An adjustable inductor including a toroidal core defining a plurality of gaps, a compressible gap material positioned in the gaps, at least one winding wound on the core, a force-applying structure, and a film substantially covering the adjustable inductor. The force-applying structure is operable to apply a force to the core to adjust the gaps and thereby an inductance of the adjustable inductor. The film is configured to prevent movement of force-applying structure when above a predetermined temperature threshold, and allow movement of the force-applying structure when below the predetermined threshold.

A high-frequency circuit includes: a diplexer that is composed of a filter which has a pass band including a first frequency band group and a filter which has a pass band including a second frequency band group; a notch filter that is connected with the filter and whose stop band is a frequency band which is not included in a first communication band; a notch filter that is connected with the filter and whose stop band is a frequency band which is not included in a second communication band; and switches that are connected with the notch filters. A band pass filter whose pass band is the first communication band and a band pass filter whose pass band is the second communication band are not connected between the filter and the switches.

An LLC converter includes a resonant network including a resonant capacitance element, a resonant inductance element, and an excitation inductance circuit. The excitation inductance circuit includes a capacitance element and an inductance element connected in series. The minimum operating frequency of the LLC converter is higher than the resonant frequency of the capacitance element and the inductance element.

An electronic component includes a stack and an inductor wound about an axis orthogonal to a stacking direction. The inductor includes a first conductor layer portion and two through hole columns. The first conductor layer portion includes two conductor layers disposed at positions different from each other in the stacking direction and connected in parallel to each other. Area of a first conductor layer is larger than area of a second conductor layer.

An electronic component includes a stack and first to third inductors. Area of a region obtained by perpendicularly projecting a first space including a first axis and surrounded by the first inductor onto an XZ plane is larger than area of a region obtained by perpendicularly projecting a second space including a second axis and surrounded by the second inductor onto a YZ plane. The third inductor is disposed such that a third axis does not intersect the first space but intersects the second space.

An electronic component includes a stack and first to fourth inductors. The second inductor is disposed after the first inductor in a −Y direction. The third inductor and the fourth inductor are disposed after the first inductor and the second inductor, respectively, in a −X direction. Two or more through hole columns are connected in parallel to a part near each end of a conductor layer portion in each of the first inductor and the fourth inductor in a longitudinal direction. One through hole column is connected to a part near each end of a conductor layer portion in each of the second inductor and the third inductor in a longitudinal direction.

An electronic component includes a stack and first and second inductors. The first inductor includes a first through hole column, a second through hole column, a first conductor layer portion, a second conductor layer portion, and a third conductor layer portion. The second conductor layer portion is connected to an end of the first through hole column and extends close to the second through hole column. The third conductor layer portion is connected to the second through hole column and extends close to the first through hole column.

A filter structure includes a ground plane in a first metal layer of an integrated circuit (IC) package, a plate in a second metal layer of the IC package, a dielectric layer between the ground plane and the plate, the ground plane, the dielectric layer, and the plate thereby being configured as a capacitive device, and an inductive device in a third metal layer of the IC package. The inductive device is electrically connected to the plate, and the plate and the inductive device are configured to have a resonance frequency greater than 1 GHz.

A radio frequency filter is provided and includes a dielectric layer and a first inductor. The first inductor includes an input, a first coil disposed on a first side of the dielectric layer and connected to the input, and a second coil disposed on a second side of the dielectric layer opposite the first side. The first and second coils are planar, such that windings of the first coil are in a first layer and windings of the second coil are in a second layer. The first coil overlaps and is connected in series with the second coil. The first coil, the dielectric layer and the second coil collectively provide a capacitance of the radio frequency filter. The first inductor further includes a first via extending through the dielectric layer and connected to the first coil and the second coil and a first output connected to the second coil.

The integrated circuit includes a power amplifier intended to provide a signal in a fundamental frequency band, an antenna, and a matching and filtering network having a first section, a second section, and a third section. The three sections include LC arrangements configured to have an impedance matched to the power amplifier's output in the fundamental frequency band. The LC arrangements of the first section and the second section are configured to have resonant frequencies adapted to attenuate the harmonic frequency bands of the fundamental frequency band.