Abstract: A SAW filter includes a piezoelectric body, an IDT electrode on the piezoelectric body, and signal wiring electrically connected to the IDT electrode. The signal wiring has a thickness not less than a skin depth specified based on the frequency of a signal passing through the signal wiring and the electrical conductivity of the signal wiring. As a result, the signal wiring has low propagation loss of the signal passing through it, so that the SAW filter has excellent transmission characteristics.

Abstract: An acoustic wave resonance device includes: piezoelectric substrate (1), first acoustic wave resonator (100) provided on an upper surface of piezoelectric substrate (1) and including first interdigital transducer electrode (110), and second acoustic wave resonator (200) provided on piezoelectric substrate (1) and including second interdigital transducer electrode (210). First acoustic wave resonator (100) and second acoustic wave resonator (200) are connected to each other. An overlap width of a plurality of first comb-shaped electrodes (112) forming first acoustic wave resonator (100) is larger than an overlap width of a plurality of second comb-shaped electrodes (212) forming second acoustic wave resonator (200). With such a configuration, frequencies in which a transverse mode spurious response is generated can be distributed and loss can be reduced.

Abstract: A surface acoustic wave device includes a substrate including lithium niobate; a IDT being provided on an upper surface of the substrate and including a plurality of electrode fingers; and a protective film covering the IDT and having an uneven shape on an upper surface thereof. When a pitch width of one pitch of the IDT is p, a width of one of the electrode fingers is p1, a width between the electrode fingers is p2, and a thickness of the IDT is h, following relations are satisfied, p1+p2=p, and h/(2×p)?4.5%. With this configuration, an appropriate reflection characteristic is realized, and the surface acoustic wave device having excellent temperature coefficient of frequency and electrical characteristic can be obtained.

Abstract: An acoustic boundary wave device includes a piezoelectric body, an IDT layer formed on the piezoelectric body, a pad electrode layer formed on the piezoelectric body and connected to the IDT layer, a first dielectric layer formed on the piezoelectric body and covering at least a part of the IDT electrode layer, and a second dielectric layer formed on the piezoelectric body, covering the first dielectric layer, and having an opening through which at least a part of a top face of the pad electrode layer is exposed. The metal forming lateral faces of the pad electrode layer diffuses more readily into the first dielectric layer than into the second dielectric layer. The second dielectric layer covers the lateral faces of the pad electrode layer and prevents the first dielectric layer from touching the lateral faces of the pad electrode layer.

Abstract: A surface acoustic wave resonator of the present invention includes a piezoelectric substrate (10), a first surface acoustic wave resonator (20) having a comb electrode (11) provided on the piezoelectric substrate (10), and a second surface acoustic wave resonator (30) having a comb electrode (12) provided on the piezoelectric substrate (10). The first surface acoustic wave resonator (20) and the second surface acoustic wave resonator (30) are apodized and connected in parallel.

Abstract: An elastic wave element includes a piezoelectric substrate, an interdigital electrode provided on the piezoelectric substrate, a silicon oxide film covering the interdigital electrode, and a silicon nitride oxide film provided on the silicon oxide film. A film thickness H of the silicon oxide film and a wave length ? of an elastic wave propagating through the piezoelectric substrate satisfies a relation of H/??0.15. The elastic wave element reduces fluctuation of propagation characteristics of elastic waves, and has high reliability.