An electromagnetic-wave shielding sheet is an electromagnetic-wave shielding sheet used to form an electronic component-mounted substrate, the electronic component-mounted substrate including an electromagnetic-wave shielding layer covering at least a part of a step part and an exposed surface of a substrate, in which the electromagnetic-wave shielding sheet is a laminate including a cushion layer and a conductive layer, the conductive layer is an isotropic conductive layer containing a binder resin and a conductive filler, a thickness of the conductive layer is 8 to 70 μm, and a content of the conductive filler in a region on a side opposite to a cushion layer side in the conductive layer is larger than that in a region on the cushion layer side in the conductive layer.

A filter assembly is disclosed that includes a monolithic filter having a surface and a heat sink coupled to the surface of the monolithic filter. The heat sink includes a layer of thermally conductive material that can have a thickness greater than about 0.02 mm. The heat sink may provide electrical shielding for the monolithic filter. In some embodiments, the filter assembly may include an organic dielectric material, such as liquid crystalline polymer or polyphenyl ether. In some embodiments, the filter assembly may include an additional monolithic filter.

An electromagnetic wave transmission cable for transmitting an electromagnetic wave comprises a hollow waveguide tube and a foamed resin member. The hollowing waveguide tube includes a hollow dielectric layer formed in a tubular shape. The foamed resin member is provided over a predetermined length in a longitudinal direction of the hollow waveguide tube and covers a surface of the dielectric layer to surround an outer periphery of the hollow waveguide tube.

A leakage magnetic field shielding device includes: a leakage magnetic field determining unit for determining phase and magnitude of a leakage magnetic field based on information obtained from a power supply device and a current collector device; a shielding current controller for determining a shielding current based on the phase and magnitude of the leakage magnetic field and supplying the determined shielding current to the leakage magnetic field shielding device; and a shielding unit for shielding the leakage magnetic field by generating a shielding magnetic field in accordance with the supply of the shielding current. The shielding unit has a multiple resonance characteristic depending on an arrangement of capacitors and coils and is disposed to surround the power supply device or the current collector device. The shielding magnetic field has resonance frequencies canceling magnetic fields corresponding to fundamental frequency and multiple frequency of the leakage magnetic field.

An electromagnetic wave transmission board includes a composite board and a plated metal layer. The composite board has a plurality of inner walls surroundingly defining an elongated channel in an interior of the composite board. The plated metal layer is formed on at least part of the inner walls so as to jointly form an inner channel structure in the channel. The inner channel structure surroundingly defines a predetermined space filled with air, and the inner channel structure has two entrances in air communication with the predetermined space. The predetermined space of the inner channel structure is configured to receive and output an electromagnetic wave signal through the two entrances, respectively, and the electromagnetic wave transmission board is configured to transmit the electromagnetic wave signal by using the air in the predetermined space of the inner channel structure as a conductive medium.

Electromagnetic shields for sub-modules of electronic modules are disclosed. Electronic modules may include multiple sub-modules arranged on a substrate with an electromagnetic shield arranged to conformally cover the sub-modules as well as portions of the substrate that are uncovered by the sub-modules. Electromagnetic shields are disclosed that are configured to extend between sub-modules to form one or more divider walls. The one or more divider walls may be configured to extend below mounting surfaces of electronic components in the sub-modules to provide improved reduction of electromagnetic interference (EMI) or crosstalk between various sub-modules. Electromagnetic shields are also disclosed that form perimeter sidewalls that extend below mounting surfaces of electronic components of sub-modules to provide improved reduction of EMI from other modules or other external sources.

Various circuit board systems and methods of use and manufacture thereof are disclosed. A circuit board system can have a first circuit board including a substrate and a first component susceptible to electromagnetic interference carried by the substrate. The system can also include a second circuit board including a second substrate, and a shield engaged to the substrate of the first component, the shield at least partially covering the first component and being configured to protect the first component from electromagnetic interference, wherein the shield couples the substrate of the first circuit board to the substrate of the second circuit board.

Disclosed are an embedded co-cured composite material with large-damping and electromagnetic wave absorbing properties and a preparation method and an application thereof, belonging to damping composite materials. The embedded co-cured composite material is formed by interlacing a plurality of electromagnetic wave absorbing prepreg layers and a plurality of electromagnetic wave absorbing damping layers. Each of the electromagnetic wave absorbing prepregs layers includes a fiber cloth, a micro-nano electromagnetic wave absorbing material and a resin. Contents of the micro-nano electromagnetic wave absorbing material in the electromagnetic wave absorbing prepreg layers and the electromagnetic wave absorbing damping layers have a gradient increase or decrease according to a sequence of the electromagnetic wave absorbing prepreg layers. Each of the electromagnetic wave absorbing damping layers includes a viscoelastic damping material and the micro-nano electromagnetic wave absorbing material.

An active electromagnetic interference (EMI) filter includes a first amplifier and a second amplifier. The first amplifier is configured to sense noise signals on a power conductor. The second amplifier is coupled to the first amplifier and is configured to drive a cancellation signal onto the power conductor. The cancellation signal is to reduce the amplitude of the noise signals sensed by the first amplifier. An output impedance of the second amplifier is lower than an output impedance of the first amplifier.

Various circuit board systems and methods of use and manufacture thereof are disclosed. A circuit board system can have a first circuit board including a substrate and a first component susceptible to electromagnetic interference carried by the substrate. The system can also include a second circuit board including a second substrate, and a shield engaged to the substrate of the first component, the shield at least partially covering the first component and being configured to protect the first component from electromagnetic interference, wherein the shield couples the substrate of the first circuit board to the substrate of the second circuit board.