtained by mixing a non-norogen-based polymer and another polymer. The specific examples of the binder are merely examples, and are not limited to non-halogen polymers.

A halogen-based polymer can also be used as the binder 20. As for the binder 20, any material such as polymer (resin, TPE, rubber) dies, oligomers, etc. can be used, regardless of whether they are organic or inorganic, and does not depend on the degree of polymerization. Non-halogen materials can be preferably used from the environmental viewpoint. For forming a sheet, a polymer material is suitable. For example, the materials exemplified below can be preferably used, but the types of materials not mentioned in the examples, materials with different blending methods, and alloyed materials can be used. All possible materials can be used.

As the material of the binder 20, various organic polymer materials can be used, and examples thereof include rubber, thermoplastic elastomer, and polymer materials containing various plastics. Examples of the rubber include natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, ethylene propylene rubber, ethylene vinyl acetate rubber, butyl rubber, halogenated butyl rubber, chloroprene rubber, -tolyl rubber, acrylic rubber, and ethylene acrylic rubber. Synthetic rubber such as rubber, epichlorohydrin rubber, fluoro rubber, urethane rubber, silicone rubber, chlorinated polyethylene rubber, hydrogenated-tolyl rubber (HNBR), their derivatives, or these modified by various modification treatments Things. Liquid rubber is also acceptable.

These rubbers can be used alone or in combination. In addition to vulcanizing agents, rubbers are blended as appropriate with rubber additives such as vulcanization accelerators, anti-aging agents, softeners, plasticizers, fillers, and colorants. be able to. This In addition to these, arbitrary additives can be used. For example, in order to control the dielectric constant and conductivity, a predetermined amount of dielectric (carbon black, graphite, titanium oxide, etc.) is used for impedance matching to unwanted electromagnetic waves generated in electronic equipment, which is one of the applications. Depending on the temperature environment, materials can be designed and added. Furthermore, processing aids (lubricants, dispersants) may be appropriately selected and added.

Thermoplastic elastomers include, for example, chlorinated polyethylenes such as chlorinated polyethylene, ethylene copolymers, acrylics, ethylene acrylic copolymers, urethanes, esters, silicones, styrenes, amides, etc. Various thermoplastic elastomers and their derivatives are mentioned.

Furthermore, as various plastics, for example, polyethylene, polypropylene, AS resin, ABS resin, polystyrene, polyvinyl chloride, polychlorinated resin such as polyvinylidene, polyvinyl acetate, ethylene vinyl acetate copolymer, Fluorine resin, silicone resin, talyl resin, nylon, polycarbonate, polyethylene terephthalate, alkyd resin, unsaturated polyester, polysulfone, urethane resin, phenol resin, urea resin, epoxy resin, polyimide resin Examples thereof include thermoplastic resins such as fats and biodegradable resins, or thermosetting resins and derivatives thereof. As these binders, low molecular weight oligomer types and liquid types can be used. Any material can be selected as long as it becomes a sheet after being molded by heat, pressure, ultraviolet rays, radiation, electron beam, air drying, a curing agent, or the like.

The magnetic powder 21 is a flat soft magnetic metal powder, dispersed so as not to contact each other, and oriented so as to extend perpendicular to the thickness direction of the shield layer 13. The magnetic powder 21 has a substantially disk shape, the average thickness dimension is, and the average outer diameter in the direction perpendicular to the thickness direction is 55 m. The magnetic fine particles 22 are fine particles smaller than the thickness dimension of the metal powder, and are configured such that at least the outer surface portion has non-conductivity throughout and has low conductivity. The average outer diameter of the magnetic fine particles 22 is: m.

As the binding material 20 forming the shield layer 13, for example, HN BR, which is a hydrogenated NBR rubber, is used. The magnetic powder 21 is made of Sendust, which is an alloy of iron, silicon and aluminum (FeSi-A1), for example. In addition, magnetic fine particles suppress the overall conductivity. It has corrosion resistance, for example, acidite (magnetite) force. The shapes, dimensions, and materials described above are merely examples and are not intended to be limiting.

As long as the shield layer 13 has an appropriate complex relative permeability and complex relative permittivity, the material configuration is not particularly limited. As in this example, a binder (20) in which soft magnetic powder 21 and Z or magnetic fine particles 22 are dispersed can be used to form a magnetic material (metal oxide, ceramics, dollar-yura thin film, flickering, metal organic compound). It is also possible to use a magnetic layer or the like as the shield layer 13 as it is.

Soft magnetic powder 21 and / or soft magnetic powder 22 materials include Sendust (Fe—Si—A1 alloy), Permalloy (Fe—Ni alloy), Cemented steel (Fe—Cu—Si alloy), Fe—Si alloy, Fe—Si—B (—Cu—Nb) alloy, Fe—Ni—Cr—Si alloy, Fe—Cr—Si alloy, Fe—Al—Ni—Cr alloy, Fe—Ni—Cr alloy, Fe-Cr-Al-Si alloys, Fe-based alloys, Co-based alloys, Si-based alloys, Ni-based alloys, amorphous metals, and the like. It is also possible to use ferrite or pure iron as the soft magnetic powder material. Examples of ferrites include soft ferrites such as Mn-Zn ferrite, Ni-Zn ferrite, Mn-Mg ferrite, Mn ferrite, Cu-Zn ferrite, Cu-Mg-Zn ferrite, and hard ferrite that is a permanent magnet material. It is done. An example of pure iron is carbo iron. As materials for soft magnetic powder, these magnetic materials can be used alone or in combination.

The soft magnetic powder may be, for example, a flat soft magnetic powder such as a plate shape including a disk shape, a spheroid shape obtained by rotating an ellipse around a short axis, or a needle shape, a fiber shape, a sphere shape, for example. Non-flat soft magnetic powders such as a shape, a polyhedron shape and a lump shape may be used. Preferably, a flat soft magnetic powder having a high magnetic permeability is used as the soft magnetic powder. As the soft magnetic powder, it is possible to use only one type of powder, or a combination of multiple types of powder, but when combining multiple types of powder, At least one type is preferably flat.

The particle size of the soft magnetic powder is 1 nm to 1000 μm, preferably 10 nm to 300 μm. In the case of flat soft magnetic powder, the aspect ratio is 2 or more and 500 or less, preferably 10 or more and 100 or less. Especially use nano-sized magnetic fine powder Therefore, in the shield layer in the UHF band and SHF band, the value of the real part, of the complex relative permeability is increased to, for example, 10 or more, and the value of the imaginary part of the complex relative permeability, is decreased to, for example, 5 or less. can do.

In addition, in order to increase the insulating property of the soft magnetic powder, an organic or inorganic coating layer may be formed by coating treatment such as plating, welding, or electrodeposition. The soft magnetic powder may have an acid coating on the surface in order to improve the corrosion resistance. The surface of the magnetic powder is preferably subjected to a surface treatment. As the surface treatment agent, a general treatment method using a coupling agent or a surfactant can be used. Further, all means for improving the wettability between the magnetic powder and the binder, such as a resin coating and a dispersing agent, can be used.

The shield layer 13 is made of a material having or including at least one of a soft magnetic metal, a soft magnetic metal oxide, a magnetic metal, and a magnetic acid metal as a magnetic material. As described above, the shield layer 13 is made of at least one of a soft magnetic metal, a soft magnetic metal oxide, a magnetic metal, and a magnetic acid / metal, and at least one of powder and fine particles. Further, it may be configured to be dispersed, or may be formed into a film including a thin film by at least one of soft magnetic metal, soft magnetic metal oxide, magnetic metal, and magnetic metal oxide.

For the shield layer 13 configured to disperse the magnetic material in the binder 20, the group force of ferrite, iron alloy, and iron particles is also selected as the magnetic material with respect to 100 parts by weight of the organic polymer as the binder 1 1 or It is formed from a material containing a plurality of materials at a blending amount of 1 to 1500 parts by weight. The blending amount of the magnetic material with respect to 100 parts by weight of the organic polymer is preferably 10 parts by weight or more and 1000 parts by weight or less. When the blending amount of the magnetic material with respect to 100 parts by weight of the organic polymer is less than 1 part by weight, sufficient magnetic permeability cannot be obtained, and when it exceeds 1500 parts by weight, the workability is inferior and the sheet body 10 cannot be produced. Or manufacturing becomes difficult.

When the configuration of the shield layer 13 is the same, the real part 'and the imaginary part μ' of the complex relative permeability vary depending on the frequency of the target electromagnetic wave, and tend to decrease as the frequency of the target electromagnetic wave increases. In this embodiment, the object to be blocked is Electromagnetic waves to be transmitted include electromagnetic waves with frequencies in the high MHz band and 2.4 GHz band. The real part 'and the imaginary part' of the complex relative permeability tend to decrease as the frequency of the target electromagnetic wave increases. Therefore, including the electromagnetic wave in the high MHz band and 2.4 GHz band. For example, the real part μ and imaginary part μ "of the complex relative permeability compared to the structure aiming to cut off low frequency electromagnetic waves of 1 to 10 MHz, for example. However, the real part μ becomes particularly small.

