An elastic wave device includes a supporting substrate, a high-acoustic-velocity film stacked on the supporting substrate and in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film, a low-acoustic-velocity film stacked on the high-acoustic-velocity film and in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film, the piezoelectric film is stacked on the low-acoustic-velocity film, and an IDT electrode stacked on a surface of the piezoelectric film.

An elastic wave device includes a supporting substrate, a high-acoustic-velocity film stacked on the supporting substrate and in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film, a low-acoustic-velocity film stacked on the high-acoustic-velocity film and in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film, the piezoelectric film is stacked on the low-acoustic-velocity film, and an IDT electrode stacked on a surface of the piezoelectric film.

The present invention provides a method for design acoustic wave RF filter robust against variations of frequency response in passband by resonance frequency modulation of IDT enabling to improve the skirt characteristics in the passband of the filter by resonance frequency modulation with respect to the IDT electrodes of the resonators constituting the acoustic wave filter and determining the design parameters for the IDT electrodes based on the resonance frequency modulation so as to compensate for variations in frequency response due to effects of temperature variations as well as other factors.

The present invention provides a method for design acoustic wave RF filter robust against variations of frequency response in passband by resonance frequency modulation of IDT enabling to improve the skirt characteristics in the passband of the filter by resonance frequency modulation with respect to the IDT electrodes of the resonators constituting the acoustic wave filter and determining the design parameters for the IDT electrodes based on the resonance frequency modulation so as to compensate for variations in frequency response due to effects of temperature variations as well as other factors.

An acoustic wave device includes a piezoelectric layer and an interdigital transducer electrode disposed over the piezoelectric layer. The interdigital transducer electrode is thicker in a center region of the interdigital transducer electrode than in a gap region of the interdigital transducer electrode to thereby reduce a mass loading of the interdigital transducer electrode in the gap region. The interdigital transducer electrode has a layer of more dense material disposed of a layer of less dense material.

An acoustic wave device includes a piezoelectric layer and an interdigital transducer electrode disposed over the piezoelectric layer. The interdigital transducer electrode is thicker in a center region of the interdigital transducer electrode than in a gap region of the interdigital transducer electrode to thereby reduce a mass loading of the interdigital transducer electrode in the gap region. The interdigital transducer electrode has a layer of more dense material disposed of a layer of less dense material.

Systems, methods, and other embodiments described herein relate to estimating direction of a surface acoustic wave (SAW) using temperature measurements from multiple resonators. In one embodiment, a method includes measuring temperatures of multiple resonators that are excited by a SAW using a sensor. The method also includes searching an angle from a temperature ratio of the multiple resonators using the temperatures. The method also includes estimating a direction of the SAW using the angle.

Systems, methods, and other embodiments described herein relate to estimating direction of a surface acoustic wave (SAW) using temperature measurements from multiple resonators. In one embodiment, a method includes measuring temperatures of multiple resonators that are excited by a SAW using a sensor. The method also includes searching an angle from a temperature ratio of the multiple resonators using the temperatures. The method also includes estimating a direction of the SAW using the angle.

A hybrid structure for a surface acoustic wave device comprises a useful layer of piezoelectric material having a first free surface and a second surface disposed on a support substrate that has a lower coefficient of thermal expansion than that of the useful layer, wherein the useful layer comprises an area of nanocavities.

A hybrid structure for a surface acoustic wave device comprises a useful layer of piezoelectric material having a first free surface and a second surface disposed on a support substrate that has a lower coefficient of thermal expansion than that of the useful layer, wherein the useful layer comprises an area of nanocavities.