Aspects of the disclosure relate to wireless communication filtering. One aspect is an apparatus including a first acoustic resonator that is part of a first bandpass filter having a first passband and coupled to a circuitry connection port and a communication connection port, and a second acoustic resonator that is part of one of a second bandpass filter or a notch filter. The apparatus further includes a third acoustic resonator that is part of the first bandpass filter, and a fourth acoustic resonator that is part of the second bandpass filter or the notch filter.

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.

An acoustic wave device includes: a piezoelectric substrate bonded on a support substrate, a surface including protruding portions and/or recessed portions being interposed between the piezoelectric substrate and the support substrate; a first acoustic wave resonator that includes first electrode fingers with a first average pitch and is disposed on the piezoelectric substrate in a first region where an average interval between the protruding portions and/or the recessed portions in a direction in which the first electrode fingers are arranged is a first interval; and a second acoustic wave resonator that includes second electrode fingers with a second average pitch different from the first average pitch, and is disposed on the piezoelectric substrate in a second region where an average interval between the protruding portions and/or the recessed portions in a direction in which the second electrode fingers are arranged is a second interval different from the first interval.

A high-frequency module includes a module substrate including an internal wiring pattern, and a SAW filter including a piezoelectric substrate, an electrode pattern on the piezoelectric substrate, a support surrounding the electrode pattern, and a cover on the support covering the electrode pattern to define a hollow space together with the support and the piezoelectric substrate. The module substrate, the cover, and the piezoelectric substrate are disposed in this order in a perpendicular or substantially perpendicular direction with respect to the module substrate, and a shield electrode is provided on a surface of the cover that faces the module substrate or on a surface of the cover that faces the piezoelectric substrate.

An acoustic wave device includes a silicon substrate, a first high-acoustic-velocity film on the silicon substrate, a first low-acoustic-velocity film on the first high-acoustic-velocity film, a second low-acoustic-velocity film on the first low-acoustic-velocity film, a second high-acoustic-velocity film on the second low-acoustic-velocity film, a piezoelectric film on the second high-acoustic-velocity film, and an IDT electrode on the piezoelectric film. Acoustic velocities of bulk waves propagating through the first and second high-acoustic-velocity films are higher than an acoustic velocity of an acoustic wave propagating through the piezoelectric film. Acoustic velocities of bulk waves propagating through the first and second low-acoustic-velocity films are lower than an acoustic velocity of a bulk wave propagating through the piezoelectric film. Materials of the first and second low-acoustic-velocity films are different from each other.

In an acoustic wave device, a piezoelectric body is directly or indirectly provided on a high acoustic velocity material layer, an interdigital transducer electrode is directly or indirectly provided on the piezoelectric body, the interdigital transducer electrode includes a first busbar, a second busbar spaced away from the first busbar, a plurality of first electrode fingers, and a plurality of second electrode fingers, and a weighting is applied to the interdigital transducer electrode by providing a floating electrode finger not electrically connected to the first busbar or the second busbar or applied by providing an electrode finger formed by metallizing a gap between the first electrode fingers or a gap between the second electrode fingers to integrate the first electrode fingers or the second electrode fingers.

A method of making a surface acoustic wave package includes bonding a piezoelectric layer over a substrate and attaching a metal structure over the substrate, with the piezoelectric layer positioned between at least a portion of the substrate and at least a portion of the metal structure. The method also includes removing (e.g., etching) an outer boundary of the piezoelectric layer so that a resulting outer edge of the piezoelectric layer is spaced inward of an inner edge of the metal package (e.g., the piezoelectric layer does not contact the metal package). The method inhibit damage to the piezoelectric layer due to a stress differential between the substrate and the thermally conductive structure during a packaging process.

An interdigital transducer increased propagation frequency and a method for making the same is described. The transducer comprises a substrate for propagation of acoustic waves comprising a first surface having alternating high and low surface portions extending laterally across the substrate, a set of elongate first electrodes, each first electrode disposed on a respective high surface portion and a set of elongate second electrodes, each second electrode disposed on a respective low surface portion such that the first and second electrodes are alternately adjacent to one another, the high and low surface portions being substantially equal in width to each electrode of the first and second sets of electrodes.

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.

Acoustic wave resonators are disclosed that include a piezoelectric layer and an interdigital transducer electrode over the piezoelectric layer. The interdigital transducer electrode has a rotation angle and a tilt angle. The rotation angle and the tilt angle can together increase a figure of merit of the acoustic wave device. The rotation angle and the tilt angle can both be non-zero.