In order to increase the real part of the complex relative permeability in the shield layer 13, it is necessary to increase the amount of the magnetic material force portion in the shield layer 13. In order to reduce the imaginary part of the complex relative permeability, it is only necessary to reduce the portion of the magnetic field line 25 that also has a nonmagnetic material force. In simple terms, the amount of the magnetic powder 21 in the shield layer 13 is increased. If this is done, the amount of the magnetic material 21 can be increased and the nonmagnetic material force in the path of the magnetic force lines can be reduced. If they come into contact with each other, the shield layer 13 becomes conductive, and a current is generated in the shield layer 13, causing a loss due to resistance and absorbing the electromagnetic energy. It is not possible to increase the amount of.

In the present embodiment, by mixing the magnetic fine particles 22 together with the magnetic powder 21, the magnetic powders 21 are prevented from coming into contact with each other, and the magnetic fine particles 22 are interposed between the magnetic powders 21, thereby providing magnetism. In addition to increasing the amount of the material portion having the non-magnetic material force in the path 25 of the magnetic field lines, it is possible to reduce the portion. Therefore, the complex relative permeability as described above can be obtained for electromagnetic waves in the high frequency band and 2.4 GHz band. For example, the real part ju ′ of the complex relative permeability with respect to the electromagnetic wave of 950 MHz of the shield layer 13 is 19.16, the permeability loss term tan δ μ is 0.58, and the real part ε ′ of the complex relative permittivity is 165. 8 and the dielectric loss term tan δ ε is 0.15. The shield layer 13 has a surface resistivity (IS K6911) of 10 ⁶ Ω / mouth.

In the high frequency range including the high MHz band and 2.4 GHz band, it is difficult to obtain a high value with a large decrease in the real part of the complex relative permeability, even for magnetic metals. In the GHz band, which is 1000 MHz or higher, the magnetic powder 2 is added to the binder 20 rather than the magnetic metal sheet. The direction force of the sheet body 10 including the shield layer 13 in which 1 is dispersed. Both the real part μ and the imaginary part μ ″ of the complex relative permeability may be high and values.

At a low frequency of about 1 MHz to 10 MHz, the real part of the complex relative permeability of the sheet 10 in which the magnetic powder 21 is dispersed in the binder 20 is, of course, the real number of the complex relative permeability of the sheet of magnetic metal alone. Each part is smaller than '. Comparing the decrease rate of the real part 'of the complex relative permeability due to the frequency increase, the decrease rate of the sheet 10 in which the magnetic powder 21 is dispersed in the binder 20 is smaller than the decrease rate of the sheet of magnetic metal alone. . Therefore, in a high frequency range of 300 MHz or higher, particularly in the high MHz band and GHz band (1 GHz or higher and less than ITHz), the inversion phenomenon may occur, and the complex of the sheet 10 in which the magnetic powder 21 is dispersed in the binder 20. The real part, of the relative permeability may be larger than the real part 'of the complex relative permeability of the sheet of the magnetic metal alone. This phenomenon is caused by the magnetic powder 21 and 22 being dispersed apart from each other, resulting in magnetic loss due to the intervening material. Therefore, in the shield layer 13 of the sheet 10, the magnetic resonance frequency is higher on the higher frequency side. Therefore, this is due to the fact that the side force of the MH z band (1 MHz or more and less than 1 GHz) is also shifted to the GHz band side. Furthermore, as indicated by Snoek's limit law, there is a decrease due to the frequency increase of the real part μ, of the complex relative permeability, and the complex relative permeability is linked to the decrease rate of the real part 'of the complex relative permeability with respect to the frequency increase. The imaginary part of the complex metal permeability is higher than 300 MHz, especially in the high frequency range including the high MHz band and the GHz band. Both are large or have a characteristic that the real part μ ′ of the complex relative permeability is small and the imaginary part of the complex permeability is large. In the high frequency range including 300 MHz or higher, particularly including the high MHz band and the GHz band. It is difficult to obtain the characteristics that the real part of the complex relative permeability; z ′ is large and the imaginary part μ ″ of the complex relative permeability is small. The magnetic material has a tendency that as the real part 'of the complex relative permeability in the low frequency region is larger, the reduction rate of the real part' of the complex relative permeability due to the frequency increase is larger. By dispersing the powder (magnetic powder) 21 of the magnetic material having such a tendency in the binder 20, the reduction rate of the real part 'of the complex relative permeability due to the frequency increase is suppressed, and the insulation between the magnetic powders 21 is suppressed. Sex can be secured. Furthermore, in a configuration in which the magnetic powder 21 is simply dispersed in the binder 20, the influence of the binder 20 existing between the magnetic powders 21 causes 300MHz or more, In particular, there is a limit to increasing the real part μ of the complex relative permeability at high frequencies including the high MHz and GHz bands. Therefore, it is necessary to construct a path with a higher real part of the complex relative permeability called a magnetic field path at a micro level so that the magnetic field lines can easily pass through the shield layer 13 of the sheet body 10. In order to form this magnetic field path, magnetic fine particles 22 are mixed. Of course, the formation of the magnetic field path does not result in the shield layer 13 having a conductive configuration! It is necessary to ensure high electrical insulation between the magnetic powders 21. This electrical insulation can be ensured, for example, by adopting a configuration in which the magnetic fine particles 22 are nonconductive at least on the entire outer surface. In the present embodiment, ferrite nanoparticles are used as the magnetic fine particles 22. Since these particles are magnetic oxides, they do not exhibit electrical conductivity.

In this way, the resonance frequency at which the imaginary part of the complex relative permeability; ζ "reaches its peak value shifts to the high frequency side, and further increases to 5 GHz and 10 GHz, so that 300 MHz or more, especially in the high MHz band and 2.4 GHz It is possible to realize the shield layer 13 in which the real part of the complex relative permeability at the band is large and the imaginary part “of the complex relative permeability is small”.

In addition, as a shield layer 13 according to another embodiment of the present invention, in order to increase the filling rate of the magnetic material, two types of magnetic particles having different average particle diameter ratios of about 4: 1 are used as described above. The same binder 20 is mixed, and magnetic fine particles and soft magnetic metal fibers are mixed. Furthermore, in order to ensure electrical insulation, electrically insulating fine particles are mixed. The two types of magnetic particles are made of the same material as the magnetic powder 21, and the larger average particle diameter is about 20 m, and the smaller average particle diameter is about 5 m. The magnetic fine particles and soft magnetic metal fibers are made of an iron-based material, and the average particle diameter of the magnetic fine particles and the average fiber diameter of the soft magnetic metal fibers are about 1 μm. The electrically insulating fine particles are made of silicon oxide (SiO 2), and the average

2

The particle size is about 10nm. The fine particles of this size also have a role of controlling the direction and interval when the magnetic powder 21 is dispersed in the shield layer 13.

Furthermore, in order to eliminate the voids in the shield layer 13 as much as possible, the measured specific gravity value of the shield layer 13 is designed and manufactured so as to be close to the theoretical specific gravity value of the compounding power. In the configuration shown in FIG. 2 instead of the configuration shown in FIG. 2, similarly, the resonance frequency at which the imaginary part “of the complex relative permeability becomes the peak value shifts to the high frequency side, and further, 5 GHz and 10 GHz. By increasing the frequency to GHz, the real part of the complex relative permeability of 300 MHz or higher, especially in the high MHz band and 2.4 GHz band, is large, and the imaginary part of the complex relative permeability is small, and the shield layer 1

3 can be realized.

In addition, the basic idea of the material design of the shield layer 13 of the present embodiment is to have a high resistance at the communication frequency and to increase the real part 'of the complex relative permeability at the communication frequency to shield the magnetic field component. By drawing into the layer 13 and aligning and arranging the flat magnetic powder microscopically, magnetic anisotropy is imparted by facilitating the flow of magnetism in any direction, and the imaginary part "of the complex relative permeability is lowered. Thus, the magnetic loss can be suppressed, and the effect of the present invention can be obtained.

In the sheet body 10, for example, a flame retardant or a flame retardant aid is added to at least one of the layers 13 to 16. As a result, flame resistance is imparted to the sheet body 10. For example, electronic devices such as mobile phones may be required to be flame retardant for the polymer material that is used in the interior.

