An oscillating device includes a first quartz crystal resonator, a driving circuit, a first waveform adjustment circuit, and at least two second quartz crystal resonators. The first quartz crystal resonator has a first resonant frequency. The driving circuit, coupled to the first quartz crystal resonator, drives the first quartz crystal resonator to generate a first oscillating signal having the first resonant frequency. The second quartz crystal resonators, coupled in parallel and coupled to the driving circuit and the first quartz crystal resonator, have a second resonant frequency and receive and rectify the first oscillating signal to generate a second oscillating signal having the second resonant frequency. The first waveform adjustment circuit, coupled to the second quartz crystal resonators, receives the second oscillating signal and adjusts the second oscillating signal to generate a first waveform adjustment signal.

An oscillating device includes a first quartz crystal resonator, a driving circuit, a first waveform adjustment circuit, and at least two second quartz crystal resonators. The first quartz crystal resonator has a first resonant frequency. The driving circuit, coupled to the first quartz crystal resonator, drives the first quartz crystal resonator to generate a first oscillating signal having the first resonant frequency. The second quartz crystal resonators, coupled in parallel and coupled to the driving circuit and the first quartz crystal resonator, have a second resonant frequency and receive and rectify the first oscillating signal to generate a second oscillating signal having the second resonant frequency. The first waveform adjustment circuit, coupled to the second quartz crystal resonators, receives the second oscillating signal and adjusts the second oscillating signal to generate a first waveform adjustment signal.

An elastic wave device includes a substrate, an IDT electrode, a spacer layer, a cover, and a protective layer. The spacer layer is provided on the substrate and surrounds the IDT electrode. The cover is provided on the spacer layer, is spaced apart from the IDT electrode, and includes a first main surface adjacent to the spacer layer and a second main surface facing the first main surface. The protective layer includes a third main surface contacting the second main surface, a fourth main surface facing the third main surface, and a side surface connected to the fourth main surface. In at least portion of the side surface of the protective layer, a portion including an intersection line between the side surface and the fourth main surface is located farther inward than an outer edge of the substrate in plan view in the thickness direction of the substrate.

A surface acoustic wave device has a piezoelectric substrate having a cut angle (e.g., the piezoelectric angle is cut so as to have a crystal orientation) that allows the surface acoustic wave device to operate as a longitudinally leaky surface acoustic wave device that confines the acoustic wave energy within the piezoelectric substrate and that has less propagation attenuation and a higher electromechanical coupling coefficient k.sup.2.

A measuring system is disclosed. The measuring system includes a surface acoustic wave (SAW) device including a piezoelectric substrate and a first and second electrode disposed on a surface of the piezoelectric substrate, and a measuring device communicatively coupled to the first electrode via a first probe and the second electrode via a second probe and configured to apply an electrical signal to the first and second electrode to generate an incident bulk acoustic wave within the piezoelectric substrate, detect at least a first reflected bulk acoustic wave and a second reflected bulk acoustic wave at the first and second electrode, and calculate a thickness between a first interface corresponding to the first reflected bulk acoustic wave and a second interface corresponding to the second reflected bulk acoustic wave based on a time elapsed between detecting the first and second reflected bulk acoustic waves.

A surface acoustic wave device (5) is provided using a layered substrate system with a special material and a special cut of a piezoelectric thin film (4) selected for utilizing Rayleigh mode. The proper choice of the material and the cut of the piezoelectric thin film leads to a low velocity of the excited wave mode, which allows the usage of smaller devices without deteriorating other performance parameters according to specifications.

The invention relates to a SAW resonator (100) comprising at least: a substrate (102); a layer (108) of piezoelectric material arranged on the substrate; a first attenuation layer (112) arranged between the substrate and the layer of piezoelectric material, and/or, when the substrate comprises at least two different layers (104, 106), a second attenuation layer (114) arranged between the two layers of the substrate; and in which the at least one attenuation layer is/are heterogeneous.

An acoustic wave device includes a piezoelectric layer, an IDT electrode, a high-acoustic-velocity support substrate, and a low-acoustic-velocity film. The high-acoustic-velocity support substrate is located on an opposite side of the piezoelectric layer from the IDT electrode in the thickness direction of the piezoelectric layer. The low-acoustic-velocity film is disposed between the high-acoustic-velocity support substrate and the piezoelectric layer in the thickness direction. The high-acoustic-velocity support substrate includes a base region and a surface region disposed nearer to the low-acoustic-velocity film than the base region in the thickness direction and whose crystal quality is worse than that of the base region. The surface region includes first and second layers disposed nearer to the base region than the first layer in the thickness direction and whose crystal quality is better than that of the first layer.

A method of manufacturing a bonded substrate, which has a quartz substrate and a piezoelectric substrate bonded, includes irradiating a bonding surface of the quartz substrate and a bonding surface of the piezoelectric substrate with ultraviolet light under a pressure lower than atmosphere pressure. After the irradiation, the bonding surface of the quartz substrate and the bonding surface of the piezoelectric substrate are brought into contact. And the quartz substrate and the piezoelectric substrate are pressurized in a thickness direction to bond the bonding surfaces.

An acoustic wave sensor device, comprising an interdigitated transducer; a first reflection structure arranged on one side of the interdigitated transducer, and a second reflection structure arranged on another side of the interdigitated transducer; a first resonance cavity comprising a first upper surface and formed between the interdigitated transducer and the first reflection structure; a second resonance cavity comprising a second upper surface and formed between the interdigitated transducer and the second reflection structure; and wherein the second upper surface comprises a physical and/or chemical modification as compared to the first upper surface.