A surface elastic wave filter has resonant cavities and comprises a composite substrate formed of a base substrate and a piezoelectric upper layer; at least one input electroacoustic transducer and an output electroacoustic transducer, arranged on the upper layer, and at least one internal reflecting structure, arranged between the input electroacoustic transducer and the output electroacoustic transducer. The internal reflecting structure comprises a first structure comprising at least one reflection grating having a first period and a second structure comprising at least one reflection grating having a second period, the first period being greater than the second period.

A surface elastic wave filter has resonant cavities and comprises a composite substrate formed of a base substrate and a piezoelectric upper layer; at least one input electroacoustic transducer and an output electroacoustic transducer, arranged on the upper layer, and at least one internal reflecting structure, arranged between the input electroacoustic transducer and the output electroacoustic transducer. The internal reflecting structure comprises a first structure comprising at least one reflection grating having a first period and a second structure comprising at least one reflection grating having a second period, the first period being greater than the second period.

A surface acoustic wave resonator includes an IDT that is disposed on a quartz crystal substrate of Euler angles (1.51.5, 117142, ) and excites a surface acoustic wave resonant in an upper part of a stop-band of the IDT, and inter-electrode finger grooves that are acquired by depressing the substrate located between electrode fingers configuring the IDT. The wavelength of the surface acoustic wave, the depth of the inter-electrode finger grooves, the line occupancy ratio of the IDT, and the film thickness of the electrode fingers of the IDT are set in correspondence with one another.

A method of forming an acoustic wave device is disclosed. The method can include providing a structure having a support substrate that includes a first substrate portion, a second substrate portion, and a third substrate portion between the first portion and the second portion, a piezoelectric layer that includes a first portion over the first substrate portion and a second portion over the second substrate portion, a first interdigital transducer electrode on the first portion of the piezoelectric layer, and a second interdigital transducer electrode on the second portion of the piezoelectric layer. the method can also include etching at least a portion of the piezoelectric layer such that a region over the third substrate portion is free from the piezoelectric layer.

An apparatus is disclosed for implementing a surface-acoustic-wave (SAW) filter with dielectric material disposed in a piezoelectric layer. In an example aspect, the apparatus includes a surface-acoustic-wave filter with a piezoelectric layer, an electrode structure, and dielectric material. The piezoelectric layer has at least one channel. The dielectric material is disposed in the at least one channel of the piezoelectric layer and is at least partially covered by the electrode structure.

An acoustic wave device is disclosed. The acoustic wave device can include a support substrate that includes a first substrate portion, a second substrate portion, and a third substrate portion between the first substrate portion and the second substrate portion. The acoustic wave device can include a piezoelectric layer that includes a first portion over the first substrate portion and a second portion over the second substrate portion. The piezoelectric layer can be arranged such that a region over the third substrate portion is free from the piezoelectric layer. The acoustic wave device can include a filter circuit formed on the first portion of the piezoelectric layer. The acoustic wave device can include a cancelation circuit on the second portion of the piezoelectric layer.

Disclosed is a quartz oscillator including a first cover, a second cover, and a quartz oscillation device. The quartz oscillation device is disposed between the first cover and the second cover. The quartz oscillation device includes a quartz sheet, a first conductive layer and a second conductive layer. The first conductive layer is disposed on the first surface of the quartz sheet. The second conductive layer is disposed on the second surface of the quartz sheet. The quartz sheet has a groove or an opening penetrating therethrough. An included angle between a side wall of the groove or the opening and the first surface or the second surface is 60 to 90.

Disclosed is a quartz oscillation device including a quartz sheet, a first conductive layer and a second conductive layer. The first conductive layer is disposed on the first surface of the quartz sheet. The second conductive layer is disposed on the second surface of the quartz sheet. The quartz sheet has a groove or an opening penetrating therethrough. An included angle between a side wall of the groove or the opening and the first surface or the second surface is 60 to 90.