An LC circuit includes a first capacitor provided between a first connection point and a second connection point, a second capacitor provided between the second connection point and a third connection point, a third capacitor provided between the third connection point and a fourth connection point, a fourth capacitor provided between the first connection point and the third connection point, a fifth capacitor provided between the second connection point and the fourth connection point, a first inductor connected to the second connection point, and a second inductor connected to the third connection point.

A filter device includes a first filter including series resonators and parallel resonators, a first inductor connected in parallel between a first terminal and the first filter, a second inductor provided in series between the first filter and a second terminal, and a third inductor provided in series in a channel connecting the parallel resonator and ground, the third inductor is incorporated in a multilayer substrate, the first filter is mounted on a main surface of the multilayer substrate and incorporated in a filter chip, and the first inductor and the second inductor are chip inductors including coil conductors and are mounted on the main surface of the multilayer substrate beside the filter chip so as to be adjacent to each other and such that coil axes thereof are orthogonal or substantially orthogonal to each other.

A first filter is a hybrid filter including an acoustic wave filter, a plurality of first inductors, and a plurality of first capacitors. A high frequency module further includes a metal electrode layer covering at least part of a resin layer and at least part of an outer peripheral surface of a mounting substrate. Among a plurality of inductors including the plurality of first inductors of the first filter and a plurality of second inductors of a second filter, at least one inductor (the second inductor) is a circuit element including a conductor pattern portion formed in the mounting substrate. The shortest distance between the outer peripheral surface of the mounting substrate and a signal terminal (a third signal terminal) connected to the circuit element is longer than the shortest distance between the outer peripheral surface of the mounting substrate and the circuit element.

In a radio-frequency module, a hybrid filter includes an acoustic wave filter including at least one acoustic wave resonator, an inductor having a winding portion, and a capacitor. A plurality of outer electrodes of the acoustic wave filter includes a first input and output electrode connected to a first signal terminal, a second input and output electrode connected to a second signal terminal, and a ground electrode connected to a ground terminal. The inductor is disposed on a first major surface of a mounting substrate and is adjacent to the acoustic wave filter in plan view in a thickness direction of the mounting substrate. When viewed in a direction of a winding axis of the winding portion of the inductor, an inner part of the winding portion in the inductor does not overlap any of the first input and output electrode, the second input and output electrode, and ground electrode.

Multiplexing circuits with bulk acoustic wave (BAW) resonators as network elements for higher performance are provided. Multiplexing networks which support newer fourth generation (4G) and fifth generation (5G) standards may include a combination of multiplexers having a number of radio frequency (RF) filters connected to an antenna at the same time. One critical aspect of such a multiplexer design is the loading of these filters to each other, in which the static capacitance presented by a filter can be beneficial or detrimental to other filters in the multiplexing network. Aspects of the present disclosure introduce a BAW resonator to improve multiplexing network performance using the frequency-dependent capacitance, resonance, and/or anti-resonance of the BAW resonator.

A signal processing system includes: an interference source; and a band-stop filter. A first terminal of the band-stop filter is electrically connected to the interference source, a second terminal of the band-stop filter is grounded, and the band-stop filter is configured to filter a baseband signal output by the interference source. The interference source includes a first main board; or the interference source includes a target module and a metal frame used for fastening the target module, and the target module is a display module or a camera module.

Aspects of this disclosure relate to a multiplexer with a hybrid acoustic passive filter. The multiplexer includes a plurality of filters configured to filter respective radio frequency signals, a shared filter coupled between each of the plurality of filters and a common node, and a radio frequency filter coupled to the common node. At least a first filter of the plurality of filters includes acoustic resonators and a non-acoustic passive component. Related multiplexers, wireless communication devices, and methods are disclosed.

An EMI/energy dissipating filter for an active implantable medical device (AIMD) comprises a first gold braze sealing an insulator to the ferrule of a glass-to-metal seal (GTMS) and a lead wire that is sealed in a passageway through the insulator by a second gold braze. A circuit board is disposed adjacent to the insulator. A two-terminal chip capacitor disposed adjacent to the circuit board has an active end metallization connected to its active electrode plates and a ground end metallization connected to its ground electrode plates. A ground electrical path extends from the ground end metallization of the chip capacitor, through a circuit board ground plate disposed on or within the circuit board, and to the ferrule. An active electrical path extends from the active end metallization of the chip capacitor to the lead wire of the GTMS.

A radio frequency (RF) integrated circuit may include a die having passive components including at least one pair of capacitors covered by a first dielectric layer supported by the die. The RF integrated circuit may also include an inline pad structure coupled to the at least one pair of capacitors proximate an edge of the die. The inline pad structure may include a first portion and a second portion extending into a dicing street toward the edge of the die and covered by at least a second dielectric layer.

A filter includes a first resonance circuit including a first capacitor and a first inductor connected in parallel between a ground terminal and a first node electrically connected to a first signal terminal not through any capacitor, no inductor being connected in series with the first capacitor between the first node and the ground terminal, a second resonance circuit including a second capacitor and a second inductor connected in parallel between the ground terminal and a second node electrically connected to a second signal terminal not through any capacitor, and a third resonance circuit including a third capacitor and a third inductor connected in parallel between a third node, located in a path through which a high-frequency signal is transmitted between the first and second nodes, and the ground terminal, and a first series inductor connected in series with the third capacitor between the third node and the ground terminal.