Abstract: The present invention provides a dust core including, as principal components, a pulverized powder of an Fe-based amorphous alloy ribbon; and a Cr-containing Fe-based amorphous alloy atomized spherical powder, and the pulverized powder is in the shape of a thin plate having two principal planes opposing each other, and assuming that a minimum dimension along a plane direction of the principal planes is a grain size, the pulverized powder includes a pulverized powder with a grain size more than twice and not more than six times as large as a thickness of the pulverized powder in a proportion of 80 mass % or more of the whole pulverized powder and includes a pulverized powder with a grain size not more than twice as large as the thickness of the pulverized powder in a portion of 20 mass % or less of the whole pulverized powder.

Abstract: A boundary acoustic wave device includes a first medium layer made of piezoelectric material, a second medium layer provided on the first medium layer, a third medium layer provided on the second medium layer, and an electrode provided at an interface between the second and third medium layers. The electrode drives the third medium layer to generate a transverse wave. A propagation speed of the transverse wave in the third medium layer is lower than a propagation speed of the transverse wave in the first medium layer. A propagation speed of the transverse wave in the second medium layer is lower than the propagation speed of the transverse wave in the first medium layer. This boundary acoustic wave device has a large electro-mechanical coupling coefficient.

Abstract: A surface acoustic wave device includes a base substrate, first and second surface acoustic wave filters mounted on a surface of the base substrate, and a sealer provided on the surface of the base substrate and covering the first and second surface acoustic wave filters. The first and second surface acoustic wave filters include first and second piezoelectric substrates. The second piezoelectric substrate is located away from the first piezoelectric substrate via a gap. This surface acoustic wave device reduces inter-modulation.

Abstract: A surface acoustic wave resonator has a piezoelectric substrate (11), an IDT (13) formed of a plurality of electrode fingers (12) disposed on piezoelectric substrate (11), and reflectors (14) disposed near the opposite ends of IDT (13). The IDT (13) has a gradation region where the electrode finger pitch of the plurality of electrode fingers (12) at the opposite ends is different from the electrode finger pitch near the center of the IDT (13). In this gradation region, the electrode finger pitches are sequentially varied in the range from the electrode finger at the farthest end that is one end of the gradation region to the electrode finger lying at the other end of the gradation region. The electrode finger pitch of the electrode fingers at the farthest end that is one end of the gradation region is set to be 1 through 5% smaller than the electrode finger pitch near the center of the IDT (13).

Abstract: A surface acoustic wave resonator has piezoelectric substrate (11), IDT (13) formed of a plurality of electrode fingers (12) disposed on piezoelectric substrate (11), and reflectors (14) disposed near the opposite ends of IDT (13). IDT (13) has a gradation region where the electrode finger pitch of the plurality of electrode fingers (12) at the opposite ends is different from the electrode finger pitch near the center of IDT (13). In this gradation region, the electrode finger pitches are sequentially varied in the range from the electrode finger at the farthest end that is one end of the gradation region to the electrode finger lying at the other end of the gradation region. The electrode finger pitch of the electrode fingers at the farthest end that is one end of the gradation region is set to be 1 through 5% smaller than the electrode finger pitch near the center of IDT (13).

Abstract: A surface acoustic wave device includes a base substrate, first and surface acoustic wave filters mounted on a surface of the base substrate, and a sealer provided on the surface of the base substrate and covering the first and second surface acoustic wave filters. The first and second surface acoustic wave filters include first and second piezoelectric substrates. The second piezoelectric substrate is located away from the first piezoelectric substrate via a gap. This surface acoustic wave device reduces inter-modulation.

Abstract: A SAW filter is configured by forming a first IDT and a second IDT on a piezoelectric substrate, and the first IDT is arranged between one terminal of input/output terminals and another terminal of the input/output terminals, i.e., serially in a signal path, and the second IDT is arranged in parallel to a signal path from a portion between one terminal of the input/output terminals and the first IDT. The first IDT and the second IDT are arranged in proximity to each other and on the same propagation path of surface acoustic waves which are excited by each of the resonators.

Abstract: It is configured by forming first IDT (202) and second IDT (203) on piezoelectric substrate (201), and first IDT (202) is arranged between one terminal (204) of input/output terminals and other terminal (205) of the input/output terminals, i.e., serially to a signal path, and second IDT (203) is arranged in parallel to a signal path from a portion between one terminal (204) of the input/output terminals and first IDT (202). First IDT (202) and second IDT (203) are arranged in proximity to each other on the same propagation path of surface acoustic waves which are excited by respective resonators.

Abstract: A SAW resonator includes an IDT electrode formed on a piezoelectric substrate and reflector electrodes disposed on both sides of the IDT electrode. The IDT electrode includes first finger-electrodes, second finger-electrodes and strip-line electrodes. The first and the second finger-electrodes do not overlap with each other but are acoustically coupled together by the strip-line electrodes. This acoustic coupling by the strip-line electrodes eliminates the need for a common bus-bar electrode, so that the loss caused by the resistance of the common bus-bar electrode can be reduced, and the SAW resonator can be downsized.

Abstract: A SAW resonator includes an IDT electrode formed on a piezoelectric substrate and reflector electrodes disposed on both sides of the IDT electrode. The IDT electrode includes first finger-electrodes, second finger-electrodes and strip-line electrodes. The first and the second finger-electrodes do not overlap with each other but are acoustically coupled together by the strip-line electrodes. This acoustic coupling by the strip-line electrodes eliminates the need for a common bus-bar electrode, so that the loss caused by the resistance of the common bus-bar electrode can be reduced, and the SAW resonator can be downsized.