The flame retardant for obtaining such flame retardancy is not particularly limited. For example, phosphorus compound, boron compound, bromine flame retardant, zinc flame retardant, nitrogen flame retardant, water An oxide-based flame retardant, a metal compound-based flame retardant, or the like can be used as appropriate. Examples of phosphorus compounds include phosphate esters and titanium phosphate. Examples of the boron compound include zinc borate. Examples of brominated flame retardants include hexabromobenzene, hexacyclodicyclohexane, decabromobenzyl phenol ether, decabromobenzyl phenol oxide, tetrabromobisphenol, and ammonium bromide. Examples of zinc-based flame retardants include zinc carbonate, zinc oxide, and zinc borate. Examples of the nitrogen-based flame retardant include triazine compound, hindered amine compound, melamine cyanurate, melamine jelly compound, and / or melamine compound. Examples of the hydroxy flame retardant include magnesium hydroxide and hydroxyaluminum. Examples of the metal compound flame retardant include antimony trioxide, molybdenum oxide, manganese oxide, chromium oxide, and iron oxide.

In this example, by adding a binder of 100, a brominated flame retardant of 20, an antimony trioxide of 10, and a phosphate ester of 14 in a weight ratio, UL was added. 94 Flame retardant equivalent to VO can be obtained in the flame retardant test. The sheet body 10 can be suitably used as a material constituting such an article or attached to the article. For example, it can be suitably used by attaching it to an article used in a space where it is desired to prevent combustion and generation of gas accompanying it, such as an aircraft, a ship, and a device in a vehicle. Further, the sheet body 10 has electrical insulation. Specifically, the surface resistivity (JIS K6911) of the sheet body 10 is 10 ² Ω or more because the layers 11 and 12 also have the material force as described above. The surface resistivity of the shield layer 13 is preferably as large as possible. Therefore, the maximum value that can be realized is the upper limit of the surface resistivity. In this way, it has a high surface resistivity and electrical insulation.

Further, the sheet body 10 has heat resistance. Specifically, when the crosslinking agent is added to rubber or resin material, the heat resistance temperature of the sheet body 10 is 150 ° C, and the sheet body 10 is at least at a temperature exceeding 150 ° C. Until then, there is no change in properties.

The sheet body 10 is given thermal conductivity. The environment in which the sheet body 10 is used may be used in the vicinity of a means serving as a heat source, such as a communication means including an IC and a power supply means. Due to the excellent thermal conductivity of the sheet 10, heat generated by the means serving as the heat source can be released, and the temperature of the means serving as the heat source can be suppressed and exposed to high temperatures. It can prevent 'declining'.

At least one surface portion of the sheet body 10 has adhesiveness or adhesiveness. In the present embodiment, the adhesive layer 15 is provided as described above, whereby the surface portion on the other side in the thickness direction has adhesiveness or adhesiveness. The sheet body 10 can be attached to an article by the bonding force due to the adhesiveness or adhesiveness of the adhesive agent layer 15. Therefore, the sheet member 10 can be easily provided between the antenna element 11 and the communication disturbing member 12 or in the vicinity of the antenna element by sticking to the communication disturbing member 12, for example. The sheet body 10 is provided such that one side in the thickness direction is disposed on the antenna element 11 side and the other side in the thickness direction is disposed on the communication disturbing member 12 side. For example, Nitto Denko's No. 5000N power can be used as a sticking agent!

EXAMPLES Hereinafter, although an Example is given and the evaluation method of this invention is demonstrated in detail, this invention is not limited to the following Examples. Example 1 is 100 parts by weight of hydrogenated-tolyl rubber (HNBR, “Zeppol” manufactured by Nippon Zeon Co., Ltd.) as binder 20 and Sendust (Fe—Si—A 1-based alloy) as flat soft magnetic powder (magnetic metal) 21 DT made by Dowa Mining Co., Ltd. 690 parts by weight and 69 parts by weight of ultrafine iron powder (manufactured by JFE Chemical) were added (filled) as magnetic fine particles 22, and surfactants and dispersants were added. Manufactured product name “Permicle D”) was added as a cross-linking agent, and a shield layer 13 was formed by a hot press method, and a sheet body 10 having such a shield layer 13 was produced. In the composition, the polymer fraction is 45.3 vol.% And the magnetic fraction is 46.4 vol.%.

The measured specific gravity value was calculated by calculating the weight Z volume force of the sheet obtained above, and the theoretical specific gravity value was calculated by dividing the total specific gravity X content of each component by the volume. The theoretical specific gravity value in this example was 3.89, and the measured specific gravity value was 3.53.

With respect to the shield layer 13 obtained above, the material constants (the real part 'and the imaginary part' of the complex relative permeability and the real part ε 'and the imaginary part ε' of the complex relative permittivity were measured by the coaxial tube method. Specifically, a ring-shaped sample having the same configuration as that of the shield layer 13 and having an outer diameter of 7 mm and an inner diameter of 3 mm is prepared, and a conductive paint is applied to the contact portion of the sample inside the coaxial tube and dried. The part is connected to an Agilent network analyzer 8720ES via a coaxial cable, and S 11 (reflection attenuation strength) and S21 (transmission attenuation strength) are measured. This is the real part 'and imaginary part of the complex relative permeability. "The real part ε 'of the complex relative permittivity and the imaginary part ε" of the complex relative permittivity are measured in the same manner as the real part' and the imaginary part "of the complex relative permittivity. Real part 'and imaginary part' of relative permeability and complex ratio induction When one or more of the real part ε 'and imaginary part ε "of the electric power are unspecified, it is called a material constant.

FIG. 3 is a graph showing the measurement results of the material constants', μ ε ε ”of Example 1. In FIG. 1, the real part of the complex relative permeability is indicated by“ ♦ ”and“ country ”. The imaginary part "of the complex relative permittivity" is indicated by the mark, the real part ε, of the complex relative permittivity is indicated by the "△" mark, and the imaginary part ε "of the complex relative permittivity is indicated by the" X "mark. As shown in Table 1 and Fig. 3, the real part of the complex relative permeability for electromagnetic waves of 950 MHz is 19.16, the permeability loss term tan δ μ is 0.58, and the complex relative permittivity The real part ε 'is 165.8, the dielectric loss term tan S ε is 0.15, and the surface resistivity (JIS K6911) is 10 ⁶ Ω / mouth. FIG. 4 is a cross-sectional view showing the tag 30 including the sheet body 10 in a simplified manner. FIG. 5 is a perspective view showing the tag 30. The tag 30 is one of electronic information transmission devices that transmit information by wireless communication. For example, the tag 30 is used as a transbonder of an RFID (Radio Frequency ID entification) system used for automatic recognition of solid objects. The tag 30 includes an electric field type antenna element 11, an integrated circuit (hereinafter referred to as “IC”) 17 that is a communication means that is electrically connected to the antenna element 11 and communicates using the antenna element 11, and a sheet body 10. And. The tag 30 may be configured to transmit a signal representing information stored in the IC 17 by the antenna element 11 when the antenna element 11 receives a request signal from the reader. Therefore, the reader can read the information held in the tag 30. The tag 30 is attached to a product, for example, and is used for product management, such as prevention of product theft and grasping inventory status. The antenna device is configured to include the antenna element 11 and the sheet body 10. Although not shown in FIG. 4, a matching circuit may be added. As described above, the antenna element 11 which is an antenna means is a dipole antenna. The antenna element 11 is realized by a pattern conductor formed on the surface portion on one side in the thickness direction of the base material 18 that also has a polyethylene terephthalate (PET) force. The IC 17 is disposed, for example, at the center of the antenna element 11 and is electrically connected. The IC 17 has at least a storage unit and a control unit. Information can be stored in the storage unit, and the control unit can store information in the storage unit or read out storage unit force information. In response to a command represented by the electromagnetic wave signal received by the antenna element 11, the IC 17 stores information in the storage unit or reads information stored in the storage unit and sends a signal representing the information to the antenna element. Give to 11. The base material 18 has a rectangular plate shape, and the antenna element 11 is provided at the center of the base material 18 so as to extend in the longitudinal direction. The thickness dimension of the layers of the antenna element 11 and the IC 17 is 1 nm or more and 500 / zm or less, and the thickness dimension of the layer of the substrate 18 is 0.1 m or more and 2 mm or less. The antenna element 11 may be printed and processed directly on the sheet body 10 so that the base material is not used.

