Abstract: Methods and systems described herein relate to broadcasting on a wireless channel. An example method includes generating, based on data, a data signal including one or more data packets, where each of the one or more data packets is a non-connectable and non-scannable data packet. The method further includes generating a plurality of RF signals of different frequencies using an oscillator circuit, directly modulating at least one of the RF signals, based on the data signal, to generate a modulated RF signal, amplifying the modulated RF signal, and broadcasting the amplified modulated RF signal on the wireless channel.

Abstract: An ultrasonic device includes a substrate, a first piezoelectric body, a second piezoelectric body, and an acoustic matching section. The substrate has a first surface that is a flat surface. The first piezoelectric body is disposed on the first surface of the substrate. The second piezoelectric body is disposed on the first surface of the substrate. The second piezoelectric body has a different thickness from a thickness of the first piezoelectric body as measured from the first surface of the substrate. The acoustic matching section is disposed on the first piezoelectric body and the second piezoelectric body. The acoustic matching section has a first side facing the first piezoelectric body and the second piezoelectric body, and a second side opposite from the first side. A surface of the acoustic matching section on the second side is a flat surface parallel with the first surface of the substrate.

Abstract: A vibration motor is provided in the present disclosure. The vibration motor includes a frame, vibrating assemblies and elastic connectors. The elastic connectors comprise a first elastic connector and a second elastic connector. The vibrating assemblies comprise a first vibration system and a second vibration system disposed at two sides of the frame respectively. A portion of the first elastic connector is connected with the first vibration system and another portion of the first elastic connector is connected with one side of the frame, and a portion of the second elastic connector is connected with the second vibration system and another portion of the second elastic connector is connected with the other side of the frame. The first vibration system comprises a coil, the second vibration system comprises a magnetic circuit system with a magnetic gap, at least part of the coil is disposed in the magnetic gap.

Abstract: A method of tuning the resonant frequency of embedded bulk acoustic resonators during manufacturing of an integrated circuit. The rate of change in the resonant frequency of BAWs vs rate of change in top electrode thickness is determined and used to tune the resonant frequency of embedded bulk acoustic resonators during integrated circuit manufacturing.

Abstract: A BAW component is provided. A method for manufacturing a BAW component is also provided. The component includes a bottom electrode, a top electrode and a first piezoelectric material. The first piezoelectric material is between the bottom electrode and the top electrode. The first piezoelectric material has a higher piezoelectric coefficient than AlN.

Abstract: A piezoelectric resonator that includes a single crystal Si layer, a piezoelectric thin film formed from aluminum nitride and provided on the single crystal Si layer, and first and second electrodes provided so as to sandwich the piezoelectric thin film. An element excluding nitrogen and aluminum is doped into the piezoelectric thin film formed from aluminum nitride, and a synthetic acoustic velocity of portions of the piezoelectric resonator other than the single crystal Si layer substantially coincide with the acoustic velocity of the single crystal Si layer.

Abstract: A bulk acoustic wave resonator includes a substrate, a first electrode and a second electrode disposed on the substrate, and a piezoelectric layer disposed between the first electrode and the second electrode. At least one of the first electrode and the second electrode includes an alloy of molybdenum and tantalum.

Abstract: Embodiments of a tunable radio frequency (RF) diplexer and methods of duplexing transmission and receive signals are disclosed. In one embodiment, the RF diplexer includes a first hybrid coupler, a second hybrid coupler, and an RF filter circuit, and a phase inversion component. Both the RF filter circuit and the phase inversion component are connected between the first hybrid coupler and the second hybrid coupler. In some embodiments, the phase inversion component is provided by the RF filter circuit, while in other embodiments, the phase inversion component is provided separately. The phase inversion component is configured to provide a differential phase shift. The benefit of introducing the differential phase shift is that it provides increased isolation and broadband isolation between the different frequency bands being diplexed by the RF diplexer.

Abstract: A radio frequency filter and a manufacturing method thereof are provided. A radio frequency filter includes bulk acoustic wave resonators (BAWRs), the BAWRs including first BAWRs connected in series, second BAWRs connected in parallel, or a combination thereof.

