Abstract: A boundary acoustic waves device includes a piezoelectric substrate having piezoelectricity, interdigitated electrodes formed on the piezoelectric substrate, a first medium formed on the piezoelectric substrate so as to cover the interdigitated electrode, and a second medium formed on the first medium. The interdigitated electrodes include a plurality of electrode fingers and bus bars that connect ends of the plurality of electrode fingers. A third medium is formed on the first medium. The second medium and the third medium are in contact with the first medium. The first medium, the second medium, and the third medium are formed of different materials. The first medium, the second medium, and the third medium are different in a ratio in length of a part with the third medium formed with respect to a length of a propagation path of boundary acoustic waves in a cross-section perpendicular to a longitudinal direction of the electrode fingers, in the longitudinal direction of the electrode fingers.

Abstract: An acoustic wave device includes a piezoelectric substrate, interdigital electrodes arranged on the piezoelectric substrate, a first dielectric element arranged between the interdigital electrodes, a second dielectric element that covers the interdigital electrodes and the first dielectric element, and an adjustment element that has been formed on the first dielectric element. The adjustment element has been formed from a material whose specific gravity is greater than that of the first dielectric element and that of the second dielectric element.

Abstract: An acoustic wave element includes: resonators 2 each including an electrode to excite acoustic waves; a power supply wiring portion 3 that is disposed so as to connect the resonators 2 electrically; a piezoelectric substrate 4 on which the resonators 2 and the power supply wiring portion 3 are formed; a second medium 5 that is formed on the piezoelectric substrate 4 so as to cover the resonators 2; and a third medium 6 that is formed on the piezoelectric substrate 4 so as to cover at least the second medium 5 and the power supply wiring portion 3. A side surface 34 of the power supply wiring portion 3 that is in contact with a surface of the piezoelectric substrate 4 forms an obtuse first angle ? with respect to the surface 4a of the piezoelectric substrate 4.

Abstract: A configuration that reduces a parasitic capacitance between wires is achieved at a low cost. Disclosed is an acoustic wave filter provided with a piezoelectric substrate 1, resonators 2a and 2b that include a comb-shaped electrode formed on the piezoelectric substrate 1, a wiring portion 3 that is connected to the comb-shaped electrode, and a dielectric layer 4 formed to cover the comb-shaped electrode. The wiring portion 3 is provided with a lower layer wiring portion 3d that is disposed in the same layer as the comb-shaped electrode and an upper layer wiring portion 3e that is disposed on the lower layer wiring portion 3d. The upper layer wiring portion 3e includes a region that has a wider electrode width than the electrode width of the lower layer wiring portion 3d.

Abstract: An elastic wave device is described which includes a piezoelectric substrate, comb-shaped electrodes having teeth electrodes that are disposed so as to face each other on the piezoelectric substrate, a non-overlapping area in which the teeth electrodes of the comb-shaped electrodes do not overlap each other, and a overlapping area in which the teeth electrodes overlap each other and the velocity of sound is higher than that in the non-overlapping area.

Abstract: An elastic wave device includes resonators having a piezoelectric substrate, a resonation unit formed on the piezoelectric substrate, and reflectors formed on respective sides of the resonation unit on the piezoelectric substrate, and bumps formed on the piezoelectric substrate. The resonators are configured such that two or more split resonators are connected in parallel, and a bump is formed in a region sandwiched between reflectors of the split resonators.

Abstract: A boundary acoustic waves device includes a piezoelectric substrate (16) having piezoelectricity, interdigitated electrodes (14a, 14b) formed on the piezoelectric substrate, a first medium (17) formed on the piezoelectric substrate so as to cover the interdigitated electrode, and a second medium (18) formed on the first medium. The interdigitated electrodes include a plurality of electrode fingers (13a, 13b) and bus bars (12a, 12b) that connect ends of the plurality of electrode fingers. A third medium (19a) is formed on the first medium. The second medium and the third medium are in contact with the first medium. The first medium, the second medium, and the third medium are formed of different materials.

Abstract: An elastic boundary wave device of the present invention includes a plurality of elastic boundary wave elements. The elastic boundary wave elements each include a piezoelectric material layer, an electrode disposed over the piezoelectric material layer, a first dielectric layer formed over the piezoelectric material layer so as to cover the electrode, and a second dielectric layer formed over the first dielectric layer. An acoustic velocity of the second dielectric layers is faster than an acoustic velocity of the first dielectric layers, and the acoustic velocity of the second dielectric layer of at least one elastic boundary wave element from among the plurality of elastic boundary wave elements is different from the acoustic velocity of the second dielectric layer of another of the elastic boundary wave elements. This enables improving the degree of suppression in use as a filter in the elastic boundary wave device.

Abstract: An elastic boundary wave device includes a first medium with piezoelectricity, an electrode exciting an elastic wave and provided on the first medium, a second medium made of a different material from the first medium and provided on the first medium to cover the electrode, and a sound absorbing portion provided on the second medium.