The antenna body 11, the IC 17, and the base material 18 constitute a tag body 33. The tag body 33 is packaged by being mounted on a flexible adhesive tape. A tag 30 is configured by the tag body 33 and the sheet body 10. Figure 4 shows a simplified The sheet body 10 is laminated in a state where the sheet body 10 is adhered to the tag body 33. Although not shown in FIG. 4, a force that uses an adhesive or an adhesive between the tag body 33 (some configurations do not include the base material 18) and the sheet body 10 includes the tag body 33 or the sheet body 10 In some cases, one or both of them may be attached because they are sticky or adhesive. The tag body 33 has a surface portion opposite to the side on which the antenna element 11 and the IC 17 are provided facing the sheet body 10, and a force opposite to the layer such as the conductor layer 14 is coupled to the shield layer 13 of the sheet body 10. Is done. The coupling structure between the sheet body 10 and the tag body 33 is not particularly limited, but may be coupled using a binder including an adhesive and an adhesive. In FIG. 3, a configuration for coupling the sheet body 10 and the tag main body 33 is omitted. The tag 30 has an antenna element 11 and an IC17 layer, a base material 18 layer, a shield layer 13, a binder layer 16, a conductor layer 14 and an adhesive layer 15 in this order from one side to the other side in the thickness direction. Are stacked. The sheet body 10 and the base material 18 are formed in the same rectangular shape. As described above, the tag body 33 may have the orientation shown in FIG. 4 or may be configured upside down on the drawing.

The antenna element 11 can transmit an electromagnetic wave signal in a direction intersecting with the direction in which the antenna element 11 extends, and can receive an electromagnetic wave signal coming from a direction intersecting with the direction in which the antenna element 11 extends. In the present embodiment, an electromagnetic wave signal is transmitted in the direction of transmission / reception direction A on the opposite side of the base material 18 and the sheet body 10 with respect to the antenna element 11, and the electromagnetic wave signal in the direction of transmission / reception A is received. Can do. Transmission / reception direction A indicates the main direction, but there is a case where communication is performed using a wraparound radio wave, and the direction is not limited to that direction.

The tag 30 has information to be stored in advance (hereinafter referred to as “main information” and “!”) And information for instructing to store the main information (hereinafter referred to as “storage command information”) from an information management device that is a reader, for example. When the antenna element 11 receives the electromagnetic wave signal representing the main information and the storage command information, the antenna element 11 provides the IC 17 with the electric signal. The IC tag 17 causes the control unit to store main information in the storage unit based on the storage command information. In addition, an electromagnetic wave signal representing information (hereinafter referred to as “transmission command information” t ヽぅ) that instructs the information management device to transmit information stored in the storage unit (hereinafter referred to as “stored information” t) is an antenna. When received by the element 11, an electrical signal representing the transmission command information is transmitted to the antenna element 11. To IC17. In the IC tag 17, the control unit reads information (stored information) stored in the storage unit based on the transmission command information, and gives an electric signal representing the stored information to the antenna element 11. As a result, an electromagnetic wave signal representing stored information is transmitted from the antenna element 11.

Thus, the tag 30 is an electronic information transmission device that transmits and receives an electromagnetic wave signal by the antenna element 11. The tag 30 may be a battery-driven tag driven by a built-in battery, or may be a batteryless tag that returns an electromagnetic wave signal using the energy of the received electromagnetic wave signal.

Such a tag 30 includes a sheet body 10 so that the tag 30 can be used in the vicinity of the communication blocking member 12. As an example, the sheet body 10 is provided on the side opposite to the transmission / reception direction A with respect to the antenna element 11. The sheet body 10 is used by being attached to the communication hindering member 12 using the adhesive layer 15. In the tag 30, the sheet body 10 is disposed closer to the communication interference member 12 than the antenna element 11, and the sheet body 10 is interposed or disposed between the antenna element 11 and the communication interference member 12 or in the vicinity of the antenna element. It is provided as follows.

FIG. 6 is a cross-sectional view showing an electric field formed in the vicinity of the antenna element 11 in a state where the tag 30 is attached to the communication disturbing member 12. FIG. 7 is a cross-sectional view showing an electric field formed in the vicinity of the antenna element 11 in a state where the antenna element 11 and the IC tag 17 are arranged in the vicinity of the communication disturbing member 12 without the sheet body 10 interposed. For ease of understanding, FIG. 6 omits the configuration of the tag 30 except for the antenna element 11, the IC 17, and the shield layer 13. In free space where the communication interference member 12 does not exist in the vicinity of the antenna element 11, the electric field force generated by the potential difference between both ends 11a and l ib of the antenna element 11 spreads as it is, and a magnetic field is formed by the change in the electric field strength. An electric field is formed by a change in the strength of the magnetic field. The antenna element 11 can transmit an electromagnetic wave by utilizing such a principle that the formation phenomenon of the electric field and the magnetic field is successively repeated. The antenna element 11 can receive an electromagnetic wave having a resonance frequency by a principle opposite to the transmission principle.

As shown in FIG. 7, when the communication disturbing member 12 is present in the vicinity of the antenna element 11, the electric field generated at both ends of the antenna element 11 is affected by the electrical influence received from the communication disturbing member 12. Although it cannot be ignored and depends on the frequency, a short-circuit phenomenon occurs in the frequency range above the MHz band, and as a result, the impedance of the antenna element 11 is lowered.

That is, in a state where a potential difference is generated at both ends 11a and l ib of the antenna element 11, both ends 11a and l ib of the antenna element 11 are charged positively or negatively, respectively. An electric field is formed between both end portions 11a and l ib and both end portions 11a and 12b of antenna element 11 in communication jamming member 12, and both ends 11a and l ib of antenna element 11 are formed. It will be in the state of being charged oppositely. An alternating voltage is applied to the antenna element 11 by the IC, and both end portions 11a and l ib are charged so that positive and negative are alternately switched, and in synchronization therewith, each portion 12a, 12a, 12b will also be charged so that positive or negative will alternate. Hereinafter, in FIG. 6 and FIG. 7, the left end of the antenna element 11 is defined as one end 11a, the right end is defined as the other end l ib, and each of the portions 12a and 12b of the communication disturbing member 12 is The left part is the one part 12a and the right part is the other part 12b.

When observed for a short time, a current 111 is generated from the other end 1 lb of the antenna element 11 to the one end 1 la, and the communication disturbing member 12 is directed from the one part 12a to the other part 12b. Force current 112 is generated. In this way, a reverse current is generated. As described above, since an alternating voltage is applied to the antenna element 11 by the IC, a state in which a current in the direction shown in FIG. 7 is generated and a state in which a current in the direction opposite to that in FIG. 7 is generated alternately occur. To do. When the frequency is increased, the gap between one end 11a of the antenna element 11 and one part 12a of the communication disturbing member 12 and between the other end l ib of the antenna element 11 and the other part 12b of the communication disturbing member 12 are The resulting force 10 is equivalent to a current 10 and is equivalent to a state where the current is generated between the one end 1 la of the antenna element 11 and the one portion 12a of the communication blocking member 12 and the other end l ib of the antenna element 11. It is equivalent to a short circuit between the other part 12b of the communication disturbing member 12. In other words, it becomes short-circuited at a high frequency. This phenomenon of short-circuiting at a high frequency is the same phenomenon as when a high-frequency voltage is applied to the capacitor, it becomes the same state as when it is energized.

When such a high-frequency short circuit occurs, the antenna element 11 and the communication disturbing member 12 As a result, a closed circuit is formed, and the current value increases compared to the case where the communication disturbing member 12 does not exist in the vicinity. That is, the impedance is reduced as compared with the case where there is no communication blocking member 12 in the vicinity of the antenna element 11. If the impedance is Z, the voltage value is V, and the current value is I, the impedance Z is Z = VZl, and since the current value I increases, the force that the impedance Z is reduced is also confirmed. ing. The impedance Z is an impedance of a circuit formed by the antenna element 11 and the communication disturbing member 12, but is also an input impedance of the antenna element 11 constituting the circuit. Therefore, if the communication obstruction member 12 is present in the vicinity of the antenna, the input impedance of the antenna element 11 is lowered. On the other hand, as shown in FIG. 6, the sheet body 10 is connected to the electric field type antenna element 11 and obstructs communication. If it is provided between the member 12 and the both end portions 11a and ib of the antenna element 11, the strength of the electric field formed between the member 12 and the communication disturbing member 12 is reduced. Therefore, the formation of a high-frequency short circuit is weakened, and a decrease in the input impedance of the antenna element 11 is suppressed. The suppression of the decrease in the input impedance is confirmed by the fact that the current value of the current generated in the antenna element 11 is close to the value in the absence of the communication disturbing member 12! /. By using the sheet body 10 in this way, it is possible to suppress a decrease in input impedance.

The present inventor uses the numerical values of the material constants ', μ ε', ε "of Example 1 shown in Table 1 and FIG. 3 to determine that the antenna element 11 that is a dipole antenna is in the vicinity of the metallic communication disturbing member 12. In some cases, the impedance recovery degree of the antenna element 11 was calculated by an electromagnetic field simulator (Sonnet) with the sheet 10 sandwiched between the antenna element 11 and the communication disturbing member 12 or in the vicinity of the antenna element.