Abstract: A piezoelectric component which suppress ripples in the range of oscillation frequency and achieves stabilization of oscillation frequency is provided. A piezoelectric component of the invention includes a support substrate; a piezoelectric element having an elongated shape, comprising excitation electrodes disposed on one principal surface and the other principal surface thereof, respectively, the excitation electrodes facing each other; a first support portion and a second support portion which are disposed between both ends in a longitudinal direction of the piezoelectric element and the support substrate; and an electrically conductive joining material which joins the first support portion and the second support portion to the ends of the piezoelectric element, respectively. A center of the piezoelectric element is offset with respect to an intermediate point between the first support portion and the second support portion as seen in a plan view of the piezoelectric component.

Abstract: A piezoelectric vibration element includes a piezoelectric substrate including a thin vibration region and a thick section integrated along three sides excluding one side of the vibration region, excitation electrodes respectively arranged on the front and rear surfaces of the vibration region, and lead electrodes. The thick section includes a first thick section and a second thick section arranged to be opposed to each other across the vibration region and a third thick section connected between proximal ends of the first and second thick sections. The second thick section includes an inclined section connected to the one side of the vibration region, a second thick section main body connected to the other side of the inclined section, and at least one slit for stress relaxation.

Abstract: A vibrating device that is in the form of a rectangular plate having opposed long sides and opposed short sides, and that utilizes an expanding and contracting vibration mode in a direction of the short sides. The vibrating device includes a Si layer made of a degenerate semiconductor, a silicon oxide layer, a piezoelectric layer, and first and second electrodes through which a voltage is applied to the piezoelectric layer. When a total thickness of the Si layer is denoted by T1, a total thickness of the silicon oxide layer is denoted by T2, and the TCF in the vibrating device when the silicon oxide layer 3 is not provided is denoted by x(ppm/K), T2/(T1+T2) is within a range of (?0.0003x2?0.0256x+0.0008)±0.05.

Abstract: Embodiments of a tunable radio frequency (RF) diplexer and methods of operating the same are disclosed. In one embodiment, the RF diplexer includes a first hybrid coupler, a second hybrid coupler, an RF filter circuit, and a phase inversion component. Both the RF filter circuit and the phase inversion component are connected between the first hybrid coupler and the second hybrid coupler. The phase inversion component is configured to provide approximately a differential phase. The RF filter circuit is configured to provide a passband and a notch. The RF filter circuit is tunable to provide the notch on both a high-frequency side of the passband and a low frequency side of the passband. Accordingly, the tunable RF diplexer provides lower insertion losses and higher isolation regardless of whether the one of the diplexed frequency bands is set at higher frequencies or lower frequencies than the other diplexed frequency band.

Abstract: Biosensor apparatus and associated method for detecting a target material using a vibrating resonator having a surface that operably interacts with the target material. A detector is in electrical communication with a sensor, the sensor comprising a first paddle assembly connected to a second paddle assembly, the first paddle assembly having at least one microbalance sensing resonator proximate a proximal end and at least one sensing electrical contact proximate a distal end in electrical communication with the sensing resonator. The at least one sensing resonator has a target coating for operably interacting with the target material, and the second paddle assembly has a microbalance reference resonator proximate the proximal end and at least one reference electrical contact proximate the distal end in electrical communication with the reference resonator.

Abstract: A resonator element includes a substrate that vibrates in a thickness shear vibration, a first excitation electrode that is provided on one main surface of the substrate and has a shape in which at least three corners of a virtual quadrangle are cut out, and a second excitation electrode that is provided on the other main surface of the substrate, and a ratio (S2/S1) of an area S1 of the virtual quadrangle and an area S2 of the first excitation electrode satisfies a relationship of 69.2%?(S2/S1)?80.1%.

Abstract: The present invention relates to a BAW filter operating with bulk acoustic waves, which has a multilayer construction, wherein functional layers of a BAW resonator operating with bulk acoustic waves are realized by the multilayer construction, and wherein an interconnection of passive components is furthermore formed by the multilayer construction, said interconnection forming a balun, wherein the balun has at least one inductance (L1, L2, L3) and at least one capacitance (C1, C2) which are formed from structured functional layers of the BAW resonator. Furthermore, the invention relates to a method for producing the BAW filter.

