Abstract: A surface acoustic wave device includes a ZnO dielectric thin film on a quartz substrate and an IDT electrode having strips between the ZnO thin film and the quartz substrate. The IDT electrode has at least one region where the strips are disposed at an interval defined by approximately a half-wavelength of the surface acoustic wave. The duty ratio of the IDT electrode is preferably more than about 0.5. Alternatively, a protrusion is formed via a slope in the region of the ZnO thin film where the IDT electrode is disposed, and the inclination angle ? of the slope is more than about 30°.

Abstract: A boundary acoustic wave device includes a LiNbO3 substrate defining a first medium layer having a relatively high sound velocity and a SiO2 film defining a second medium layer having a relatively low sound velocity, an electroacoustic transducer and reflectors disposed between the first medium layer and the second medium layer, and recess portions and/or protrusion portions provided in the upper surface of the SiO2 film.

Abstract: A boundary acoustic wave device using SH boundary acoustic waves includes a first medium layer, a second medium layer stacked on the first medium layer, and an electrode including an interdigital electrode and reflectors. A sound absorbing layer is provided on the surface of the first medium layer and/or the second medium layer opposite the interface therebetween.

Abstract: A boundary acoustic wave device includes a dielectric substance that is laminated on one surface of a piezoelectric substance, an IDT and reflectors used as electrodes are disposed at a boundary between the piezoelectric substance and the dielectric substance, and the thicknesses of the electrodes are set such that the acoustic velocity of the SH type boundary acoustic wave is less than that of a slow transverse wave propagating in the dielectric substance and than that of a slow transverse wave propagating in the piezoelectric substance, so that a boundary acoustic wave device is formed.

Abstract: A surface acoustic wave device using second leaky surface acoustic waves the dominant component of which is a longitudinal wave component includes a LiTaO3 substrate and a conductive film formed on the LiTaO3 substrate. The density ? of the conductive film is in the range of about 2,699 kg/m3 to about 19,300 kg/m3.

Abstract: A surface acoustic wave device includes an asymmetrical double electrode which prevents a mismatch between reflected waves and propagating surface acoustic waves on strips, and which is capable of realizing a superior unidirectionality. This surface acoustic wave device includes the asymmetrical double electrode in which a half wavelength section includes first and second strips which have mutually different widths. The half wavelength is arranged to define a basic section. The surface acoustic wave device includes at least two of these basic sections disposed on a piezoelectric substrate. The absolute value of the vector angle of the reflection center is within approximately 45±10° or within approximately 135±10°, when the center of the basic section is the reference position. Alternatively, the absolute value of the phase difference between the excitation center and the reflection center is within approximately 45±10° or approximately 135±10°.

Abstract: A surface acoustic wave device includes a ZnO dielectric thin film on a quartz substrate and an IDT electrode having strips between the ZnO thin film and the quartz substrate. The IDT electrode has at least one region where the strips are disposed at an interval defined by approximately a half-wavelength of the surface acoustic wave. The duty ratio of the IDT electrode is preferably more than about 0.5. Alternatively, a protrusion is formed via a slope in the region of the ZnO thin film where the IDT electrode is disposed, and the inclination angle ? of the slope is more than about 30°.

Abstract: A surface acoustic wave device includes a ZnO dielectric thin film on a quartz substrate and an IDT electrode having strips between the ZnO thin film and the quartz substrate. The IDT electrode has at least one region where the strips are disposed at an interval defined by approximately a half-wavelength of the surface acoustic wave. The duty ratio of the IDT electrode is preferably more than about 0.5. Alternatively, a protrusion is formed via a slope in the region of the ZnO thin film where the IDT electrode is disposed, and the inclination angle ? of the slope is more than about 30°.

Abstract: A surface acoustic wave device includes an asymmetrical double electrode which prevents a mismatch between reflected waves and propagating surface acoustic waves on strips, and which is capable of realizing a superior unidirectionality. This surface acoustic wave device includes the asymmetrical double electrode in which a half wavelength section includes first and second strips which have mutually different widths. The half wavelength is arranged to define a basic section. The surface acoustic wave device includes at least two of these basic sections disposed on a piezoelectric substrate. The absolute value of the vector angle of the reflection center is within approximately 45±10° or within approximately 135±10°, when the center of the-basic section is the reference position. Alternatively, the absolute value of the phase difference between the excitation center and the reflection center is within approximately 45±10° or approximately 135±10°.

Abstract: A surface acoustic wave device includes an asymmetrical double electrode which prevents a mismatch between reflected waves and propagating surface acoustic waves on strips, and which is capable of realizing a superior unidirectionality. This surface acoustic wave device includes the asymmetrical double electrode in which a half wavelength section includes first and second strips which have mutually different widths. The half wavelength is arranged to define a basic section. The surface acoustic wave device includes at least two of these basic sections disposed on a piezoelectric substrate. The absolute value of the vector angle of the reflection center is within approximately 45±10° or within approximately 135±10°, when the center of the basic section is the reference position. Alternatively, the absolute value of the phase difference between the excitation center and the reflection center is within approximately 45±10° or approximately 135±10°.