The configuration used for the simulation is shown in Figure 4. The conductor layer 14 has a copper (Cu) plate, which is a metal plate, and is provided with a 50 μm-thick adhesive layer 16 and a 500 μm-thick shield layer 13, and the substrate 18 is a 100 μm-thick PET film The antenna element 11 which is an antenna element is arranged in As a result, the input impedance was 126 Ω (the frequency at which reactance was zero at 1 GHz), and the radiation efficiency was 3% (gain 12.6 dB).

The sheet body 10 is provided between the electric field type antenna element 11 and the communication disturbing member 12. Therefore, when the antenna element 11 is disposed in the vicinity of the communication disturbing member, it is possible to suppress a decrease in input impedance of the antenna element due to a member having a portion made of a conductive material. If the sheet member 10 is not used, the electric field type antenna element 11 hardly operates in the vicinity of the communication disturbing member 12, and cannot be used for wireless communication. This is because the input impedance of the electric field type antenna element 11 is significantly reduced. When the input impedance of the electric field type antenna element 11 is reduced, the electric field type antenna element 11 is used to diverge from the impedance of the IC 17 that communicates, and the signal is transferred between the electric field type antenna element 11 and the IC 17. You will not be able to. The sheet body 10 can suppress a decrease in input impedance of the antenna element 11 when the antenna element 11 is disposed in the vicinity of a member having a portion that also has a conductive material force. In order to increase the force induced loss (tan δ ε = ε V ε '), where the dielectric constant and dielectric loss are to be increased because of the electric field antenna, it is necessary to increase the imaginary part ε "of the complex relative permittivity However, if the imaginary part ε "of the complex relative permittivity becomes larger than necessary, the conductivity will increase, contributing to the direction of a short circuit. In the present invention, in addition to the dielectric constant, the control of the magnetic permeability is selected as a means, and the impedance is efficiently recovered. In other words, by using the dielectric constant and the magnetic permeability together and not increasing the conductivity too much, the communication improvement effect can be obtained. Therefore, by using the sheet member 10, wireless communication can be suitably performed even in the vicinity of the communication disturbing member 12 using the electric field type antenna element 11.

Specifically, when the antenna element 11 is a dipole antenna, the force that connects the IC 17 to the center of the dipole antenna. The impedance of the IC 17 is, for example, 40 Ω or 50 Ω. In order to match this impedance, at least the antenna impedance needs to be about 10 Ω.

This is because when a metal is brought close to the antenna element 11, the resistance decreases and the impedance also decreases. As shown in the calculation example, when the sheet body 10 is not used, if there is only a dielectric having a thickness of 0.53 mm between the antenna element 11 and the communication disturbing member 12, the impedance is 0.85 Ω. This number is too small compared to 40 Ω. In the tag 30, the antenna element 11 and the IC 17 are directly attached to simplify the configuration. Impeder on the way There is no circuit for adjusting the resistance. Therefore, the impedance difference is fatal. On the other hand, by providing the sheet member 10, it is possible to suppress a decrease in the input impedance of the antenna element 11.

In order to further suppress the attenuation of electromagnetic energy, attention is focused on the generation of magnetic field components during energy attenuation, and the magnetic field is collected by increasing the real part; z ′ by adjusting the complex relative permeability of the sheet body 10, and The energy of the collected magnetic field is prevented from being converted into thermal energy by reducing “.” When adjusting the complex magnetic permeability of the sheet body 10 in this way, when adjusting the complex relative permittivity of the sheet body 10 In comparison, it is easier to obtain an effect of suppressing the attenuation of electromagnetic energy because the magnetic field becomes stronger as it is closer to the source, so even if it is a thin sheet, it works effectively if the complex relative permeability is adjusted. It is.

Further, by suppressing the loss of electromagnetic energy, the radiation efficiency of the antenna characteristics of the antenna element 11 can be increased. Radiation efficiency 7? = ₁₀ ⁽ Gain—Directional gain can be expressed as ^10. Directivity gain is a gain that does not include loss of metals, etc. Gain (usually, if only Gain is written, click here) Is a true gain that includes loss.The calculation results show that it is necessary to reduce the loss to improve (increase) the radiation efficiency. If the radiation resistance is Rrad and the loss resistance is Rloss, the radiation efficiency is 7? = RradZ (Rrad + Rloss) Since Rrad corresponds to the resistance of the input impedance of the lossless antenna, resistance is set by bringing a metal closer to the antenna element 11. Therefore, the radiation efficiency decreases, and therefore, the radiation efficiency can be increased by suppressing the decrease in the input impedance of the antenna element 11.

Furthermore, since the length of the antenna element 11 is affected by the wavelength shortening effect due to the complex relative permittivity and the complex relative permeability of the sheet member 10, the frequency needs to be readjusted. Considering the effect of this shortening of wavelength, severe manufacturing conditions are required. In order to avoid this, the real part of the complex dielectric constant, which tends to be large, must be set to a very small value.

As the antenna element 11, a dipole antenna can be used. Thus, wireless communication can be performed using a dipole antenna having a simple and small configuration in the vicinity of the communication disturbing member 12. Further, the sheet body 10 is provided with a shield layer 13, and the shield layer 13 has a real part 'of complex relative permeability and an imaginary part of complex relative permeability for electromagnetic waves used for wireless communication. Preferably, the real part μ of the complex relative permeability is 5 or more and the permeability loss term tan δ ≤1, more preferably the real part of the complex relative permeability / ζ ′ is 20 The above is the permeability loss term tan δ μ≤0.5. The shield layer 13 has a real part ε ′ of a complex relative dielectric constant of 20 or more with respect to electromagnetic waves used for wireless communication. Further, the shield layer 13 has an imaginary part ε ″ of a complex relative dielectric constant of 300 or less with respect to electromagnetic waves used for wireless communication. Thereby, the antenna element 11 is arranged in the vicinity of the communication disturbing member 12. Sometimes, it is possible to realize a sheet body that can suppress a decrease in input impedance of the antenna element 11 due to the communication disturbing member 12 and also can suppress a loss of electromagnetic energy due to the communication disturbing member 12.

An example of the radiation efficiency simulation results when the power of the complex relative permeability in the 950 MHz band is 50 and the permeability loss term tan δ μ = 0.1 is omitted from the graph. The input impedance was 13 Ω (at 1 GHz, the frequency with zero reactance), and the radiation efficiency was 8% (gain 5. ldB).

FIG. 8 is a cross-sectional view showing the configuration of the sheet body 10 assumed in the simulation for confirming the effect of the sheet body 10 when a dipole antenna is used as the antenna element 11. In this simulation, the sheet body 10 has only the shield layer 13, and the sheet body 10 (shield layer 13) is provided on the antenna element 11 via a dielectric layer corresponding to the base material 18. The communication disturbing member 12 is directly laminated on the sheet body 10 (shield layer 13) so that the layer 13) is disposed between the antenna element 11 and the communication disturbing member 12 having a metal plate force. The communication state was simulated.

FIG. 9 is a graph showing a simulation result by the configuration of FIG. 8 and showing a relationship between the frequency and the real part (Real) and the imaginary part (Imaginary) of the input impedance of the antenna element 11. The frequency at which the imaginary part of this input impedance becomes zero indicates the resonance frequency (953 MHz in Fig. 9). FIG. 10 is a graph showing the directivity gain, showing the simulation result of the configuration of FIG. FIG. 11 is a graph showing a simulation result by the configuration of FIG. 8 and showing absolute gain. Table 1 shows the material constants for each layer in the configuration of Fig. 8. Each material constant is a value at a frequency of 950 MHz.

[table 1]

In this simulation, the dielectric layer corresponding to the base material 18 has a layer thickness lmm where the real part ε ′ of the complex dielectric constant in the 950 MHz band is 1.1 and the dielectric loss term tan δ ε = 0.01. Assuming a dielectric layer (for example, a foam layer such as styrene foam), the real part ε ′ of the complex relative permittivity in the 950 MHz band is 100 and the permittivity loss term tan δ ε = 0.01, and the complex relative permeability A shield layer 13 is assumed in which the real part of the magnetic permeability is 50, the permeability loss term tan δ μ = 0.01, and the conductivity 1 0 ^_4 [SZm]. A dielectric layer (base material 18) is disposed on the antenna element 11 side, and a shield layer 13 is laminated on the dielectric layer as a sheet 10 on the side opposite to the antenna element 11. As a result of such a simulation, the input impedance (real part) is 30 Ω at 953 MHz where the imaginary part (reactance) of the input impedance is zero, and the directional gain is 6.696 dBi (see Θ ( Theta) = 0), the absolute gain was 0.266dBi (value in the case of Θ (Theta) = 0 in Fig. 11), and the radiation efficiency was 25.33%.

In the conventional technology, the use of a magnetic sheet has not been studied with respect to the metal-related problem of the electric field type antenna element 11, that is, the problem with respect to the communication disturbing member 12. This is because the electric field type antenna element mainly uses the electric field, and thus the dielectric constant that is naturally effective for the electric field has been discussed, and the effect of the magnetic permeability has not been sufficiently noted. That is, the impedance recovery effect of the sheet body 10 having magnetic permeability was not known.