Abstract: A wave generator has a wave emitter including an elongated dispersive waveguide and a source operatively connected to a first end of the waveguide. The source covers at least partially a surface area thereof. A signal generator is in operative connection with the transducer to create electrical signals. A computer is in operative connection with the signal generator to cause it to generate the electrical signals. A mechanical input wave is created by the source at the first end of the waveguide. The mechanical input wave is constructed independently of data related to a mechanical wave received from a source in the medium and taking into account the different predetermined propagation velocities of at least two component waves of the mechanical input wave so that they combine with each other at a second end of the waveguide to form the desired mechanical output wave in the medium.

Abstract: A piezoelectric bulk wave device that includes a piezoelectric thin plate that is made of LiTaO3, and first and second electrodes that are provided in contact with the piezoelectric thin plate. The piezoelectric bulk wave device utilizes the thickness shear mode of the piezoelectric thin plate made of LiTaO3, and of the Euler Angles (?, ?, ?) of LiTaO3, ? is 0°, and ? is in the range of not less than 54° and not more than 107°.

Abstract: A resonator element includes a vibrating portion that vibrates in a thickness shear vibration and includes a first main surface and a second main surface which are in a front and back relationship to each other, a first excitation electrode that is provided on the first main surface, and a second excitation electrode that is provided on the second main surface, and an energy trapping coefficient M satisfies a relationship of 33.6?M?65.1.

Abstract: An acoustic wave device includes: a substrate; a piezoelectric film located on the substrate; a lower electrode and an upper electrode facing each other across at least a part of the piezoelectric film; a silicon oxide film located at an opposite side of at least one of the lower electrode and the upper electrode from the piezoelectric film; a non-oxygen-containing insulating film located between the at least one of the lower electrode and the upper electrode and the silicon oxide film; and an additional film located at an opposite side of the silicon oxide film from the non-oxygen-containing insulating film and made of a material different from a material of the silicon oxide film.

Abstract: Embodiments of a Bulk Acoustic Wave (BAW) resonator in which an outer region of the BAW resonator is engineered in such a manner that lateral leakage of mechanical energy from an active region of the BAW resonator is reduced, and methods of fabrication thereof, are disclosed. In some embodiments, a BAW resonator includes a piezoelectric layer, a first electrode on a first surface of the piezoelectric layer, a second electrode on a second surface of the piezoelectric layer opposite the first electrode, and a passivation layer on a surface of the second electrode opposite the piezoelectric layer, the passivation layer having a thickness (TPA). The BAW resonator also includes a material on the second surface of the piezoelectric layer adjacent to the second electrode in an outer region of the BAW resonator. The additional material has a thickness that is n times the thickness (TPA) of the passivation layer.

Abstract: A piezoelectric thin film resonator includes: a lower electrode and an upper electrode facing each other across a piezoelectric film; an insertion film inserted into the piezoelectric film, located in at least a part of an outer peripheral region in a resonance region and outside the outer peripheral region, and not located in a center region of the resonance region; a protective film on the upper electrode and the piezoelectric film; and a wiring line connecting to the lower electrode and covering an outer periphery of the protective film in an extraction region of the lower electrode, wherein in the extraction region, an outer periphery of the insertion film is further out than an outer periphery of the upper electrode and further in than an outer periphery of the piezoelectric film, and the outer periphery of the protective film is further out than the outer periphery of the insertion film.

Abstract: A high-speed electrical connector employs a plurality of electrical contacts held together by a dielectric frame. The contacts are electrically coupled to a substrate within the connector. A gasket may be disposed between the dielectric frame and the substrate and configured to block the flow of an overmold material between the dielectric frame and the substrate such that voids are formed between the contacts. The dielectric frame and the overmold may be made from materials containing silica aerogel. The voids and the aerogel materials result in reduced parasitic capacitance between the contacts enabling higher data transfer speeds.

Abstract: In a piezoelectric device, an ultrasound probe, and a droplet discharge unit of the present invention, each of a pair of first and second electrodes is placed on a piezoelectric member having a single orientation in a direction perpendicular to a thickness direction thereof to extend in a direction perpendicular to the thickness direction or along the thickness direction and in a direction perpendicular to the direction of the orientation. Therefore, the piezoelectric device of the present invention has excellent piezoelectric properties. Further, the ultrasound probe and the droplet discharge unit of the present invention have good efficiency.

