Abstract: A transmission elastic wave filter element and a reception elastic wave filter element each flip-chip mounted to a principal surface of a substrate are sealed off by a sealing member. The sealing member includes a base portion in contact with the principal surface of the substrate and made of a first dielectric material, and a lower dielectric-constant portion made of a second dielectric material having a dielectric constant lower than that of the first dielectric material and arranged in at least one of a region of the sealing member that faces the transmission elastic wave filter element on a side opposite from the substrate with respect to the transmission elastic wave filter element, and a region of the sealing member that faces the reception elastic wave filter element on the side opposite from the substrate with respect to the reception elastic wave filter element.

Abstract: In an elastic wave duplexer, a reception elastic wave filter element and a transmission elastic wave filter element are flip-chip mounted to a principal surface of a substrate. A sealing member is disposed on the principal surface of the substrate to cover and seal off at least one of the reception elastic wave filter element and the transmission elastic wave filter element. The sealing member has different thicknesses between a reception-element-covering region, which faces the reception elastic wave filter element on the side opposite from the substrate with respect to the reception elastic wave filter element, and a transmission-element-covering region, which faces the transmission elastic wave filter element on the side opposite from the substrate with respect to the transmission elastic wave filter element.

Abstract: A highly reliable surface acoustic wave device includes wiring lines that do not easily rupture at a three-dimensional wiring portion. The surface acoustic wave device includes a plurality of surface acoustic wave elements located on a piezoelectric substrate, a supporting member arranged on the piezoelectric substrate so as to enclose vibrating portions including electrodes such as IDT electrodes, and a cover member stacked so as to cover openings of the supporting member and to define hollow spaces facing vibrating electrodes. Furthermore, a three-dimensional wiring portion at which a first wiring line and a second wiring line are stacked with an insulating layer interposed therebetween is provided on the piezoelectric substrate. The three-dimensional wiring portion is enclosed by the supporting member, and thereby disposed inside a space enclosed by the piezoelectric substrate, the supporting member, and the cover member.

Abstract: In an elastic wave duplexer, a reception elastic wave filter element and a transmission elastic wave filter element are flip-chip mounted to a principal surface of a substrate. A sealing member is disposed on the principal surface of the substrate to cover and seal off at least one of the reception elastic wave filter element and the transmission elastic wave filter element. The sealing member has different thicknesses between a reception-element-covering region, which faces the reception elastic wave filter element on the side opposite from the substrate with respect to the reception elastic wave filter element, and a transmission-element-covering region, which faces the transmission elastic wave filter element on the side opposite from the substrate with respect to the transmission elastic wave filter element.

Abstract: A transmission elastic wave filter element and a reception elastic wave filter element each flip-chip mounted to a principal surface of a substrate are sealed off by a sealing member. The sealing member includes a base portion in contact with the principal surface of the substrate and made of a first dielectric material, and a lower dielectric-constant portion made of a second dielectric material having a dielectric constant lower than that of the first dielectric material and arranged in at least one of a region of the sealing member that faces the transmission elastic wave filter element on a side opposite from the substrate with respect to the transmission elastic wave filter element, and a region of the sealing member that faces the reception elastic wave filter element on the side opposite from the substrate with respect to the reception elastic wave filter element.

Abstract: A highly reliable surface acoustic wave device includes wiring lines that do not easily rupture at a three-dimensional wiring portion. The surface acoustic wave device includes a plurality of surface acoustic wave elements located on a piezoelectric substrate, a supporting member arranged on the piezoelectric substrate so as to enclose vibrating portions including electrodes such as IDT electrodes, and a cover member stacked so as to cover openings of the supporting member and to define hollow spaces facing vibrating electrodes. Furthermore, a three-dimensional wiring portion at which a first wiring line and a second wiring line are stacked with an insulating layer interposed therebetween is provided on the piezoelectric substrate. The three-dimensional wiring portion is enclosed by the supporting member, and thereby disposed inside a space enclosed by the piezoelectric substrate, the supporting member, and the cover member.

Abstract: A duplexer includes transmission-side and reception-side band filters respectively including a plurality of surface acoustic wave resonators connected together to define a ladder circuit. Each of the surface acoustic wave resonators includes a 47° to 58° rotated, Y-cut, X-propagating LiNbO3 substrate and an IDT electrode provided on the LiNbO3 substrate. The IDT electrode includes a Ti foundation electrode layer provided on the LiNbO3 substrate formed through epitaxial growth and an Al electrode layer formed through epitaxial growth on the Ti foundation electrode layer, and a (111) face of the Al electrode layer, a (001) face or (100) face of the Ti foundation electrode layer, and a (001) face of the LiNbO3 substrate are aligned in parallel.

Abstract: A surface acoustic wave demultiplexer includes a first surface acoustic wave filter, a second surface acoustic wave filter having a higher center frequency than the first surface acoustic wave filter, and a one-port surface acoustic wave resonator connected to an input terminal of the first surface acoustic wave filter in series and having an anti-resonant frequency in the stop band of the first surface acoustic wave filter. A first piezoelectric substrate that constitutes the first surface acoustic wave filter and a second piezoelectric substrate that constitutes the second surface acoustic wave filter are made from different piezoelectric materials.

Abstract: In a ladder type filter, a first inductor is connected in series with a parallel resonator. A second inductor is connected in parallel to a series resonator. The resonant point of the parallel resonator having the first inductor connected in series and the anti-resonant point of the series resonator developed on the lower frequency side of the resonant point of the series resonator, caused by the second inductor connected in parallel, substantially coincide with each other.

Abstract: A surface acoustic wave demultiplexer includes a first surface acoustic wave filter, a second surface acoustic wave filter having a higher center frequency than the first surface acoustic wave filter, and a one-port surface acoustic wave resonator connected to an input terminal of the first surface acoustic wave filter in series and having an anti-resonant frequency in the stop band of the first surface acoustic wave filter. A first piezoelectric substrate that constitutes the first surface acoustic wave filter and a second piezoelectric substrate that constitutes the second surface acoustic wave filter are made from different piezoelectric materials.

Abstract: In a ladder type filter, a first inductor is connected in series with a parallel resonator. A second inductor is connected in parallel to a series resonator. The resonant point of the parallel resonator having the first inductor connected in series and the anti-resonant point of the series resonator developed on the lower frequency side of the resonant point of the series resonator, caused by the second inductor connected in parallel, substantially coincide with each other.