The impedance recovery effect using magnetic permeability (which also uses the dielectric constant) is large, and the input impedance of the antenna element 11 due to being placed in the vicinity of the communication interference member 12 falls to near 0 Ω. The real part of the complex relative permeability of the field 11 is 1 It recovers to several tens of ohms by setting it to 0 or more (high frequency band or 2.4 GHz band). As a result, matching can be achieved with the impedance inherent to the IC connected to the communication means and the antenna element 11, for example, 30 Ω and 50 Ω, and it is possible to operate as a resonance circuit including the antenna element first.

Next, if the value of the imaginary part “of the complex relative permeability of the force shield layer 13, which is a loss of electromagnetic energy, is large, the loss increases, and as a result, the radiation efficiency of the antenna element 11 decreases. Complex relative permeability. If the permeability loss term tan δ μ is less than 1 (in the high MHz band or 2.4 GHz band), the loss is slightly reduced, and the permeability loss term tan δ of the complex relative permeability is less than 0.5 (high (In the MHz band or 2.4 GHz band), the loss of electromagnetic energy is further reduced and the radiation efficiency of the antenna element 11 is improved.

The real part ε, of the complex relative permittivity of the shield layer 13 contributes to the wavelength shortening effect that determines the size of the antenna element together with the real part of the complex relative permeability. By setting the real part ε, of the complex relative permittivity to 20 or more, the size of the antenna element 11 can be reduced to about 1/4.

The imaginary part ε ″ of the complex dielectric constant of the shield layer 13 is set to 300 or less.

[Number 1]

"_ _ 1_ _ _σ

ωε ₀ ρ ωε ₀ where ω is the angular frequency (ω = 2 π ί), ε is the dielectric constant of the vacuum (8.841 X 10 ¹² [FZm], f

0

Is the frequency [Hz]. Although the shield layer of the present invention is not a conductive material but a dielectric material, it is calculated from the above equation that is made of a conductive material. When the frequency is 950 MHz, the conductivity is σ ^ 15.9 SZm (resistivity p O. 06 Ω ηι), and at a frequency of 2.4 GHz, conductivity σ ^ 39.9 SZm (resistivity p O. 02 Ω πι) is obtained. Think of it as having a conductivity below this, and a resistivity above this.

In addition, the shield layer 13 is a material that includes at least one of a soft magnetic metal, a soft magnetic metal oxide, a magnetic metal, and a magnetic metal oxide, or a material containing it. There are no particular restrictions on the method used to develop magnetism, but are these materials used directly? This is realized by the direction of dispersion in the binder. With this configuration, it is possible to form a shield layer that can obtain the above-described characteristics. Therefore, the sheet body 10 that achieves the above-described excellent effect can be realized.

Further, since the sheet body 10 has the conductor layer 14, the conductor layer 14 made of a conductive material is present in the vicinity of the antenna element 11, and in accordance with the frequency of the electromagnetic wave used for the above-described wireless communication, The real part and complex part / z "of the complex relative permeability of the shield layer 13 and the real part ε 'and imaginary part ε" of the complex relative permittivity are adjusted. As a result, suitable characteristics of the shield layer 13 can be realized. Therefore, more suitable wireless communication can be realized in the vicinity of the communication disturbing member 12.

Further, by combining the dipole antenna and the sheet body 10 as the antenna element 11, the antenna element 11 can be reduced in size. Combined with the height of the real part μ ′ of the complex relative permeability and the real part ε ′ of the complex relative permittivity of the sheet body 10, the wavelength shortening effect is added, and the size can be significantly reduced compared with the conventional product. it can. The dipole antenna should be linear and have a total length of λ Ζ2 even if it has curves and bending forces. For example, at 950 MHz, it is about 15.8 cm long, but this sheet body has a wavelength shortening effect, and a linear element of about 3 to 10 cm is possible. Sizes that can fit on labels are also possible. Further downsizing can be achieved, and a wide range of objects can be pasted.

In the conventional product, the antenna that operates in the vicinity of the communication interference member 12 is a patch antenna. However, the size of the patch antenna needs to be λ Ζ2 on one side. For example, at 950 MHz, the maximum size is about 15.8 cm square, and it is too large for a tag. In general, the distance between the notch and the ground conductor also needs to be λλ16 to λΖ64, and it cannot be used for applications that require small size and flexibility.

FIG. 12 is a perspective view schematically showing a tag 30 according to another embodiment of the present invention. The tag 30 shown in FIG. 12 has a configuration similar to that of the tag 30 described in FIGS. 1 to 11, and the corresponding components are denoted by the same reference numerals, and only different points will be described. Although the tag 30 described in FIGS. 1 to 11 uses a dipole antenna as the antenna element 11, the tag 30 shown in FIG. 12 uses a monopole antenna as the antenna element 11. Daipo In the single antenna, the IC 17 is provided in the center of the antenna element 11, that is, between the two element pieces constituting the antenna element 11. However, in the monopole antenna, one of the two element pieces is grounded. It is a configuration that can be replaced by the plate 100. The tag 30 configured using such a monopole antenna can obtain the same effects as the tag 30 configured using the dipole antenna as described above. The effect of the sheet body 10 can be obtained in the same manner. Furthermore, a smaller size can be achieved than when a dipole antenna is used. As described above, by using the sheet body 10, the tag 30 using the antenna element 11 is provided in the vicinity of the communication disturbing member 12, such as by sticking it to the communication disturbing member 12, thereby realizing preferable transmission and reception of electromagnetic wave signals. The tag 30 can be used in a ready state. Therefore, for example, the tag 30 can be attached to a beverage 40 containing a beverage in a metal container that is a communication blocking member 12 as shown in FIG. . In addition, the tag 30 includes a large number of communication blocking members 12 such as a board as shown in FIG. 14 and is built in an electronic device 41 such as a mobile phone device, for example, for product management or user authentication and antitheft. It can be used for such purposes. In this way, the tag 30 can be secured for a wide range of uses, highly convenient, and the tag 30 can be realized. Further, since the sheet body 10 has flexibility as described above, it can be freely deformed. As a result, it can be used in a wide range of applications with less restrictions on the installation location. For example, when it is used by being attached to an article, it can be provided following the shape of the article. For example, as shown in FIG. 13, even when the communication blocking member 12 is an article having a cylindrical outer surface, for example, a beverage container, it is possible to attach it following the shape of the surface. is there. Accordingly, it is possible to reduce the restriction on the mounting place of the sheet body 10 and facilitate the mounting work. When used as the tag 30, the material of the other configuration can be appropriately selected so that the tag 30 has a flexible structure as a whole, so that the tag 30 can be attached following the cylindrical surface. become able to.

Further, since the sheet body 10 is provided with adhesiveness on at least one surface portion, when the sheet body 10 is attached to an article, it can be attached to the article using the adhesiveness. As a result, the sheet member 10 can be easily attached to the article. Therefore, the work for using the sheet body 10 and the electronic information transmission device including the sheet body 10 can be facilitated. wear.

Further, the sheet body 10 is flame retardant. An electronic information transmission apparatus that performs radio communication using the antenna element 11 including the tag 30 may be required to be flame retardant. The sheet body 10 can be suitably used for applications that require such flame retardancy.

In addition, the environment in which the sheet is used may be used in the vicinity of a means serving as a heat source, such as a communication means including the IC 17 and a power supply means. Due to the excellent thermal conductivity of the sheet body 10, the heat generated by the heat source means can be released, and the temperature rise of the heat source means is suppressed and the performance deteriorates due to exposure to high temperatures. Can be prevented.

Further, the sheet body 10 has heat resistance and electrical insulation. With regard to heat resistance, it may be used at 120 ° C and 130 ° C, especially for automotive applications, and it must be able to be used without degrading performance at that temperature. Heat resistance can be achieved by adding a cross-linking material and cross-linking the binder. Any cross-linking means can be used, but it is of course possible to achieve heat resistance at a higher temperature (for example, 200 ° C.) by appropriately combining the type of the binder and the cross-linking material. Further, by covering the soft magnetic metal powder with an organic and inorganic insulating material as a binder, the electrical insulation of the sheet body 10 can be improved without direct contact with the soft magnetic metal dispersed in the sheet. it can. If electricity is conducted, an eddy current is generated in itself and the magnetic energy is attenuated. Furthermore, since the circuit and the measuring housing (ground) are arranged in close proximity, if the sheet body 10 has conductivity, it will be conducted through it, which hinders operation. In order to prevent these, the sheet body 10 achieves a surface resistivity of 10 ² Ω / mouth or more.