Abstract: A method of producing an acoustic wave device includes: forming an interdigital electrode 3 on a piezoelectric substrate 2; forming a barrier film 4 so as to cover the interdigital electrode 3; forming a medium 5 on the barrier film 4; measuring a frequency characteristic of an acoustic wave excited by the interdigital electrode 3; and forming, in an excitation region, an adjustment region having a thickness different from other portions by patterning the barrier film 4 or further providing an adjustment film. When forming the adjustment region, an area T of the adjusting area is adjusted in accordance with the measured frequency characteristic.

Abstract: An acoustic wave device includes a piezoelectric substrate, interdigital electrodes arranged on the piezoelectric substrate, a first dielectric element arranged between the interdigital electrodes, a second dielectric element that covers the interdigital electrodes and the first dielectric element, and an adjustment element that has been formed on the first dielectric element. The adjustment element has been formed from a material whose specific gravity is greater than that of the first dielectric element and that of the second dielectric element.

Abstract: A first acoustic wave device includes a second acoustic wave device. The second acoustic wave device includes a substrate made of a piezoelectric material, a pair of interdigital electrodes formed on the substrate, each of the intergidital electrodes including a plurality of electrode fingers, and a adjustment medium. The adjustment medium includes at least a single layer and is formed on at least a part of the pair of the intergidital electrodes. The adjustment medium further includes a thick portion and a thin portion being null or thinner than the thick portion, an area of the thick portion opposed to a region being determined according to a predetermined characteristic value, the area including the intergital electrodes and a plurality of spaces between the electrode fingers adjacent each other.

Abstract: A filter includes a parallel resonator having first comb electrodes provided on a piezoelectric substrate and a first dielectric film that covers the first comb electrodes, and a series resonator having second comb electrodes provided on the piezoelectric substrate and a second dielectric film covers the second comb electrodes and is made of a material identical to that of the first dielectric film. The first dielectric film has a different thickness from that of the second dielectric film.

Abstract: An elastic wave device includes resonators having a piezoelectric substrate, a resonation unit formed on the piezoelectric substrate, and reflectors formed on respective sides of the resonation unit on the piezoelectric substrate, and bumps formed on the piezoelectric substrate. The resonators are configured such that two or more split resonators are connected in parallel, and a bump is formed in a region sandwiched between reflectors of the split resonators.

Abstract: An acoustic wave element includes: resonators 2 each including an electrode to excite acoustic waves; a power supply wiring portion 3 that is disposed so as to connect the resonators 2 electrically; a piezoelectric substrate 4 on which the resonators 2 and the power supply wiring portion 3 are formed; a second medium 5 that is formed on the piezoelectric substrate 4 so as to cover the resonators 2; and a third medium 6 that is formed on the piezoelectric substrate 4 so as to cover at least the second medium 5 and the power supply wiring portion 3. A side surface 34 of the power supply wiring portion 3 that is in contact with a surface of the piezoelectric substrate 4 forms an obtuse first angle ? with respect to the surface 4a of the piezoelectric substrate 4.

Abstract: An elastic boundary wave device of the present invention includes a plurality of elastic boundary wave elements. The elastic boundary wave elements each include a piezoelectric material layer, an electrode disposed over the piezoelectric material layer, a first dielectric layer formed over the piezoelectric material layer so as to cover the electrode, and a second dielectric layer formed over the first dielectric layer. An acoustic velocity of the second dielectric layers is faster than an acoustic velocity of the first dielectric layers, and the acoustic velocity of the second dielectric layer of at least one elastic boundary wave element from among the plurality of elastic boundary wave elements is different from the acoustic velocity of the second dielectric layer of another of the elastic boundary wave elements. This enables improving the degree of suppression in use as a filter in the elastic boundary wave device.

Abstract: In an acoustic wave filter, a notch resonator is connected in series (or parallel) with a plurality of acoustic wave resonators connected in a ladder shape. The notch resonator has a main resonant frequency that is substantially equal to a sub-resonant frequency of the acoustic wave resonators. With this configuration, the occurrence of sub-resonant responses in filter characteristics can be suppressed, resulting in an improvement in communication characteristics.

Abstract: An acoustic wave device includes a piezoelectric substrate, a resonator having comb electrodes that are provided above the piezoelectric substrate and excite an acoustic wave, and a capacitor that is provided above the piezoelectric substrate and is connected in series or parallel with the resonator, the capacitor including electrodes that horizontally face each other above the piezoelectric substrate. The electrodes of the capacitor are further from the piezoelectric substrate than the comb electrodes of the resonator.

Abstract: An acoustic wave device includes a piezoelectric substrate, a first dielectric film formed on the piezoelectric substrate, and electrodes that are provided on the first dielectric film and excite an acoustic wave, the electrodes including electrode fingers. At least a part of the first dielectric film is cut out between adjacent electrode fingers among the electrode fingers.

Abstract: An elastic wave device is described which includes a piezoelectric substrate, comb-shaped electrodes having teeth electrodes that are disposed so as to face each other on the piezoelectric substrate, a non-overlapping area in which the teeth electrodes of the comb-shaped electrodes do not overlap each other, and a overlapping area in which the teeth electrodes overlap each other and the velocity of sound is higher than that in the non-overlapping area.