Abstract: An acoustic resonator structure comprises a piezoelectric layer having a first surface and a second surface, a first electrode disposed adjacent to the first surface, and a second electrode disposed adjacent to the second surface. The first electrode comprises a first conductive layer disposed adjacent to the piezoelectric layer and having a first acoustic impedance, and a second conductive layer disposed on a side of the first conductive layer opposite the piezoelectric layer and having a second acoustic impedance greater than the first acoustic impedance. The second electrode may be disposed between a substrate and the piezoelectric layer, and it may comprise a third conductive layer disposed adjacent to the piezoelectric layer and having a third acoustic impedance, and a fourth conductive layer disposed on a side of the third conductive layer opposite the piezoelectric layer and having a fourth acoustic impedance greater than the third acoustic impedance.

Abstract: A mesa-shaped piezoelectric resonator element including a resonator section having a thicker thickness than a peripheral section on the board surface of a piezoelectric substrate formed in a rectangular shape, wherein, when the length of the long side of the piezoelectric substrate is x and the board thickness of the resonator section is t, etching depth y of a level-difference section is set to fulfill a relationship in the following equation, based on the board thickness t. y = - 1.

Abstract: To provide a small-sized piezoelectric vibrating reed and a piezoelectric vibrator with excellent durability. The piezoelectric vibrating reed includes a piezoelectric plate having a rectangular shape, a vibrating portion formed on a principal surface of the piezoelectric plate and a pair of mount portions for mounting the piezoelectric plate. The pair of mount portions are formed at both end portions of the piezoelectric plate in a longitudinal direction. The piezoelectric vibrator includes the piezoelectric vibrating reed and a package on which the mount portions of the piezoelectric vibrating reed are mounted.

Abstract: A resonator element includes a thick section, a middle section and a thin section, in which at least the thick section performs thickness shear vibration, in which a first step difference is provided at a boundary between the thick section and the middle section, and a second step difference is provided at a boundary between the middle section and the thin section, on one side of a direction of the thickness shear vibration, in which a first antinode of flexural vibration is located between the first step difference and the second step difference, and in which, a distance between the first antinode and the first step difference is indicated by d1, a distance between the first antinode and the second step difference is indicated by d2, and a wavelength of the flexural vibration is indicated by ?, a relationship of 0?d1??/8 and 0?d2??/8 is satisfied.

Abstract: A piezoelectric thin-film resonator includes, a substrate, a piezoelectric film provided on the substrate, and a lower electrode and an upper electrode that face each other through the piezoelectric film. The piezoelectric film has an air space that is provided in at least part of an outer circumferential part of a resonance region in which the upper and lower electrodes face each other through the piezoelectric film and is not provided in a central part of the resonance region.

Abstract: The present invention relates to a transducer (11) comprising—a membrane (31) configured to change shape in response to a force, the membrane (31) having a first major surface (16) and a second major surface (17), —a piezoelectric layer (18) formed over the first major surface (16) of the membrane (31), the piezoelectric layer (18) having an active portion, —first and second electrodes (19) in contact with the piezoelectric layer (18), wherein an electric field between the first and second electrodes (19) determines the mechanical movement of the piezoelectric layer (18), —support structures (40) at the second major surface (17) of the membrane (15) on adjacent sides of the active portion of the piezoelectric layer (18), at least part of the support structures (40) forming walls perpendicular, or at least not parallel, to the second major surface (17) of the membrane (31), so as to form a trench (41) of any shape underlying the active portion, so that an ultrasound transducer is obtained with a high output pr

Abstract: Provided are a resonator and a method of fabricating the same. The resonator may include a first electrode disposed on a substrate, a piezoelectric layer disposed on the first electrode, a second electrode disposed on the piezoelectric layer, and a control layer disposed on the second electrode and having a frame with an uneven surface.

Abstract: An integrated circuit device includes a piezoelectric substrate having a first surface and a second surface opposite the first surface. The device also includes a first electrode and a second electrode on the first surface of the piezoelectric substrate, the first electrode having a first width and the second electrode having a second width. The device further includes a third electrode and a fourth electrode on the second surface of the piezoelectric substrate, the third electrode having a third width that is substantially the same as the second width, and the fourth electrode having a fourth width that is substantially the same as the first width. The first and third electrodes operate as part of a first portion of a microelectromechanical systems (MEMS) resonator, and the second and fourth electrodes operate as part of a second portion of the MEMS resonator.