FIG. 15 is a plan view schematically showing a tag 30 according to still another embodiment of the present invention. In this case, the antenna element 11 also has a substantially annular loop antenna force, and the IC 17 is connected thereto. FIG. 16 is a cross-sectional view showing the tag 30 of FIG. The tag 30 shown in FIGS. 15 and 16 has a configuration similar to that of the tag 30 described in FIGS. 1 to 14, and the same reference numerals are given to the corresponding configurations, and only different points will be described. In the tag 30 shown in FIGS. 15 and 16, a loop antenna is used as the antenna element 11 and is laminated on the base material 18. Ma 15 and FIG. 16, the sheet body 10 has only the shield layer 13, and the antenna element 11 is provided with the sheet body 10 (shield layer 13) via the base material 18.

15 and 16 show a state in which two tags 30 are arranged in a direction perpendicular to the thickness direction while being in contact with each other. The two tags 30 shown in FIG. 15 have the same structure. For the purpose of facilitating understanding in the following description, FIG. 15 shows the antenna element 11 and IC 17 of the left tag 30 with the subscript “a '', And the antenna element 11 and IC17 of the tag 30 on the right side are indicated with a subscript `` b ''. If identification is required in the text, it is identified using a subscript. If unnecessary, explain without using a subscript.

As shown in FIG. 15 and FIG. 16, the state in which the plurality of tags 30 are arranged close to each other is, for example, that a plurality of articles are provided in a dense state, and one tag 30 is attached to each of these articles. The state of the case. The article in this case is, for example, a test tube in which a sample is stored, and is stored in each region of a test tube stand having regions partitioned in a matrix. Each tag 30 is attached to each test tube or test tube lid.

Thus, when a plurality of tags 30 are provided in a dense state, the antenna elements 11 of the other tags 30 for one tag 30 become communication obstructing members, but the sheet body 10 is attached to each tag 30. By providing the sheet body 10 in the vicinity of the antenna element 11, it is possible to prevent a communication failure from occurring in each tag 30. In this way, the sheet body 10 does not have to be provided between the antenna element 11 and the communication disturbing member, here the other antenna element 11, but if it is provided in the vicinity of the antenna element 11, the communication environment of the antenna element 11 can be reduced. Can be improved.

FIG. 17 is a graph showing a simulation result when two tags 30 are placed close to each other as shown in FIG. 15 and FIG. FIG. 18 is a graph showing simulation results when the tag 30 shown in FIG. 15 and FIG. 16 is provided with a sheet member 10 for V! / ヽ, and two tags are similarly placed close to each other. It is. Fig. 17 is a graph showing the relationship between frequency and S-parameter values. The unit of the S parameter value is dB, and the magnitude of the value is compared relatively. Here, “S11” represents the ratio of the reflected power, and “S21” represents the power propagated between the antenna elements 11 (between the ICs 17). Specifically, “S11” has two tags 30 as shown in FIG. When arranged side by side, for example, out of the power supplied to IC17a (or IC17b) of the left (or right) tag 30 on the left (or right) tag 30 IC17a (or IC17b), Represents the percentage of reflected power, and “S21” is the power supplied from the left (or right) tag 30 IC17a (or IC17b), the right (or left) tag 30 IC17b (or IC17a ) Represents the percentage of power transmitted to). Such a state where electric power is transmitted from one IC 17 to the other IC 17 is referred to as coupling in the present invention. In the case of FIG. 15, since the two tags 30 have the same configuration, Sll, S21 when power is supplied from the IC17a of the left tag 30, and Sl1, when power is supplied from the IC17b of the right tag 30, S21 is the same value. In addition, “single coil S ll” represents a value corresponding to “S 11” when the tag 30 as shown in FIG. 15 exists alone in free space.

Table 2 shows the material constants of each layer set in the simulation. Each material constant is a value at a frequency of 2.4 GHz.

[Table 2]

In this simulation, the coupling characteristics between the antenna elements 11 of two loop antennas existing in the vicinity are evaluated using the sheet 10 of the present invention. In the simulation, the shield layer 13 was made by mixing chlorinated polyethylene 100 (part) with carbon iron 530 (part) and kneading it into a sheet. This shield layer 13 has a material constant measured by the coaxial tube method of 2.4. The real part ε 'of the complex relative permittivity is 12.31 at 2.4 GHz, and the permittivity loss term tan S ε = 0.07. The real part of the permeability was 3.0 and the permeability loss term ta η δ = 0.43. This material constant was used in the simulation.

As shown in FIG. 18, in the absence of the sheet body 10, when the two antenna elements 11 are placed close to each other, the parabolas of S11 and S21 have a bimodal shape and have peaks before and after the original communication frequency. Thus, the communication characteristics at the communication frequency are deteriorated. It is an example of communication electromagnetic energy loss. This is due to the coupling between the antenna elements 11. Against this As shown in FIG. 17, when the sheet bodies 10 are laminated, the bimodality disappears and the communication characteristics are improved. This mechanism may be due to changes in the radiation pattern of the electromagnetic wave by the force sheet body 10, which is a guess, changes in the antenna operation by shortening the wavelength by the shield layer, and the influence of the loss component of the shield layer. In any case, it is clear that the communication environment is improved by the sheet 10.

The two antenna elements 11 (tags 30) present in the vicinity are modeled after the reading of the dense tag 30 (transbonder) as described above, and each antenna element 11 serves as a communication blocking member. In particular, there are concerns about the effects of binding. It has been found that by laminating the sheet body 10 of the present invention on the antenna element 11, the coupling between the antenna elements 11 can be relaxed. This example is an example in which the sheet body 10 is not disposed between the antenna element 11 and the communication disturbing member but in the vicinity of the antenna element 11.

Figures 15 to 18 show an example of the ability to arrange two tags 30. Even if electronic information transmission devices such as card-type transponders are stacked, the communication environment is the same as described above. Is improved.

The above-described embodiment is merely an example of the present invention, and the configuration can be changed. For example, the laminated structure may be changed. Specifically, another adhesive layer having the same configuration as the adhesive layer 15 may be provided on the side opposite to the conductor layer 14 and the like with respect to the shield layer 13. When such a sheet body 10 is used for the tag 30, the sheet body 10 is attached to the tag body 33 on which the antenna element 11 and the IC 17 are mounted, and is separately bonded when the tag 30 is configured. Even if no adhesive is used, it can be applied using another adhesive layer, which makes the work easier. Thus, the installation and installation work of the sheet body 10 can be facilitated such that the sheet body 10 can be easily incorporated into the electronic information transmission device. Further, the adhesive layer 15 may be used for attaching the sheet body 10 to the tag body 33 when the adhesive layer 15 is incorporated into the tag 30. In this case, if the other adhesive layer is provided, the other adhesive layer may be used to adhere to the article, or another adhesive layer. If there is no adhesive, it may be attached to the article using an adhesive or an adhesive. Also, the adhesive layer 15 and the other adhesive layer form these layers that are not essential components. Instead, the pressure-sensitive adhesive or the adhesive may be added to a layer such as the shield layer 13 to give the surface of the sheet body 10 pressure-sensitive adhesiveness or adhesiveness.

Further, the means for imparting flame retardancy may be another configuration instead of the configuration in which the flame retardant is added. Further, the minimum required performance of the sheet body 10 is the performance of blocking the magnetic field, and the other performance may be a configuration that is not an essential requirement. Further, the use of the sheet body 10 is not limited to the tag 30, but may be a trans bonder other than the tag 30! / Thanks to an electronic information transmission device other than the trans bonder! It can be configured as an antenna device using the antenna element 11 and the sheet body 10. Examples of electronic information transmission devices other than tag 30 include antennas, readers, reader Z writers, mobile phone devices, PDAs, and personal computers that form RFID systems together with tag 30. Other anti-theft devices, robots It can be any antenna functional component that uses wireless communication technology such as remote control of the remote control, in-vehicle ECU, and other radio waves. As described above, the frequency is not limited to the radio wave range. The use of the sheet 10 is not limited to the electronic information transmission device, and can be widely used in applications where there is a requirement to block at least the magnetic field. Further, the tag 30 may be an article having the communication blocking member 12 other than the aforementioned article.

When a conductive conductor layer is laminated on the sheet body 10, it can function as an antenna even when wireless communication is performed in the vicinity of a member having a portion made of any conductive material by adjusting the resonance frequency of the antenna. become. A known means can be used to adjust the resonance frequency of the antenna.

It may be a configuration change other than these change examples.

The present invention can be implemented in various other forms without departing from the spirit or main characteristic power thereof. Therefore, the above-described embodiment is merely an example in all respects, and the scope of the present invention is shown in the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the scope of claims are within the scope of the present invention.

Industrial applicability

According to the present invention, the antenna element is made of a conductive material by providing a sheet body. When the antenna is disposed in the vicinity of the member having the portion, it is possible to suppress a decrease in the input impedance of the antenna element. Therefore, by using the sheet member, wireless communication can be suitably performed even in the vicinity of a member having a portion made of a conductive material using an electric field type antenna element.

