Murata Manufacturing Co., Ltd.

Keiji Okada

Hideki Iwamoto

Yuichi Takamine

Hajime Kando

Syunsuke Kido

Tsutomu Takai

Takashi Yamane

Munehisa Watanabe

Akira Michigami

Korekiyo Ito

Noriyoshi Ota

Masanori Otagawa

Ippei Hatsuda

An acoustic wave filter includes an input end, an output end, and a series arm connecting the input end and the output end. The series arm includes n (n=3) acoustic wave resonators connected in series in an order of first, second, and third acoustic wave resonators. The first, second, and third acoustic wave resonators include multiple electrode fingers. The first, second, and third acoustic wave resonators include an mth acoustic wave resonator (m is a natural number of 1<m<n, where m=2). An electrode finger pitch of the second acoustic wave resonator is smallest among electrode finger pitches of the first, second, and third acoustic wave resonators.

Acoustic wave filter and composite filter device

An acoustic wave filter includes at least three segmented resonator devices connected in series to one another and aligned in a direction that crosses an acoustic wave propagation direction and each including an InterDigital Transducer (IDT) electrode, and centers of respective IDT electrodes of an adjacent pair of the at least three segmented resonator devices in the acoustic wave propagation direction are not aligned when seen from a direction orthogonal to the acoustic wave propagation direction.

Acoustic wave filter

An acoustic wave resonator includes an IDT electrode that is on or above a piezoelectric plate and includes a periodic withdrawal weighted portion in each of a plurality of regions for at least two or more periods in an acoustic wave propagation direction. A periodic withdrawal weighted portion in at least one of the regions is different from a periodic withdrawal weighted portion in at least one of the other regions.

Acoustic wave resonator and multiplexer

A multiplexer includes a transmit filter circuit, a receive filter circuit, and an additional circuit connected in parallel with a portion of the transmit filter circuit. The transmit filter circuit includes series resonators on a signal path connecting a common terminal and a first terminal, and parallel resonators on the signal path between a node and ground. The series resonator closest to the first terminal includes split resonators. The additional circuit includes a capacitor and a resonator group. The resonator group includes IDT electrodes side by side in the direction of acoustic wave propagation. A first end of the resonator group is connected to the common terminal with the capacitor interposed therebetween. A second end of the resonator group is connected to the signal path between two of the split resonators such that no capacitor is interposed between the second end and the signal path.

Multiplexer

A filter device includes a longitudinally coupled resonator elastic wave filter that includes IDT electrodes including low acoustic velocity regions in outer side portions of center regions of the IDT electrodes and high acoustic velocity regions in outer side portions of the low acoustic velocity regions in a direction orthogonal or substantially orthogonal to an elastic wave propagation direction, and defines and functions as a first bandpass filter, and elastic wave resonators that are electrically connected to the longitudinally coupled resonator elastic wave filter.

Filter device including longitudinally coupled resonator elastic wave filter and elastic wave resonator

An elastic wave device includes IDT electrodes stacked on a piezoelectric thin film. The IDT electrode includes a plurality of first electrode fingers and a plurality of second electrode fingers. A line connecting the distal ends of the first electrode fingers or the distal ends of the second electrode fingers extends obliquely with respect to a propagation direction of an elastic wave at an oblique angle &#x3bd;. The oblique angle &#x3bd; is about 0.4&#xb0; or more and about 10&#xb0; or less.

Elastic wave device and filter device

An elastic wave device includes a low acoustic velocity film, a piezoelectric film, and an IDT electrode, which are laminated on a high acoustic velocity material. In the IDT electrode, first electrode fingers, or second electrode fingers, or each of the first electrode fingers and the second electrode fingers, includes a wide width portion with a dimension in a width direction larger than a dimension at a center in a length direction and being provided closer to at least one of a side of a proximal end and a side of a distal end than a central region, at least one of a first busbar and a second busbar includes cavities arranged in a busbar length direction, and at least one of the first busbar and the second busbar includes an inner busbar portion which is positioned closer to a side of the first electrode fingers or a side of the second electrode fingers than the cavities are and which extends in the length direction of the first busbar and the second busbar, a central busbar portion that includes the cavities, and an outer busbar portion.

Elastic wave device

An elastic wave device includes a support layer with a through-hole or a recess opened at an upper surface thereof, a piezoelectric thin film arranged on the support layer to extend above the recess or the through-hole of the support layer, and an IDT electrode defined on at least one of upper and lower surfaces of the piezoelectric thin film in a region of the piezoelectric thin film, the region extending above the recess, or the through-hole. A secondary mode of a plate wave, which contains a U1 component as a main component, is utilized. The piezoelectric thin film is made of LiTaO, and Euler angles (&#x3c6;, &#x3b8;, &#x3c8;) of the LiTaOfall within specific ranges.

Elastic wave device and manufacturing method for same

In a surface acoustic wave device, a plurality of surface acoustic wave elements include piezoelectric bodies having the same cut-angle. A propagation azimuth of a surface acoustic wave in at least one of surface acoustic wave elements is different from a propagation azimuth of a surface acoustic wave in at least another one of the surface acoustic wave elements. In each of the surface acoustic wave elements, a confinement layer configured to confine the surface acoustic wave inside the piezoelectric body is disposed on the piezoelectric body at the side opposite to the side where an electrode is located.

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Nagaokakyo, Japan

Keiji Okada