202 results about "Electromagnetic wave absorber" patented technology

An electromagnetic wave absorber comprising (a) soft ferrite having its surface treated with a silane compound having no functional group, (c) magnetite and (d) silicone, or comprising (a) soft ferrite having its surface treated with a silane compound having no functional group, (b) flat, soft magnetic metal powder, (c) magnetite and (d) silicone, which electromagnetic wave absorber excels in electromagnetic wave absorption, heat conduction and flame resistance, exhibiting less temperature dependence, and which electromagnetic wave absorber is soft, excelling in adhesion strength and further excelling in high resistance high insulation properties and in energy conversion efficiency being stable in MHz to 10 GHz broadband frequency. There is further provided a laminated electromagnetic wave absorber comprising the above electromagnetic wave absorber overlaid with a reflection layer of conductor, which laminated electromagnetic wave absorber can be closely stuck onto an unwanted electromagnetic wave emission source such as a high-speed operating device, having such an adhesive strength that even when stuck to a horizontal glassy-surface ceiling face of resin-made cage, would not fall.

Provided is a wideband electromagnetic wave (EMW) absorber including a magnetic composite having a structure in which magnetic particles are dispersed in a polymer resin, and a plurality of conductive lines arranged in the magnetic composite, and a method of manufacturing the same. The wideband EMW absorber can be used for a device configured to emit EMWs and effectively absorb wideband EMWs.

A conductive pattern basically has a substantially polygonal outline shape which is a polygon and can have a high peak value of the electromagnetic wave absorption amount as compared to a case when the conductive pattern has a circular outline shape. Thus, the conductive pattern is basically a polygon and at least one corner portion is shaped in curve. This reduces or even minimizes the shift of the frequency at which the absorption amount becomes a peak value by the polarization direction of the electromagnetic wave. Accordingly, in at least one embodiment, it is possible to realize an electromagnetic absorber having an excellent electromagnetic wave absorption characteristic exhibiting a high peak value of the absorption amount of the electromagnetic wave and a small shift of frequency at which the absorption amount becomes a peak value by the polarization direction of the electromagnetic wave.

When local heating by use of laser sealing or the like is applied, the bonding strength between glass substrates and a sealing layer is improved to provide an electronic device having increased reliability. An electronic device includes a first glass substrate, a second glass substrate, and a sealing layer to seal an electronic element portion disposed between these glass substrates. The sealing layer is a layer obtained by locally heating a sealing material by an electromagnetic wave, such as laser light or infrared light, to melt-bond the sealing material, the sealing material containing sealing glass, a low-expansion filler and an electromagnetic wave absorber. In the first and second glass substrates, each reacted layer is produced to have a maximum depth of at least 30 nm from an interface with the sealing layer.

An electromagnetic wave absorber includes a ground layer made of a metal conductor, a dielectric layer formed on the ground layer, and a unit cell pattern made of a resistive material, and formed on the dielectric layer. The unit cell pattern includes a fundamental patch having a regular square shape, in which a rectangular recess is formed on the center of each of the respective sides, the fundamental patch being located at the center of each of the unit cell pattern, and half cross dipole patches, which are respectively disposed at the four sides of the fundamental patch at a regular angle so as to be engaged with the recesses formed on the respective sides of the fundamental patch at a regular interval.

The present invention provides a composite film having a linearly-scratched, thin metal film and a plastic film, which has good absorbability to electromagnetic waves in various frequencies, as well as reduced anisotropy in electromagnetic wave absorbability, suitable for electromagnetic wave absorbers, and its production apparatus. The composite film having a linearly-scratched, thin metal film and a plastic film according to the present invention comprises a plastic film, and a single-or multi-layer, thin metal film formed on at least one surface of the plastic film, the thin metal film being provided with large numbers of substantially parallel, intermittent, linear scratches with irregular widths and intervals in plural directions. Its production apparatus comprises pluralities of pattern rolls each having large numbers of fine, high-hardness particles on the surface, which are arranged to form linear scratches on the thin metal film side of a thin metal film-plastic composite film, and means each pressing the pattern roll to the composite film, and pluralities of the pattern rolls being oriented in different directions in a plane in which they are in sliding contact with the thin metal film of the composite film.

