An inductor is provided, comprising: a first ferrite core piece and a second ferrite core piece, each of which are made of substantially similar materials, exhibit desired electromagnetic properties, and which are fashioned in a substantially similar manner and shape, and wherein each of the first and second ferrite core pieces comprises a substantially planar mating surface, a center post, and a wire core assembly channel, and wherein a first substantially planar mating surface of the first ferrite core piece is adapted to planarly mate with a second substantially planar mating surface of the second ferrite core piece; and a wire core assembly adapted to be substantially self-locating and self-centering about a first or second center post when located in a respective first or second wire core assembly channel.

A common-mode choke coil includes a first filter unit and a second filter unit, each of which serves as a common-mode filter unit and is formed by arranging a primary coil and a secondary coil in a stacking direction. Of the first filter unit and the second filter unit, the first filter unit has a resonant frequency different from that of the second filter unit, and the line length is different between the primary coil and the secondary coil.

A common-mode choke coil comprises a ferrite core including a winding core portion and first and second flange portions. The common-mode choke coil also comprises first and second wires, each of which is helically wound around the winding core portion. The common-mode choke coil further comprises first and second terminal electrodes to which a first end of the first wire and a second end of the first wire, that is opposite the first end, are electrically connected, respectively. In addition, the common-mode choke coil comprises third and fourth terminal electrodes to which a first end of the second wire and a second end of the second wire, that is opposite the first end, are electrically connected, respectively. A common-mode inductance value at 150 C. and 100 kHz is 160 H or more, and a return loss at 20 C. and 10 MHz is 27.1 dB or less.

An electromagnetic device includes a substrate, magnetic cores, transmission line layers, and conductive members. The substrate is provided with annular receiving grooves for accommodating the magnetic cores; the substrate is divided into a central portion and a peripheral portion; inner and outer via holes are respectively formed on the central portion and the peripheral portion, respectively; the transmission line layers each including wire patterns are respectively provided on opposite sides of the substrate; and the conductive members are sequentially connected to the wire patterns on both sides of the substrate to form a transformer and/or a filter; the electromagnetic device has a first side provided with a slot and a second side parallel to the transmission line layers; and first conductive pins electrically connected to the at least one transmission line layers are provided on at least one of the side wall surrounding the slot and a second side.

Disclosed herein is a common mode filter that includes a winding core part and first and second wires wound in a same direction around the winding core part. A predetermined one turn of the first wire crosses a predetermined one turn of the second wire a plurality of times.

A common mode choke assembly includes a main core, a shunt core, and first and second two-piece bobbins. The main core has a generally rectangular main core body, and first and second core riser portions. The first and second core riser portions are connected to opposite ends of the main core body. The first core riser portion includes a first riser notch and the second core riser portion includes a second riser notch aligned with the first riser notch. The shunt core spans between and is positioned within the first and second riser notches. The first and second two-piece bobbins are positioned on opposite sides of the main core body adjacent to the first and second core riser portions. Each two-piece bobbin includes at least first and second end flanges, a passageway, and a mating surface. The assembly further includes a mounting header for receiving the main and shunt core.

An electromagnetic device includes a substrate, magnetic cores, transmission line layers, and conductive members. The substrate is provided with annular receiving grooves for accommodating the magnetic cores; the substrate is divided into a central portion and a peripheral portion; inner and outer via holes are respectively formed on the central portion and the peripheral portion, respectively; the transmission line layers each including wire patterns are respectively provided on opposite sides of the substrate; and the conductive members are sequentially connected to the wire patterns on both sides of the substrate to form a transformer and/or a filter; the electromagnetic device has a first side provided with a slot and a second side parallel to the transmission line layers; and first conductive pins electrically connected to the at least one transmission line layers are provided on at least one of the side wall surrounding the slot and a second side.

The present disclosure provides a common mode noise filter that can improve attenuation characteristics of common mode noise over a wide frequency range. The common mode noise filter of the present disclosure includes: two magnetic sections and each of which is made of a magnetic material; and non-magnetic section disposed between magnetic sections in a stacking direction, non-magnetic section being made of a non-magnetic material. Moreover, the common mode noise filter further includes two coils and metal layer. Coils are disposed inside non-magnetic section while facing each other. Metal layer is formed inside at least one of two magnetic sections while being connected to the ground. Metal layers are positioned closer to a lower surface of magnetic section than an upper surface of magnetic section and closer to an upper surface of magnetic section than a lower surface of magnetic section.

A filter device includes a plurality of coils of which central axes are spaced apart from one another and in parallel to one another and a plurality of ground members spaced apart from one another and extending in parallel to the central axes of the coils outside of the coils. Each of the coils is spaced apart from another coil closest thereto by a first distance. Each of the ground members is spaced apart from a coil closest thereto by a second distance. The number of ground members spaced apart from each of the coils by the second distance is the same.

In some embodiments, an architecture can include a first group of filters each configured to support a band such that a first frequency range covers the respective bands, and a second group of one or more filters each configured to support a band such that a second frequency range covers the respective one or more bands. Each filter of the first group can be configured to provide an impedance at or near a short circuit impedance for a signal in each band of the second group, and each filter of the second group can be configured to provide an impedance at or near a short circuit impedance for a signal in each band of the first group. The filters of the first and second groups can be implemented as one or more multiplexers. The architecture can further include a coupling circuit having a common node and configured to couple the common node to the one or more multiplexers through a first path and a second path. The coupling circuit can be further configured such that the impedance provided by each filter of the first group for the signal in each band of the second group results in the signal being sufficiently excluded from the first path, and such that the impedance provided by each filter of the second group for the signal in each band of the first group results in the signal being sufficiently excluded from the second path.