A filter device configured to directly connect to a differential power amplifier of a transmit chain circuit. The filter device may include a transformer and a filter configured as a half lattice equivalent topology and having a single-ended output. The filter may be a lattice filter configured as a full lattice topology or a lattice equivalent filter configured as a half lattice equivalent topology. The filter includes a first branch having a first impedance network of one or more first impedance elements and a second branch having a second impedance network of one or more second impedance elements. The single-ended output of the filter device may connect to an antenna switch that is in turn connected to an antenna.

Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

Examples described herein provide selective filtering by a network device for continuous 5 GHz and 6 GHz operation. Examples may include receiving, by the network device, a first signal in a 5 GHz band, and generating, by the network device, a second signal in a 6 GHz band. Examples may include selecting, by the network device, a first filter or a second filter to be applied the first signal in the 5 GHz band, wherein the first filter allows a lower frequency band to pass than the second filter in the 5 GHz band, selecting, by the network device, a third filter or a fourth filter to be applied to the second signal in the 6 GHz band, wherein the third filter allows a lower frequency band to pass than the fourth filter in the 6 GHz band, and simultaneously applying, by the network device, the selected first or second filter to the first signal and the selected third or fourth filter to the second signal.

An electronic component includes: a first substrate having a first surface; a second substrate having a second surface facing the first surface across an air gap; a first coil pattern that is located on the first surface so as to face the second surface across the air gap; a second coil pattern that is located in a second region on the second surface and faces the first surface across the air gap, at least a part of the second region overlapping with a first region in plan view, the first region being formed of a region in which the first coil pattern is located and a region surrounded by the first coil pattern; and a connection terminal connecting the first coil pattern and the second coil pattern.

A BAW resonance device, a filter device and an RF front-end device are provided. The BAW resonance device comprises a first passive part including a first substrate and a first heat-dissipation layer located over the first substrate; a first active part including a first piezoelectric layer, a first electrode layer and a second electrode layer, wherein the first piezoelectric layer is located over the first passive part and has a first side and a second side opposite to the first side, the first passive part is located on the first side, the first electrode layer is also located on the first side and is disposed between the first passive part and the first piezoelectric layer, and the second electrode layer is located on the second side; and a first cavity located on the first side and disposed between the first passive part and the first piezoelectric layer, wherein at least one part of the first electrode layer is located on or in the first cavity. The first heat-dissipation layer can improve or flexibly adjust the heat-dissipation performance of the SAW resonance device.

A multiplexer includes acoustic wave filters that are electrically connected to a common connection terminal. In a first transmission-side filter of the acoustic wave filters, a series arm resonator closest to the common connection terminal includes acoustic wave resonators that are electrically connected in series and capacitance elements that are electrically connected between at least one of signal paths electrically connecting the acoustic wave resonators to each other and a reference terminal.

Systems and methods for tuning multiplexer filters are disclosed. In one aspect, a multiplexer includes a first filter coupled to a common node, the first filter configured to pass a first band, a second filter coupled to the common node, the second filter configured to pass a second band, and at least one electrical component configured to generate a notch at a frequency between the first band and the second band.

Systems and methods for tuning multiplexer filters are disclosed. In one aspect, a multiplexer includes a first filter coupled to a common node, the first filter configured to pass a first band, a second filter coupled to the common node, the second filter configured to pass a second band, and at least one electrical component configured to generate a notch at a frequency between the first band and the second band.

Aspects of this disclosure relate to a multiplexer with an acoustic assisted trap circuit. The multiplexer includes an acoustic wave filter with an acoustic wave resonator and an impedance network that together provide a trap for a harmonic associated with another acoustic wave filter of the multiplexer. The acoustic wave filter can have an edge of a passband that is farther from the harmonic than other acoustic filters of the multiplexer.

A multiplexer includes a first transmission filter connected to a common terminal, a reception filter, a second transmission filter, and a multilayer substrate. The first transmission filter includes a first parallel-arm resonator connected to a first parallel-arm terminal and a second parallel-arm resonator connected to a second parallel-arm terminal. The second transmission filter includes a third parallel-arm resonator connected to a third parallel-arm terminal and a fourth parallel-arm resonator connected to a fourth parallel-arm terminal. The first to fourth parallel-arm resonators are surface-mounted on a main surface of the multilayer substrate. The second and third parallel-arm terminals are grounded on any dielectric layer from the main surface to an n-th dielectric layer of the multilayer substrate and the first and fourth parallel-arm terminals are isolated from each other on the dielectric layers from the main surface to the n-th dielectric layer.