Abstract: This disclosure provides methods of fabricating a transducer array. The methods can include creating a lens shaped depression in a backing material, printing an electrode, printing a thick layer of lead zirconate titanate material, printing a ground electrode, and placing a plurality of equally spaced cuts into the depression.

Abstract: Systems and devices adapted to reduce disturbances and windage effects in a turbine during operation are disclosed. In one embodiment, a cap includes: a body portion having a shape complementary to an aperture in a turbine component, the body portion including an external surface which substantially covers the aperture; and a cap groove formed in a circumferential surface of the body portion, the cap groove configured to substantially align with a component groove formed in the aperture.

Abstract: The electromagnetic resonance coupler includes: a transmission substrate; a reflective substrate; the first resonant wiring having an open loop shape having a first opening; a first input/output wiring connected to the first resonant wiring; the second resonant wiring provided inside the first resonant wiring and having an open loop shape having a second opening; a second input/output wiring connected to the second resonant wiring, the first resonant wiring, the first input/output wiring, the second resonant wiring, and the second input/output wiring being provided on the transmission substrate; and a reflection wiring provided on the reflective substrate and having a open loop shape having a third opening, in which, when viewed in a direction perpendicular to a main face of the transmission substrate, the reflection wiring and the first resonant wiring overlap and the reflection wiring and the second resonant wiring overlap.

Abstract: An oscillation structure of micro actuator is described. In the oscillation structure, a pair of torsion bars is disposed along a first axis perpendicular to a second axis. The first frame is connected to the pair of torsion bars wherein the torsion bars are disposed on the outer periphery of a first frame along the first axis and a second frame is disposed inside the first frame. Each of the first connection members connects the first frame to the second frame therebetween, and each of the second connection members connects the second frame to the oscillation body therebetween such that the first frame, the second frame and the oscillation body are allowed to rotate about the first axis by the torsion bars as a structure assemblies at an identical angle. The oscillation structure effectively reduces the dynamic deformation of micro actuator.

Abstract: A piezoelectric vibration element includes a piezoelectric piece, a pair of excitation electrodes, and a pair of extraction electrodes. The piezoelectric piece has a rectangular shape with long sides and short sides and a first principal surface and a second principal surface. The piezoelectric piece includes a mesa portion thicker than a peripheral portion at least on the first principal surface. The excitation electrode is larger than an area of the mesa portion and covers the mesa portion on the principal surface where the mesa portion is formed. The excitation electrode has a center away from a center of the piezoelectric piece toward another short side by a first distance. The mesa portion has a center away from the center of the piezoelectric piece to the other short side by a second distance. The second distance is different from the first distance.

Abstract: A film bulk acoustic resonator (FBAR) structure includes a first electrode disposed over a substrate, a piezoelectric layer disposed over the first electrode, and a second electrode disposed over the first piezoelectric layer. A bridge is disposed between the first electrode and the piezoelectric layer.

Abstract: In accordance with a representative embodiment, a bulk acoustic wave (BAW) resonator structure, comprises: a first BAW resonator comprising a first lower electrode, a first upper electrode and a first piezoelectric layer disposed between the first lower electrode and the first upper electrode; a second BAW resonator comprising a second lower electrode, a second upper electrode and a second piezoelectric layer disposed between the second lower electrode and the second upper electrode; an acoustic coupling layer disposed between the first BAW resonator and the second BAW resonator; and a bridge disposed between the first lower electrode of the first BAW resonator and the second upper electrode of the second BAW resonator.

Abstract: According to an exemplary embodiment, a bulk acoustic wave structure includes a lower electrode situated over a substrate. The bulk acoustic wave structure further includes a piezoelectric layer situated over the lower electrode, where the piezoelectric layer comprises aluminum copper nitride. The bulk acoustic wave structure further includes an upper electrode situated over the lower electrode. The bulk acoustic wave structure can further include a bond pad connected to the upper electrode, where the bond pad comprises aluminum copper. The lower electrode can include a high density metal situated adjacent to the piezoelectric layer and a high conductivity metal layer underlying the high density metal layer.

