Murata Manufacturing Co., Ltd.

Tomohisa Komura

Michio Kadota

Takeshi Nakao

Masakazu Mimura

Junpei Yasuda

Norio Taniguchi

Kenichi Uesaka

Kentaro Funahashi

Shizuka Kawamura

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 C/r>C/rand r<rare satisfied.

Acoustic wave filter and multiplexer

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.

Multiplexer

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.

Elastic wave device

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.

Surface acoustic wave filter device

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 LiTaOsubstrates, and the cut angle of the first piezoelectric substrate is greater than the cut angle of the second piezoelectric substrate.

Growing community of inventors

Nagaokakyo, Japan

Tomohisa Komura