Further, according to the present invention, by providing the sheet body, it is possible to suppress the loss of electromagnetic energy when the antenna element is disposed in the vicinity of the member having a portion made of a conductive material. Therefore, by using the sheet body, radio communication can be suitably performed in the vicinity of a member having a portion made of a conductive material using an electric field type antenna element.

Further, according to the present invention, by using a sheet body, at least one of a dipole antenna, a monopole antenna, a loop antenna, or an antenna loaded with a reactance structure portion on a simple and small configuration is made of a conductive material. It can be used for wireless communication near a member having a part.

According to the present invention, wireless communication can be suitably performed using an electromagnetic wave having a frequency of 300 MHz to 300 GHz in the vicinity of a member having a portion made of a conductive material. Since electromagnetic waves of such frequency are used, a relatively long wireless communication distance can be realized with a small antenna.

Further, according to the present invention, since the frequency force of electromagnetic waves used for wireless communication is a frequency included in the range of 860 MHz to 1 GHz, it can be applied to communication between relatively distant devices, and is a small electric field type. It is possible to enable communication using the antenna. In addition, according to the present invention, the frequency of electromagnetic waves used for wireless communication is a frequency included in the 2.4 GHz band, so that it can be applied to communication between relatively distant devices, and is an electric field type. It is possible to enable communication using a small antenna.

Further, according to the present invention, even when the electric field type antenna is used, the impedance reduction can be controlled by using the shield layer that is a magnetic material, and it is used in the vicinity of a member having a portion made of a conductive material. Wireless communication is possible.

Further, according to the present invention, since the real part / z ′ of the complex relative permeability of the shield layer is equal to or more than the imaginary part μ ″ of the complex relative permeability, the input impedance of the antenna element is reduced and the electric power is reduced. The sheet | seat body which can suppress the loss of magnetic energy is realizable.

Further, according to the present invention, since the real part / z ′ of the complex relative permeability of the shield layer is 5 or more and the permeability loss term tan δ μforce ^ or less, the input impedance of the antenna element is reduced, and A sheet body capable of suppressing loss of electromagnetic energy can be realized.

Further, according to the present invention, since the real part / ζ ′ of the complex relative permeability of the shield layer is 20 or more and the permeability loss term tan δ μ is 0.5 or less, the input impedance of the antenna element is reduced. It is possible to realize a sheet body that can suppress the decrease and the loss of electromagnetic energy.

Further, according to the present invention, since the real part ε ′ of the complex relative permittivity of the shield layer is 20 or more, a sheet body that can suppress a reduction in input impedance of the antenna element and a loss of electromagnetic energy is realized. can do.

In addition, according to the present invention, since the imaginary part ε ″ of the complex relative permittivity of the shield layer is 300 or less, a sheet body that can reduce the input impedance of the antenna element and suppress the loss of electromagnetic energy is realized. can do.

According to the present invention, the real part 'and the imaginary part' of the complex relative permeability of the shield layer or the real part ε 'of the complex relative permittivity is adjusted in the state where the conductor layer exists in the vicinity of the antenna element. Therefore, it is possible to realize a preferable characteristic of the shield layer, and it is possible to realize a more preferable wireless communication in the vicinity of a member having a portion made of a conductive material.

Further, according to the present invention, the material is a material that includes at least one of a soft magnetic metal, a soft magnetic metal oxide, a magnetic metal, and a magnetic metal oxide, or a material that includes the material. A shield layer capable of obtaining characteristics can be formed. Therefore, it is possible to realize a sheet body that achieves the excellent effects described above.

Further, according to the present invention, with respect to 100 parts by weight of the organic polymer, one or more materials selected from the group consisting of ferrite, iron alloy, and iron particles as a magnetic material are 1 part by weight or more and 1500 parts by weight or less. A blending amount of the shield layer is formed. Therefore, it is possible to realize a sheet body that achieves the above-described excellent effects. Further, according to the present invention, the flame retardancy of the sheet body can be obtained, and it can be suitably used for applications requiring flame retardancy.

Further, according to the present invention, when used in the vicinity of the means serving as the heat source, the heat generated by the means serving as the heat source can be released, and the temperature rise of the means serving as the heat source can be suppressed and the temperature can be increased. Performance degradation due to exposure can be prevented.

Further, according to the present invention, at least one surface portion has adhesiveness or adhesiveness, and therefore can be attached to another article. Thus, the sheet body can be easily used.

Further, according to the present invention, it is possible to realize an antenna device that is provided in the vicinity of a member provided with a sheet body and having a portion made of a conductive material, and that can be suitably used for wireless communication.

Further, according to the present invention, it is possible to realize an electronic information transmission device capable of suitably performing wireless communication even when provided in the vicinity of a member having a portion made of a conductive material cover.

In addition, according to the present invention, even if a transbonder is attached to an article that is in a dense state, the influence of the electromagnetic coupling with other transbonders and other transbonders is suppressed, and the reading rate by the reader is improved. can do.

Claims

The scope of the claims

[1] When wireless communication is performed in the vicinity of a member having a portion made of a conductive material using an electric field type antenna element, it is provided between the antenna element and a member having a portion made of a conductive material or in the vicinity of the antenna element. And a structure that suppresses a decrease in input impedance of the antenna element due to a member having a portion made of a conductive material.

[2] When performing wireless communication in the vicinity of a member having a portion made of a conductive material using an electric field type antenna element, it is provided between the antenna element and a member having a portion made of a conductive material or in the vicinity of the antenna element. And a structure that suppresses electromagnetic energy loss caused by a member having a portion made of a conductive material.

[3] The sheet body according to claim 1 or 2, wherein the antenna element includes at least one of a dipole antenna, a monopole antenna, a loop antenna, and an antenna loaded with a reactance structure portion.

[4] The sheet body according to any one of claims 1 to 3, wherein the frequency of the electromagnetic wave used for wireless communication is included in a range of 300 MHz to 300 GHz.

5. The sheet body according to claim 4, wherein the frequency of the electromagnetic wave used for wireless communication is included in a range of 860 MHz to 1 GHz.

[6] The sheet body according to [4], wherein the frequency of electromagnetic waves used for wireless communication is included in the 2.4 GHz band.

[7] The sheet body according to any one of [1] to [6], further comprising a shield layer that is a magnetic body.

[8] The method according to claim 1, further comprising: a shield layer in which a real part / z ′ of the complex relative permeability is not less than an imaginary part μ ″ of the complex relative permeability at the frequency of the electromagnetic wave used for wireless communication. The sheet body according to any one of? 7.

[9] A shield layer having a real part / ζ ′ of a complex relative permeability of 5 or more and a permeability loss term tan δ 1 or less at a frequency of an electromagnetic wave used for wireless communication is provided. Item 10. The sheet body according to any one of items 1 to 8.

[10] The real part / z 'of the complex relative permeability is 20 or less at the frequency of the electromagnetic wave used for wireless communication. The sheet body according to any one of claims 1 to 8, further comprising a shielding layer having a magnetic permeability loss term tan δ of 0.5 or less.

[11] The method according to any one of claims 1 to 10, further comprising a shield layer having a real part ε 'of a complex relative permittivity of 20 or more at a frequency of an electromagnetic wave used for wireless communication. Sheet body.

12. A shield layer having an imaginary part ε ″ of a complex relative dielectric constant of 300 or less at a frequency of an electromagnetic wave used for wireless communication is provided. The sheet body described in 1.

[13] The sheet body according to any one of [1] to [12], further comprising a conductive layer having conductivity.

[14] The shield layer is characterized in that as a magnetic material, a material composed of at least one of soft magnetic metal, soft magnetic metal oxide, magnetic metal and magnetic metal oxide, or a material force containing the material is also provided. The sheet body according to any one of claims 1 to 13.

[15] The shield layer is composed of one or more materials selected from the group strength of ferrite, iron alloy and iron particles as a magnetic material with respect to 100 parts by weight of the organic polymer. The sheet body according to any one of claims 1 to 14, characterized in that the material strength included in the blending amount is also included.

[16] The sheet according to any one of claims 1 to 15, wherein flame retardancy is imparted.

[17] The sheet body according to any one of [1] to [16], wherein thermal conductivity is imparted.

[18] The at least one surface portion is sticky or adhesive.

The sheet body according to any one of 1 to 17.

[19] An electric field antenna element having a resonance frequency matched to a frequency used for wireless communication;

An antenna device comprising the sheet body according to any one of claims 1 to 18.

20. An electronic information transmission device comprising the antenna device according to claim 19. 21. The electronic information transmission apparatus according to claim 20, wherein the electronic information transmission apparatus is used as a transbonder attached to an article in a dense state.