The invention provides an absorption-rate-adjustable bandwidth electromagnetic wave absorber based on a graphene film, and aims to solve the technical problems of high cost and poor practicability in the conventional absorption-rate-adjustable bandwidth electromagnetic wave absorber based on the graphene film. The absorption-rate-adjustable bandwidth electromagnetic wave absorber comprises a conductive layer and a dielectric layer which are laminated one above the other, wherein the conductive layer comprises a metal patch and a graphene film attached to the lower surface of the metal patch; a plurality of cross-shaped gaps of different forms are etched into the metal patch to form M*N patch units; each patch unit consists of m*n patches; the dielectric layer comprises a first dielectric plate, a second dielectric plate and a third dielectric plate which are laminated from top to bottom; a bottom plate is printed on the lower surface of the third dielectric plate; a direct-current power supply is connected between the graphene film and the second dielectric plate, and is used for adjusting surface conductivity of the graphene film. The absorption-rate-adjustable bandwidth electromagnetic wave absorber has the advantages of low cost and high practicability, and can be applied to occasions requiring an intermittent wave-absorbing feature such as a paraboloid antenna and an aircraft surface.

The present invention provides a flame-retardant electromagnetic wave absorber that exhibits excellent formability and electromagnetic wave-absorbing properties, and can be easily assembled and constructed. The electromagnetic wave absorber comprises a wave-absorbing body and a base plate supporting the bottom thereof, wherein the wave-absorbing body is formed in a pyramid shape by fitting polygonal wave-absorbing plates into each other.

An electromagnetic-wave-absorbing film comprising a plastic film, and a single- or multi-layer, thin metal film formed on at least one surface of the plastic film, the thin metal film being provided with large numbers of substantially parallel, intermittent, linear scratches with irregular widths and intervals.

The invention provides a multilayer type electromagnetic wave absorber which comprises (a) two surface layers and (b) an intermediate layer, wherein the two surface layers mainly comprise a glass-coated yarn wave absorbent and a polymer substrate; the intermediate layer is positioned between the surface layers, and the intermediate layer mainly comprises a flat type amorphous alloy powder wave absorbent and a polymer substrate. The invention also provides a method for preparing the multilayer type electromagnetic wave absorber.

A multi-directional resonant-type electromagnetic wave absorber includes: at least one ground layer; a first dielectric layer and a second dielectric layer respectively formed on different outer surfaces of the ground layer; a first resistive pattern layer formed on an outer surface of the first dielectric layer; and a second resistive pattern layer formed on an outer surface of the second dielectric layer. Herein, the electromagnetic absorption performance is adjusted by changing one or more of thicknesses, permittivities, and permeabilities of the dielectric layers, thicknesses of the resistive pattern layers, and a reflection coefficient of the ground layer.

The present invention relates to a structure of an antenna and its shielding structure for a mobile phone which may significantly reduce the hazardous electromagnetic wave transmitted to the user's body. The present invention arranges a monopole antenna inside of the mobile phone housing, and installs an electromagnetic wave absorber between the antenna and the circuit board. The electromagnetic wave absorber can absorb the electromagnetic wave reflected form conductive plate constituting the circuit board. Thus, the adverse effect of the reflected electromagnetic wave to the performance of antenna is prevented and the amount of the electromagnetic wave to which the users is exposed can be significantly reduced as well.

Disclosed are an electromagnetic wave absorber using a dielectric loss sheet, a method for fabricating the same, and a wind turbine blade having an electromagnetic wave function. The electromagnetic wave absorber comprises: a support layer for providing a resonant space of electromagnetic waves; a highly conductive backing layer assigned to a back surface of the dielectric support layer; and a dielectric lossy composite sheet layer formed on a front surface of the dielectric support layer, said dielectric lossy composite sheet layer having such a dielectric permittivity so as to generate a resonant peak with the electromagnetic waves reflected from the highly conductive backing layer.

An electromagnetic wave absorber characterized by comprising from 50 to 85% by weight of inorganic hollow material, from 0.01 to 35% by weight of conductive material, from 5 to 47.5% by weight of binder, and from 0.1 to 47.5% by weight of filler. It has a reduced angle dependence of electromagnetic wave absorption and has the property of absorbing electromagnetic waves over a wide range of angles. It further has satisfactory processability and workability.

