An elastic wave includes a piezoelectric substrate having a polarization direction denoted by an arrow Px, and first and second IDT electrodes arranged on the substrate in an elastic wave propagation direction with a shared reflector therebetween. A first bus bar of the first IDT electrode and a first end portion bus bar of a second reflector are connected to a wiring electrode to define a first terminal. A second bus bar of the first IDT electrode and a second end portion bus bar of the shared reflector are connected to each other to define a second terminal. A first end portion bus bar and a first bus bar are electrically connected to each other. A second bus bar and a second end portion bus bar are electrically connected to each other, and the first and second IDT electrodes and are connected in parallel between the first and second terminals.

A filter device that reduces spurious emissions generated in a frequency band 1.2 to 1.4 times greater than a center frequency of a passband of a filter. In one example the filter device includes a first filter connected between a common contact and a first signal contact and having a first passband, and a second filter connected between the common contact and a second signal contact and having a second passband with a center frequency in a range of 1.2 to 1.4 times greater than a center frequency of the first passband. The first filter includes a SAW filter formed on a piezoelectric substrate, a SAW resonator formed on the piezoelectric substrate and connected in series between the common contact and the SAW filter, and a dielectric film covering the SAW filter and SAW resonator, the dielectric film having a reduced thickness in a region corresponding to the SAW resonator.

An acoustic wave device includes: a support substrate; a first piezoelectric substrate bonded to a first principal surface of the support substrate, the first piezoelectric substrate being a single crystal substrate, a first acoustic wave resonator located on an opposite surface of the first piezoelectric substrate from a surface to which the support substrate is bonded, the first acoustic wave resonator including an IDT; a second piezoelectric substrate bonded to a second principal surface of the support substrate opposite from the first principal surface, the second piezoelectric substrate being a single crystal substrate; and a second acoustic wave resonator located on an opposite surface of the second piezoelectric substrate from a surface to which the support substrate is bonded, the second acoustic wave resonator including an IDT.

An RF ladder filter having a parallel capacitance compensation circuit is disclosed. The parallel capacitance compensation circuit is made up of a first inductive element with a first T-terminal and a first end coupled to a first ladder terminal and a second inductive element with a second T-terminal that is coupled to the first T-terminal of the first inductive element and a second end coupled to a second ladder terminal. Further included is a compensating acoustic RF resonator (ARFR) having a fixed node terminal and a third T-terminal that is coupled to the first T-terminal of the first inductive element and the second T-terminal of the second inductive element, and a finite number of series-coupled ladder ARFRs, wherein the parallel capacitance compensation circuit is coupled across one of the finite number of series-coupled ARFRs by way of the first ladder terminal and the second ladder terminal.

An acoustic filter device for telecommunication devices includes a first acoustic band pass filter having a corresponding first passband and a second acoustic band pass filter having a corresponding second passband. The second acoustic band pass filter is connected in parallel with the first acoustic band pass filter to provide a combined passband including the first and second passbands.

An acoustic wave device comprises a substrate including a piezoelectric material, and interdigital transducer (IDT) electrodes disposed on a surface of the substrate. The IDT electrodes have gap regions, edge regions, and center regions. A maximum width of the IDT electrodes in the gap regions is greater than the maximum width of the IDT electrodes in the edge regions, thereby achieving a velocity of an acoustic wave in the gap regions being greater than the velocity of the acoustic wave in the center regions, and the velocity of the acoustic wave in the center regions being greater than the velocity of the acoustic wave in the edge regions.

A filter device includes a first path, a second path, and a capacitor. The first path includes at least one ladder filter circuit and connects a first terminal and a second terminal. The at least one ladder filter circuit includes a parallel arm resonator connected to a ground terminal. The second path includes a grounded resonator and is connected in parallel with any of the at least one ladder filter circuit. One end of the capacitor is connected to the second path, and the other end of the capacitor is connected to a third path which connects the parallel arm resonator and the ground terminal.

An acoustic wave device includes: a support substrate; a piezoelectric substrate bonded to the support substrate; a first acoustic wave element formed on the piezoelectric substrate; a frame formed on the support substrate to surround the first acoustic wave element; and a substrate formed on the frame so that a cavity to which the first acoustic wave element is exposed is formed above the piezoelectric substrate, wherein a difference in linear expansion coefficient between the support substrate and the substrate in a first direction in a surface direction of the piezoelectric substrate is less than a difference in linear expansion coefficient between the support substrate and the piezoelectric substrate in the first direction, and the piezoelectric substrate remains in a region where the first acoustic wave element is formed and is removed in a region where the frame is formed.

An acoustic wave filter includes a first input terminal and a first output terminal, and a longitudinally coupled resonator coupled between the first input terminal and the first output terminal. The longitudinally coupled resonator includes one or more input-side resonators coupled to the first input terminal and one or more output-side resonators coupled to the first output terminal. A total electrostatic capacitance of the one or more input-side resonators is less than a total electrostatic capacitance of the one or more output-side resonators.

An acoustic wave component is disclosed. The acoustic wave component can include a bulk acoustic wave resonator and a surface acoustic wave device. The bulk acoustic wave resonator can include a first portion of a ceramic substrate, a first piezoelectric layer positioned on the ceramic substrate, and electrodes positioned on opposing sides of the first piezoelectric layer. The surface acoustic wave device can include a second portion of the ceramic substrate, a second piezoelectric layer positioned on the ceramic substrate, and an interdigital transducer electrode on the second piezoelectric layer.