Abstract: A surface acoustic wave (SAW) device includes a comb-shaped electrode 2, a reflector 3 and a plurality of auxiliary electrodes 6a and 6b for surrounding the comb-shaped electrode 2 and the reflector 3, which are electrically independent of each other and have different widths locally. The SAW device is capable of efficiently and electrically uniformizing electric charge generated by pyroelectric property of a piezoelectric substrate 1.

Abstract: A SAW resonator includes an IDT electrode formed on a piezoelectric substrate and reflector electrodes disposed on both sides of the IDT electrode. The IDT electrode includes first finger-electrodes, second finger-electrodes and strip-line electrodes. The first and the second finger-electrodes do not overlap with each other but are acoustically coupled together by the strip-line electrodes. This acoustic coupling by the strip-line electrodes eliminates the need for a common bus-bar electrode, so that the loss caused by the resistance of the common bus-bar electrode can be reduced, and the SAW resonator can be downsized.

Abstract: A surface acoustic wave (SAW) device includes a piezoelectric substrate, and on this substrate there are provided comb electrodes for forming an inter digital transducer (IDT), reflector electrodes placed closely along a traveling direction of a surface wave generated by the IDT, and a frame-like short-circuited auxiliary electrode having a width varying depending on its portions. This structure allows to uniform electric charges overall the electrode-surfaces, where the electric charges are generated in a heat treatment applied to the piezoelectric substrate during the manufacturing of the SAW device. Thus even after the device is diced into pieces, this structure can prevent damages of the electrodes or degradation in electrical properties due to an electric discharge generated by accumulated electric charges caused by pyroelectricity of the substrate.

Abstract: A surface acoustic wave device comprises: a plurality of surface acoustic wave elements provided on a piezoelectric substrate to be electrically isolated with each other, a substrate provided with a first conductor electrically connecting the plurality of surface acoustic wave elements, a second conductor electrically isolated to the first conductor and an external terminal, and a sealing member for protecting the substrate and the piezoelectric substrate. For the substrate, a package having a recess or an insulating substrate is used. The first conductor is electrically isolated to the external terminal, while the second conductor is electrically connected with the external terminal. The above-described structure provides a small-sized surface acoustic wave device with excellent-attenuation characteristics.

Abstract: An interdigital transducer has one-wavelength basic units of a single phase unidirectional transducer a plurality of each having three electrode fingers within one wavelength; and a plurality of one-wavelength basic units of a bidirectional electrode each having four electrode fingers within the one wavelength, wherein the one-wavelength basic units are properly arranged according to a desired filter characteristic, and one of the three electrode fingers of each one-wavelength basic unit of the single phase unidirectional transducer is wider than the two other electrode fingers, and of the four electrode fingers of each one-wavelength basic unit of the bidirectional electrode, one pair of two fingers is interdigitated to the other pair of two fingers, and an adjustment section is provided between the one-wavelength basic units of the single phase unidirectional transducer and the one-wavelength basic units of the bidirectional electrode.

Abstract: A surface acoustic wave filter has a piezoelectric substrate; at least an input IDT electrode arranged on the piezoelectric substrate; and at least an output IDT electrode arranged on the plezoelectric substrate. A pitch of electrode fingers of the input IDT electrode and a pitch of electrode fingers of the output IDT electrode are different from each other.

Abstract: An interdigital transducer has

Abstract: A SAW resonator includes an IDT electrode formed on a piezoelectric substrate and reflector electrodes disposed on both sides of the IDT electrode. The IDT electrode includes first finger-electrodes, second finger-electrodes and strip-line electrodes. The first and the second finger-electrodes do not overlap with each other but are acoustically coupled together by the strip-line electrodes. This acoustic coupling by the strip-line electrodes eliminates the need for a common bus-bar electrode, so that the loss caused by the resistance of the common bus-bar electrode can be reduced, and the SAW resonator can be downsized.

Abstract: An interdigital transducer has one-wavelength basic units of a single phase unidirectional transducer a plurality of each having three electrode fingers within one wavelength; and a plurality of one-wavelength basic units of a bidirectional electrode each having four electrode fingers within the one wavelength, wherein the one-wavelength basic units are properly arranged according to a desired filter characteristic, and one of the three electrode fingers of each one-wavelength basic unit of the single phase unidirectional transducer is wider than the two other electrode fingers, and of the four electrode fingers of each one-wavelength basic unit of the bidirectional electrode, one pair of two fingers is interdigitated to the other pair of two fingers, and an adjustment section is provided between the one-wavelength basic units of the single phase unidirectional transducer and the one-wavelength basic units of the bidirectional electrode.

Abstract: An inter-digital transducer has a piezoelectric substrate; and an IDT (inter-digital transducer) electrode having a pair of upper bus bar electrode and lower bus bar electrode placed facing each other on the piezoelectric substrate and a plurality of electrode fingers placed on the piezoelectric substrate each being led out from either the upper bus bar electrode or the lower bus bar electrode toward the other bus bar electrode, wherein the IDT electrode is constructed of a plurality of divisional IDT electrodes and connected to a balanced type terminal.