Kyocera Corporation

Takehiro Okumichi

Hiroyuki Tanaka

Yuji Kishida

Daisuke Yamamoto

A SAW element includes a piezoelectric substrate, a support substrate attached to a bottom surface of the piezoelectric substrate, and an IDT electrode on a top surface of the piezoelectric substrate. A resonance frequency and an anti-resonance frequency of a resonator including the IDT electrode are kept between a frequency of a lowest frequency bulk wave spurious and a frequency of a next lowest frequency bulk wave spurious.

Surface acoustic wave element

A filter includes a first signal line connected to one input-side unbalanced signal terminal, a second signal line connected to another output-side unbalanced signal terminal, a shunt circuit for providing connection between the first and second signal lines in parallel with a surface acoustic wave device, a first capacitor disposed in the first signal line so as to be in series with respect to the surface acoustic wave device, a first inductor disposed in the shunt circuit at a side of the first signal line, and a series resonance circuit having a second capacitor and a second inductor disposed in the shunt circuit at a side of the second signal line.

Filter and communications apparatus

Among the plurality of IDT electrodes having serially divided type structures, when designating any three continuously and sequentially arranged IDT electrodes as first, second, and third IDT electrodes in the order of arrangement, electrode fingers are arranged so that a first electrode finger pitch Pat the boundary between the first IDT electrode and the second IDT electrode in the first region and a second electrode finger pitch Pat the boundary between the second IDT electrode and the third IDT electrode in the first region are equal, the first and second electrode finger pitches Pand Pare the smallest among electrode finger pitches of IDT electrodes in the first region, and each of the IDT electrodes has a third electrode finger pitch Plarger than the first and second electrode finger pitches Pand Pin the first region.

Surface acoustic wave device with IDT electrodes having different electrode finger pitches and communication apparatus using same

An SAW device includes: a piezoelectric substrate; a first and a second SAW elementshaving three or more odd-number IDT electrodes-and reflector electrodes-arranged on the piezoelectric substrate; lineswhich cascade-connect the first and the second SAW elements; a first unbalanced signal terminalconnected to the IDT electrodesarranged at the both ends of the first SAW elements; and a second unbalanced signal terminalconnected to the IDT electrodesarranged at the both ends of the second SAW element. In each of the first and the second SAW elements, one bus bar electrodeof each of center IDT electrodesis split into two, and non-split bus bar electrodesof at least one center IDT electrode of the first and the second SAW elementsare connected to a reference potential electrode and the linesare made to be balanced signal lines.

Surface acoustic wave device and communication device

Signal wiring conductors are provided at opposing positions on the upper surface of the uppermost dielectric layer and on the lower surface of the bottommost dielectric layer, and grounding conductors surrounding grounding-conductor non-forming areas are provided on the upper surfaces of intermediate dielectric layers and the bottommost dielectric layer. These grounding conductors form an electromagnetically shielded space by being connected by grounding-conductor via conductors vertically penetrating the respective dielectric layers around the grounding-conductor non-forming areas, and signal via conductors are so provided in the respective dielectric layers as to penetrate this electromagnetically shielded space. A signal via conductor of the uppermost dielectric layer is connected with the signal wiring conductor on the upper surface thereof via a signal-wiring connecting conductor, and a signal via conductor of the bottommost dielectric layer is connected with the signal wiring conductor on the lower surface thereof via a signal-wiring connecting conductor.

High-frequency signal transmitting device

A high frequency wave measurement substrate comprising a dielectric substrate, a ground conductor being formed almost all over a bottom surface of the dielectric substrate, a microstrip line signal conductor and an radial stub-like equivalent ground conductor which is placed in proximity to an end of the microstrip line signal conductor being formed on a top surface of the dielectric substrate, a coplanar line structure wafer probe signal conductor and a ground conductor being electrically connected to both the signal conductor and the equivalent ground conductor, wherein the equivalent ground conductor is composed of a semi-circular or fan-shaped radial stub-like conductor pattern in which non-conductor areas are formed in its radial direction. The equivalent ground conductor is also composed of a plurality of radial conductors which are sharing a center with each other, disposed like an arc, and different from each other in length in the radial direction, and a connecting conductor for electrically connecting the radial conductors to each other electrically. In the high-frequency wave measurement substrate a product of a thickness h of the substrate and a square root of a relative dielectric constant &egr;,of the substrate is set to be,or more and,or less of a vacuum wavelength &lgr;,of a measurement upper limit frequency. Consequently, the standing charge density distribution in the circumferential direction is caused by lower frequencies, so that the low loss transmission frequency band can be expanded.

Growing community of inventors

Kyoto, Japan

Takehiro Okumichi