Abstract: An acoustic wave filter includes at least one of a first series arm resonator circuit in a path connecting input/output terminals and a first parallel arm resonator circuit between a node in the path and ground. At least one of the first series arm resonator circuit and the first parallel arm resonator circuit includes a segmented resonator group including first and second acoustic wave resonators connected in series, an IDT electrode included in the first acoustic wave resonator includes a first withdrawal electrode, and C1/r1>C2/r2 and r1<r2 are satisfied.

Abstract: A multiplexer includes a first filter circuit including a pass band that is a first frequency band, a second filter circuit including a pass band that is a second frequency band, and an additional circuit. The first filter circuit includes a first terminal connected to a common terminal and a second terminal connected to a first input/output terminal. The second filter circuit includes a third terminal connected to the common terminal and a fourth terminal connected to a second input/output terminal. The additional circuit is connected to the fourth terminal and one of the first and second terminals and includes a series-arm circuit on a series-arm path connecting the fourth terminal to the one of the terminals and a parallel-arm circuit on a parallel-arm path connecting the series-arm path to the ground. The parallel-arm circuit includes only an inductor, a capacitor, or an LC parallel-arm resonant circuit in series with the parallel-arm path.

Abstract: A multiplexer includes a first filter circuit including a pass band that is a first frequency band, a second filter circuit including a pass band that is a second frequency band, and an additional circuit. The first filter circuit includes a first terminal connected to a common terminal and a second terminal connected to a first input/output terminal. The second filter circuit includes a third terminal connected to the common terminal and a fourth terminal connected to a second input/output terminal. The additional circuit is connected to the fourth terminal and one of the first and second terminals and includes a series-arm circuit on a series-arm path connecting the fourth terminal to the one of the terminals and a parallel-arm circuit on a parallel-arm path connecting the series-arm path to the ground. The parallel-arm circuit includes only an inductor, a capacitor, or an LC parallel-arm resonant circuit in series with the parallel-arm path.

Abstract: A surface acoustic wave filter includes first and second signal terminals and first and second IDT electrodes that are adjacent to or in a vicinity of each other in an x-axis direction and that each includes a pair of comb-shaped electrodes each including a busbar electrode extending in the x-axis direction and electrode fingers extending in a y-axis direction. One of the comb-shaped electrodes in each of the first and second IDT electrodes is electrically connected to the first and second signal terminals, respectively. The surface acoustic wave filter further includes a bridging capacitance including a pair of comb-shaped electrodes arranged in a region outside an overlap region of the electrode fingers. One of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the first IDT electrode. The other of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the second IDT electrode.

Abstract: A surface acoustic wave filter includes first and second signal terminals and first and second IDT electrodes that are adjacent to or in a vicinity of each other in an x-axis direction and that each includes a pair of comb-shaped electrodes each including a busbar electrode extending in the x-axis direction and electrode fingers extending in a y-axis direction. One of the comb-shaped electrodes in each of the first and second IDT electrodes is electrically connected to the first and second signal terminals, respectively. The surface acoustic wave filter further includes a bridging capacitance including a pair of comb-shaped electrodes arranged in a region outside an overlap region of the electrode fingers. One of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the first IDT electrode. The other of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the second IDT electrode.

Abstract: An IDT electrode defining any one of a plurality of surface acoustic wave resonators defining series arm resonators and parallel arm resonators, except for the IDT electrode having a smallest amount of heat generation per unit time when a signal flows between first and second signal terminals, does not face wiring electrodes.

Abstract: An IDT electrode defining any one of a plurality of surface acoustic wave resonators defining series arm resonators and parallel arm resonators, except for the IDT electrode having a smallest amount of heat generation per unit time when a signal flows between first and second signal terminals, does not face wiring electrodes.

Abstract: A reception filter includes a first and second longitudinally coupled resonator-type surface acoustic wave filter portions and a surface acoustic wave resonator. The first and second longitudinally coupled resonator-type surface acoustic wave filter portions each include at least three IDT electrodes. The surface acoustic wave resonator includes one IDT electrode connected to at least one of the at least three IDT electrodes. The reception filter is arranged such that a ratio of a capacitance of the surface acoustic wave resonator to a capacitance of each of the at least one of the at least three IDT electrodes included in the longitudinally coupled resonator-type surface acoustic wave filter portion, the at least one of the at least three IDT electrodes being electrically connected to the one IDT electrode of the surface acoustic wave resonator, is in the range of about 1.9 to about 2.5.

Abstract: A surface acoustic wave branching filter includes a first filter and a second filter each including a plurality of surface acoustic wave resonators arranged in a ladder circuit configuration. The first filter in which the frequency range of the passband is relatively low is provided on a first piezoelectric substrate, and the second filter in which the frequency range of the passband is relatively high is provided on a second piezoelectric substrate. The first piezoelectric substrate and the second piezoelectric substrate are rotation Y-cut X-propagation LiTaO3 substrates, and the cut angle of the first piezoelectric substrate is greater than the cut angle of the second piezoelectric substrate.

Abstract: A surface acoustic wave branching filter includes a first filter and a second filter each including a plurality of surface acoustic wave resonators arranged in a ladder circuit configuration. The first filter in which the frequency range of the passband is relatively low is provided on a first piezoelectric substrate, and the second filter in which the frequency range of the passband is relatively high is provided on a second piezoelectric substrate. The first piezoelectric substrate and the second piezoelectric substrate are rotation Y-cut X-propagation LiTaO3 substrates, and the cut angle of the first piezoelectric substrate is greater than the cut angle of the second piezoelectric substrate.

Abstract: A one-port surface acoustic wave resonator includes a rotated Y-cut LiTaO3 substrate, an interdigital electrode transducer disposed on the LiTaO3 substrate, and reflectors disposed on both sides of the interdigital electrode transducer in the surface acoustic wave propagation direction of the interdigital electrode transducer. When the electrode finger width of the interdigital electrode transducer is denoted by a and the gap between the electrode fingers is denoted by b, the metallization ratio, a/(a+b), is in the range of about 0.55 to about 0.85 and the interdigital electrode transducer is overlapping-length weighted.