An acoustic wave device includes an interdigital transducer electrode connected to first and second terminals, and a reflector connected to the second terminal. In a group of electrode fingers of the interdigital transducer electrode, the electrode fingers at one end and another end in a second direction are respectively first and second end electrode fingers, the first end electrode finger includes a wide portion at a distal end portion. The first end electrode finger is located between the reflector and the second end electrode finger in the second direction. An inner busbar portion of one of first and second busbars not connected to the first end electrode finger, is located on an inner side in the second direction relative to the wide portion of the first end electrode finger so as not to overlap the wide portion of the first end electrode finger in a first direction.

A filter device includes a filter circuit including series-arm resonators and series-arm-resonator connecting wires, and an additional circuit including a resonator including first and second interdigital transducer electrodes, first and second capacitors connected between the first and second interdigital transducer electrodes and the filter circuit, and first and second I-C connecting wires connected to the first and second interdigital transducer electrodes and the first and second capacitors, the additional circuit being connected in parallel with a portion of the series-arm resonators in the filter circuit. The first and second interdigital transducer electrodes are output-side interdigital transducer electrodes. A capacitance of the first capacitor is smaller than the capacitance of the second capacitor. A shortest distance among distances between the first I-C connecting wire and the series-arm-resonator connecting wires is shortest among shortest distances between the I-C connecting wires and the series-arm-resonator connecting wires.

Aspects of this disclosure relate to an acoustic wave filter that includes a multi-mode surface acoustic wave filter and a ladder section. The multi-mode surface acoustic wave filter has a higher impedance at an output than at an input. The ladder section is connected to the output of the multi-mode surface acoustic wave filter. Related radio frequency systems, radio frequency modules, wireless communication devices, and methods are disclosed.

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 surface acoustic wave device can have a piezoelectric layer and at least one interdigital transducer electrode thereon with a trapezoidal shape. This can be useful to fill dead space or voids between nonparallel elements on the layer. For example, an array with ranks of slanted interdigital transducer electrodes may not be aligned with non-slanted elements (e.g., a surface acoustic wave filter). This can leave voids or openings with unused portions of the piezoelectric layer. Trapezoidal elements such as those described here can solve this problem and help suppress transverse modes.

An acoustic wave filter package is disclosed. The acoustic wave filter package can include a first acoustic wave filter, a second acoustic wave filter, and a shared node. The first acoustic wave filter is configured to filter a first radio frequency signal. The first acoustic wave filter has a first shunt resonator. The second acoustic wave filter is configured to filter a second radio frequency signal. The second acoustic wave filter having a second shunt resonator. The first and second shunt resonators are electrically coupled to ground at the shared node.

Interdigital transducer (IDT) and reflective structure arrangements for surface acoustic wave (SAW) devices are disclosed. Representative SAW devices are described herein with reduced overall size while maintaining good quality factors. In certain embodiments, a SAW device may include an IDT arranged between reflective structures on a piezoelectric material. The reflective structures may include reflective IDTs that are configured to have a phase difference with the IDT to reflect and confine acoustic waves in the piezoelectric material. In certain embodiments, the reflective structures may be electrically connected to at least one of an input signal or an output signal. In this manner, the reflective structures may be configured with reduced size as compared to conventional reflective structures such as gratings, thereby providing a SAW device with reduced dimensions without a negative impact on device performance.

An acoustic wave device includes a plurality of interdigital transducer electrodes, in a first interdigital transducer electrode, a first electrode finger includes a wide portion having a greater width in the second direction than a center portion. In the first interdigital transducer electrode, for the first electrode finger, a first distance that is a maximum distance in the second direction between a center line of the center portion in a first direction is shorter than a second distance that is a maximum distance in a second direction between the center line of the center portion and an outer edge, away from a second interdigital transducer electrode, of the wide portion.

Interdigital transducer (IDT) and reflective structure arrangements for surface acoustic wave (SAW) devices are disclosed. Representative SAW devices are described herein with reduced overall size while maintaining good quality factors. In certain embodiments, a SAW device may include an IDT arranged between reflective structures on a piezoelectric material. The reflective structures may include reflective IDTs that are configured to have a phase difference with the IDT to reflect and confine acoustic waves in the piezoelectric material. In certain embodiments, the reflective structures may be electrically connected to at least one of an input signal or an output signal. In this manner, the reflective structures may be configured with reduced size as compared to conventional reflective structures such as gratings, thereby providing a SAW device with reduced dimensions without a negative impact on device performance.

An acoustic wave device includes a piezoelectric body portion, an interdigital transducer electrode connected to a first terminal and a second terminal, and a reflector connected to the second terminal. In the interdigital transducer electrode, in the interdigital transducer electrode, where, of a group of electrode fingers, the electrode finger located at one end in a second direction is a first end electrode finger and the electrode finger located at another end is a second end electrode finger, the first end electrode finger is located between the reflector and the second end electrode finger in the second direction. An outer busbar portion of one of a first busbar and a second busbar, not connected to the first end electrode finger, is located on an inner side in the second direction relative to a center portion, in a first direction, of the first end electrode finger.