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 printed circuit includes a first track, a second track, and at least one insulating layer extending between the first track and the second track. The printed circuit further includes a first through assembly of at least one first plated through hole and a second through assembly of at least one second plated through hole. Each first plated through hole and each second plated through hole connect together the first track and the second track by extending through the insulating layer. The first through assembly and the second through assembly respectively form a first branch and a second branch of a current divider bridge.

A coil-incorporated multilayer substrate includes base materials and a coil portion including conductor patterns that are wound a plurality of times on at least one of the base materials, and, in a predetermined direction along the surface of the base material of the coil portion, the width of outermost conductor patterns is larger than the widths of the conductor patterns between an innermost conductor pattern and an outermost conductor pattern, the width of the innermost conductor pattern is larger than the widths of the conductor patterns between the outermost conductor pattern and the innermost conductor pattern, and the width of the innermost conductor pattern is larger than the distance between the innermost conductor pattern and the conductor pattern adjacent to the innermost conductor pattern.

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.

An inductor structure includes a first inductor and a second inductor. A first portion of the first inductor is disposed on a first layer and a second portion of the first inductor is disposed on a second layer. A first portion of the second inductor is disposed on the first layer and a second portion of the second inductor is disposed on the second layer. The first portion of the first inductor and the second portion of the second inductor at least partially overlap. The second portion of the first inductor and the first portion of the second inductor at least partially overlap.

Methods of coupling inductors in an IC device using interconnecting elements with solder caps and the resulting device are disclosed. Embodiments include forming a top inductor structure, in a top inductor area on a lower surface of a top substrate, the top inductor structure having first and second top terminals at its opposite ends; forming a bottom inductor structure, in a bottom inductor area on an upper surface of a bottom substrate, the bottom inductor structure having first and second bottom terminals at its opposite ends; forming top interconnecting elements on the lower surface of the top substrate around the top inductor area; forming bottom interconnecting elements on the upper surface of the bottom substrate around the bottom inductor area; forming solder bumps on lower and upper surfaces, respectively, of the top and bottom interconnecting elements; and connecting the top and bottom interconnecting elements to each other.

A multilayer coil component includes an inner conductor, a component element assembly including the inner conductor, and outer conductors disposed at respective end portions of the component element assembly. The component element assembly has a first region in which the primary component is composed of a magnetic material and which may contain a nonmagnetic material and second regions which are disposed at respective end portions of the first region and which contain at least a nonmagnetic material. Each second region is disposed having a greater volume content of the nonmagnetic material than the first region such that, for example, the difference in the volume content results about 25% by volume or more. The coil portion of the inner conductor is embedded in the first region, and the length of the second region is greater than or equal to the length of the side-surface folded portion of the outer conductor.