In an elastic wave filter apparatus, IDT electrodes and first and second electrode lands are provided on a first main surface of a piezoelectric substrate. The piezoelectric substrate, a supporting layer, and a covering member define a hollow portion. A signal terminal, a ground terminal, and a heat diffusion layer are provided on a second main surface of the piezoelectric substrate. The first and second electrode lands are electrically connected by first and second connection electrodes to the signal terminal and the ground terminal, respectively. The heat diffusion layer is provided at a position where the heat diffusion layer overlaps at least a portion of the IDT electrodes across the piezoelectric substrate.

An elastic wave device includes a piezoelectric substrate, an IDT electrode on the piezoelectric substrate, and a silicon oxide film arranged on the piezoelectric substrate to cover the IDT electrode. The IDT electrode includes first and second electrode layers laminated on each other, the first electrode layer is made of metal or an alloy with a density higher than a density of metal of the second electrode layer and a density of silicon oxide of the silicon oxide film, the piezoelectric substrate is made of LiNbO.sub.3 and θ is in a range of equal to or greater than about 8° and equal to or less than about 32° with Euler Angles (0°±5°, θ, 0°±10°) of the piezoelectric substrate, and the silicon oxide film contains hydrogen atoms, hydroxyl groups, or silanol groups.

A TF-SAW resonator with improved quality factor is provided. The resonator has its piezoelectric material in the form of a thin film and an electrode structure arranged on the piezoelectric layer. Pitch (P) and metallization ratio (n) are chosen to maximize the quality factor (Q).

An acoustic wave resonator includes: a piezoelectric substrate; and a pair of grating electrodes that is formed on the piezoelectric substrate, one of the pair of grating electrodes including a plurality of first electrode fingers having electric potentials equal to each other, another of the pair of grating electrodes including a plurality of second electrode fingers having electric potentials that differ from the electric potentials of the plurality of first electrode fingers and are equal to each other, two second electrode fingers of the plurality of second electrode fingers being located between at least a pair of adjacent first electrode fingers of the plurality of first electrode fingers, Pg differing from λ/4 where λ represents a wavelength of an acoustic wave excited by the plurality of first electrode fingers and the plurality of second electrode fingers and Pg represents a distance between centers of the two second electrode fingers.

A packaged acoustic wave component includes a support substrate, a multi-layer piezoelectric substrate disposed over a first side of the support substrate, one or more metal layers disposed on a second side of the support substrate that is opposite the first side of the support substrate, and one or more surface acoustic wave resonators or filters disposed over the multi-layer piezoelectric substrate. The one or more surface acoustic wave resonators or filters include a multi-mode surface acoustic wave resonator or filter (e.g., dual mode surface acoustic wave resonator or filter). One or more vias extend through the support substrate and electrically connect the multi-mode surface acoustic wave resonator or filter and the one or more metal layers to provide a ground connection for the multi-mode surface acoustic wave resonator or filter, while reducing parasitic inductance.

An elastic wave filter apparatus includes at least one excitation electrode, a first electrode land, and second electrode lands provided on a first main surface of a device substrate including a piezoelectric layer. A signal terminal and metal members are provided on a second main surface of the device substrate. The first electrode land and the signal terminal are connected to a signal potential, and the second electrode lands and the metal members are connected to a ground potential. A first connection electrode connects the first electrode land and the signal terminal, and a second connection electrode connects at least one of the second electrode lands and at least one of the metal members. The at least one metal member connected to the second connection electrode overlaps at least a portion of the at least one excitation electrode across the device substrate.

A method of manufacturing a packaged acoustic wave component includes forming a support substrate, forming a multi-layer piezoelectric substrate over a first side of the support substrate, and forming one or more metal layers over a second side of the support substrate that is opposite the first side of the support substrate. The method also includes forming one or more surface acoustic wave resonators or filters (including a multi-mode surface acoustic wave resonator or filter) over the multi-layer piezoelectric substrate. The method also includes forming one or more vias through the support substrate, and electrically connecting the multi-mode surface acoustic wave resonator or filter and the metal layers with the vias to provide a ground connection for the multi-mode surface acoustic wave resonator or filter.

An improved DMS filter with electrode structures between a first port and a second port is provided. Wiring junctions are realized in multilayer crossing with dielectric material in between. There are insulating patches (L2) between crossing conductor layers (L1,L3). Signal wirings may be realized with multiple conductor layers (L1, L3) to reduce wiring resistance and the upper conductor layer (L3) of the signal wiring may partly overlap the insulating patches (L2). The insulating patches (L2) may extend over the acoustic path to achieve temperature compensation.

Certain aspects of the present disclosure provide a surface acoustic wave (SAW) device and methods for fabricating such a SAW device. One example SAW device generally includes a piezoelectric substrate, an interdigital transducer (IDT) disposed above the piezoelectric substrate, and a plurality of first regions of dielectric material. The IDT comprises a first electrode having a first plurality of fingers and a second electrode having a second plurality of fingers interdigitated with the first plurality of fingers of the first electrode. The plurality of first regions are disposed above the piezoelectric substrate and between the first and second pluralities of fingers of the IDT, and the dielectric material has a relative permittivity greater than 3.9.

A TF-SAW resonator with improved quality factor is provided. The resonator has its piezoelectric material in the form of a thin film and an electrode structure arranged on the piezoelectric layer. Pitch (P) and metallization ratio (n) are chosen to maximize the quality factor (Q).