Disclosed is an electromagnetic wave absorbent which exhibits high electromagnetic wave absorption performance over a wide band. The electromagnetic wave absorbent contains a conductive fiber sheet which is obtained by coating a fiber sheet base with a conductive polymer and has a surface resistivity within a specific range. The conductive fiber sheet is formed by impregnating a fiber sheet base such as a nonwoven fabric with an aqueous oxidant solution that contains a dopant, and then bringing the resulting fiber sheet base into contact with a gaseous monomer for a conductive polymer, so that the monomer is oxidatively polymerized thereon.

A solid state imaging device is constituted of an image sensor chip, a circuit board, and an electromagnetic-wave absorber formed of copper. The image sensor chip is constituted of a bare chip, a spacer, and a cover glass. First contact terminals are formed on the bare chip, and second contact terminals and GND wires are formed on the circuit board. When manufacturing, the image sensor chip is mounted at a predetermined position on the circuit board, and the first contact terminals and the second contact terminals are connected with bonding wires. The electromagnetic-wave absorber is formed to cover the bonding wires, while its end contacts to the GND wires.

The invention relates to a near infrared absorber based on a graphene/metal nanometer belt structure and belongs to a perfect electromagnetic wave absorber. When incoming wave irradiates a metal nanometer belt array, the magnetic resonance effect is excited by the incoming wave at the metal nanometer belt, energy of the incoming wave is substantially enhanced at a gap of the metal nanometer belt, after upper and lower portions of the metal nanometer belt are respectively added with a graphene layer, electromagnetic wave energy is enhanced, the upper and lower graphene layer effect is enhanced, absorption is further carried out, and the resonance wavelength electromagnetic wave energy is integrally absorbed in a perfect mode. The near infrared absorber is advantaged in that five structure layers are comprised, sequentially comprising a substrate (1), an insulation layer (2), the first graphene layer (3), the metal nanometer belt (4) and the second graphene layer (5), and the specific wavelength can be absorbed to a nearly perfect degree through adjusting structural geometric parameters.

A nonreflective waveguide terminator includes a waveguide portion and an electromagnetic wave absorber. The portion has a rectangular opening in a plane perpendicular to a radio-wave propagation direction. The portion has one open end in the direction and the other end closed by a terminating metal internal wall. The portion has a radio-wave propagation space surrounded by first and second metal internal walls parallel to a radio-wave electric field, and third and fourth metal internal walls perpendicular to the field. The exterior shape of the absorber is a parallelepiped. The absorber has a rear-end surface positioned at a predetermined distance from the terminating wall and parallel to the terminating wall or is provided against the terminating wall. The surface of the absorber having the largest rectangular area is on the third or the fourth metal internal wall.

An electromagnetic wave absorber for use in the high frequency range above 1 Ghz and a composite member are characterized by the fact that magnetic metal grains are covered with ceramic above 20 volume %. Further, a method of manufacturing the electromagnetic absorber and the composite member is characterized by the fact that composite magnetic particles, in which a plurality of magnetic metal grains and ceramic are unified, are formed through a mechanical alloying method applied to a composite powder composed of magnetic metal powder and ceramic powder. The electromagnetic wave absorber can be used in a semiconductor device, an optical sending module, an optical receiving module, an optical sending and receiving module, an automatic tollgate in which erroneous operation due to electromagnetic wave disturbance is provided by use of the electromagnetic wave absorber.

An electromagnetic wave absorber comprises an electromagnetic wave absorber molded element, plate-shaped sintered ferrite, and a metal plate. The molded element incorporates a tile-shaped base portion and a wedge-shaped apex portion disposed on the base portion. The molded element is formed by injecting slurry into a mold, the slurry being obtained through mixing a molding material for the wave absorber with water, and curing the slurry. The molding material includes a magnetic material, an inorganic fiber and an inorganic binder. When these ingredients are mixed with water, the molding material first exhibits fluidity and then a curing reaction in a temperature range of 1 to 40° C.