Abstract: A boundary acoustic wave device includes a first boundary acoustic wave element, and a second boundary acoustic wave element disposed on the first boundary acoustic wave element. Each boundary acoustic wave element includes a first solid layer made of a piezoelectric material, a second solid layer made of one of a piezoelectric material and an insulating material, and disposed on the first solid layer, and a boundary acoustic wave exciting interdigital transducer arranged in the boundary between the first and second solid layers.

Abstract: A surface acoustic wave device includes an asymmetrical double electrode which prevents a mismatch between reflected waves and propagating surface acoustic waves on strips, and which is capable of realizing a superior unidirectionality. This surface acoustic wave device includes the asymmetrical double electrode in which a half wavelength section includes first and second strips which have mutually different widths. The half wavelength is arranged to define a basic section. The surface acoustic wave device includes at least two of these basic sections disposed on a piezoelectric substrate. The absolute value of the vector angle of the reflection center is within approximately 45±10° or within approximately 135±10°, when the center of the basic section is the reference position. Alternatively, the absolute value of the phase difference between the excitation center and the reflection center is within approximately 45±10° or approximately 135±10°.

Abstract: A surface acoustic wave device using second leaky surface acoustic waves the dominant component of which is a longitudinal wave component includes a LiTaO3 substrate and a conductive film formed on the LiTaO3 substrate. The density &rgr; of the conductive film is in the range of about 2,699 kg/m3 to about 19,300 kg/m3.

Abstract: A surface acoustic wave device includes a piezoelectric thin film arranged on a quartz substrate, and the quartz substrate has Euler angles (&phgr;, &thgr;, &psgr;) which satisfy −19°<&phgr;<+15°, 107°<&thgr;<125° and −10°<&psgr;<15°. A piezoelectric thin film is disposed on the quartz substrate, and comb electrodes are arranged so as to contact the piezoelectric thin film, wherein the normalized thickness H/&lgr; of the piezoelectric thin film is at least about 0.05 where the thickness of the piezoelectric thin film is H, and the wavelength of the surface acoustic wave is &lgr;.

Abstract: A surface acoustic wave device includes a LiNbO3 substrate with a Euler angle in an area defined by a rectangle having four comers with coordinates (1) (0°, 7°, 101°), (2) (0°, 23°, 79°), (3) (0°, 23°, 79°), and (4) (0°, 7°, 79°), for example, and an electrode film made of Au, wherein surface acoustic waves including a longitudinal wave component as a main component are propagated thereon. The surface acoustic wave device uses longitudinal surface acoustic waves having a phase speed greater than with the “slow transverse wave”, and has a great electromechanical coupling coefficient and small propagation loss, and is suitable for handling high-frequency signals.

Abstract: A surface acoustic wave device includes a piezoelectric thin film arranged on a quartz substrate, and the quartz substrate has Euler angles (&phgr;, &thgr;, &psgr;) which satisfy −19°<&phgr;<+15°, 107°<&thgr;<125° and −10°<&psgr;<15°. A piezoelectric thin film is disposed on the quartz substrate, and comb electrodes are arranged so as to contact the piezoelectric thin film, wherein the normalized thickness H/&lgr; of the piezoelectric thin film is at least about 0.05 where the thickness of the piezoelectric thin film is H, and the wavelength of the surface acoustic wave is &lgr;.

Abstract: A surface acoustic wave device includes a ZnO dielectric thin film on a quartz substrate and an IDT electrode having strips between the ZnO thin film and the quartz substrate. The IDT electrode has at least one region where the strips are disposed at an interval defined by approximately a half-wavelength of the surface acoustic wave. The duty ratio of the IDT electrode is preferably more than about 0.5. Alternatively, a protrusion is formed via a slope in the region of the ZnO thin film where the IDT electrode is disposed, and the inclination angle &thgr; of the slope is more than about 30°.

Abstract: A surface acoustic wave device includes an asymmetrical double electrode which prevents a mismatch between reflected waves and propagating surface acoustic waves on strips, and which is capable of realizing a superior unidirectionality. This surface acoustic wave device includes the asymmetrical double electrode in which a half wavelength section includes first and second strips which have mutually different widths. The half wavelength is arranged to define a basic section. The surface acoustic wave device includes at least two of these basic sections disposed on a piezoelectric substrate. The absolute value of the vector angle of the reflection center is within approximately 45±10° or within approximately 135±10°, when the center of the basic section is the reference position. Alternatively, the absolute value of the phase difference between the excitation center and the reflection center is within approximately 45±10° or approximately 135±10°.