A transformer includes: a magnetic core including a lower magnetic structure and an upper magnetic structure; a printed circuit board arranged between the lower magnetic structure and the upper magnetic structure and including a core hole through which a midsection of the magnetic core penetrates, a primary coil, a secondary coil, a primary via-hole formed at an end of the printed circuit board and electrically connected to the primary coil, and a secondary via-hole formed at another end of the printed circuit board and electrically connected to the secondary coil; a primary pin inserted into the primary via-hole; a secondary pin inserted into the secondary via-hole; an insulating block into which a portion of the printed circuit board is inserted; and a mount on which the printed circuit board and the insulating block are mounted.

A radio frequency apparatus includes a power amplifier circuit, a signal coupling circuit, an extraction circuit, and a harmonic filter circuit. The power amplifier circuit is configured to amplify a differential signal to output a to-be-filtered signal. The signal coupling circuit includes a primary side inductor and a secondary side inductor. The signal coupling circuit is configured to convert the to-be-filtered signal received by the primary side inductor into a single-ended signal outputted from the secondary side inductor. The extraction circuit has a center tap. The extraction circuit is configured to inductively couple to the primary side inductor and output a common mode signal from the center tap. The harmonic filter circuit is configured to perform a harmonic filtering on the single-ended signal according to the common mode signal, such that the secondary side inductor of the signal coupling circuit outputs a filtered signal.

An inductor device includes a first inductor, a second inductor, and at least one switch circuit. The second inductor is arranged to enclose the first inductor, and use a topmost layer metal to resist external interference for the first inductor. The at least one switch circuit is coupled to the second inductor, and is arranged to receive at least one control voltage, wherein the at least one control voltage is arranged to adjust conduction degree of the at least one switch circuit.

A multilayer coil component includes a base body containing magnetic metal particles, and a coil embedded in the base body. The coil includes a plurality of inner electrode layers containing silver, and the inner electrode layers include a first inner electrode layer having a high pore area ratio and a second inner electrode layer having a low pore area ratio.

A magnetic powder contains a magnetic metal particle comprising iron (Fe) and an insulating coating layer disposed on a surface of the magnetic metal particle and comprising tin (Sn), phosphorous (P) and oxygen (O), and a coil component contains such a magnetic powder.

An inductor unit includes a conductive structure, a first magnetic element and an insulating layer. The conductive structure has a bottom conductive layer, a top conductive layer, and a first side conductive layer extending from the bottom conductive layer to the top conductive layer. The first magnetic element is disposed on the bottom conductive layer of the conductive structure. The insulating layer is disposed on the bottom conductive layer of the conductive structure, wherein the insulating layer covers and surrounds the first magnetic element. The circuit structure including the inductor unit and the methods for manufacturing the same are also provided.

A magnetic part including: a coil that generates a magnetic flux when a current flows through the coil; a core that is formed of a magnetic substance that forms a magnetic path of the magnetic flux; a support member that supports the core; and a fixing member that fixes the core to the support member. The core includes a column portion that is vertically provided with respect to a surface where the core is in contact with the support member. The fixing member presses the column portion of the core against the support member. The support member has a recess in a portion of a facing surface that faces the core, where the portion of a facing surface does not face the column portion.

An electromagnetic device for converting energy comprises: a ferromagnetic core of essentially planar shape and delimited by a peripheral contour; a primary winding and a secondary winding formed by primary turns and secondary turns, respectively. The device includes, arranged against the peripheral contour, a first block and a second block and a ferromagnetic material, and has a magnetic permeability lower than that of the ferromagnetic core. At least one primary turn and/or at least one secondary turn is formed around or passing through the first block and/or the second block to form, respectively, a first leakage inductance and/or a second leakage inductance.

A signal transmission circuit for transmitting an insulation signal includes: a multilayer substrate including a plurality of layers; and a pattern transformer disposed on the multilayer substrate. The pattern transformer includes a primary winding having a wound printed pattern wiring provided in each of a first plane region and a second plane region of the multilayer substrate, and a secondary winding disposed at a different position from the primary winding in a layer direction and having a wound printed pattern wiring provided in each of the first plane region and the second plane region of the multilayer substrate. The primary winding and the secondary winding are electromagnetically coupled and configured such that a current flows clockwise through one of the wound printed pattern wiring provided in the first plane region or the wound printed pattern wiring provided in the second plane region while a current flows counterclockwise through the other.

A filter device includes an input terminal, an output terminal, a main body, a common electrode provided to the main body, a ground terminal, and LC parallel resonators connected to the common electrode and the ground terminal. Each LC parallel resonator includes a capacitor, a first via, and a second via. One end of the first via is connected to the common electrode, and another end thereof is connected to the ground terminal through the capacitor. One end of the second via is connected to the common electrode, and another end thereof is connected to the ground terminal without through the capacitor. The second via is connected between portions of the common electrode to which the first vias of two adjacent resonators are connected.