Abstract: In accordance with a representative embodiment, a bulk acoustic wave (BAW) resonator structure, comprises: a first BAW resonator comprising a first lower electrode, a first upper electrode and a first piezoelectric layer disposed between the first lower electrode and the first upper electrode; a second BAW resonator comprising a second lower electrode, a second upper electrode and a second piezoelectric layer disposed between the second lower electrode and the second upper electrode; an acoustic coupling layer disposed between the first BAW resonator and the second BAW resonator; and a bridge disposed between the first lower electrode of the first BAW resonator and the second upper electrode of the second BAW resonator. An inner raised region or an outer raised region, or both are disposed over the second upper electrode.

Abstract: A resonator element includes a substrate including a vibrating portion that performs thickness-shear vibration and an excitation electrode provided on top and bottom main surfaces of the vibrating portion. Assuming that the average plate thickness calculated from the plate thicknesses of a plurality of regions of the vibrating portion is H and the plate thickness difference, which is a difference between the maximum and minimum values of the plate thicknesses of the plurality of regions of the vibrating portion, is ?H, 0%<?H/H?0.085% is satisfied as a relationship between H and ?H.

Abstract: A TPoS resonator includes a substrate and a resonator body suspended over the substrate by at least a first pair of fixed supports (e.g., tethers) that attach to first and second ends of the resonator body. The resonator body includes monocrystalline silicon, which has a [100] crystallographic orientation that is offset by ±? degrees relative to a nodal line of the resonator body (e.g., tether-to-tether axis) when the resonator body is operating at a resonant frequency, where a is a real number in a range from about 5 to about 19 and, more preferably, in a range from about 7 to about 17. The resonator may be an extensional-mode resonator and the resonator body may be rectangular-shaped with unequal length and width dimensions.

Abstract: A piezoelectric vibration element includes a piezoelectric substrate including a thin vibration region and a thick section integrated along three sides excluding one side of the vibration region, excitation electrodes respectively arranged on the front and rear surfaces of the vibration region, and lead electrodes. The thick section includes a first thick section and a second thick section arranged to be opposed to each other across the vibration region and a third thick section connected between proximal ends of the first and second thick sections. The second thick section includes an inclined section connected to the one side of the vibration region, a second thick section main body connected to the other side of the inclined section, and at least one slit for stress relaxation.

Abstract: The disclosure provides a structure for a microelectromechanical system (MEMS)-based resonator device. The structure for the MEMS-based resonator device includes at least one resonator unit. The at least one resonator unit comprises a substrate having a trench therein. A pair of first electrodes is disposed on a pair of sidewalls of the trench. A piezoelectric material fills the trench, covering the pair of first electrodes. A second electrode is embedded in the piezoelectric material, separated from the pair of first electrodes by the piezoelectric material. The second electrode disposed in the trench is parallel to the pair of first electrodes.

Abstract: A method for manufacturing piezoelectric resonator devices according to the present invention includes the following steps: a wafer forming step of preparing a thick-walled wafer 30 integrally formed with multiple lower lid members 3; a bonding step of bonding crystal resonator plates 2 to one main surface 31 of the wafer 30 via a bonding material 5 and bonding upper lid members 4 on the crystal resonator plates via a bonding material 5; a thinning step of thinning the wafer 30 from the other main surface 37 of the wafer; an external terminal forming step of forming external terminals on the other main surface of the thinned wafer; and a dividing step of cutting the wafer between each adjacent pair of crystal resonators so that multiple crystal resonators are obtained.

Abstract: An AT-cut quartz plate having chamfered ridge portions and an almost rectangular shape in planar view, wherein a resonance frequency is equal to or larger than 7 MHz and equal to or smaller than 9 MHz, lengths of long and short sides of the rectangular shape are equal to or larger than 1.5 mm and equal to or smaller than 2.4 mm, and equal to or larger than a frequency difference between primary vibration and sub-vibration is equal to or larger than 975 kHz and equal to or smaller than 1,015 kHz.

Abstract: A tunable acoustic resonator device has a piezoelectric medium as a first thin film layer and a tunable crystal medium as a second thin film layer. The tunable crystal medium has a first acoustic behavior over an operating temperature range under a condition of relatively low applied stress and a second acoustic behavior under a condition of relatively high applied stress. The acoustic behaviors are substantially different and, consequently, the different levels of applied stress are used to tune the acoustic resonator device. Compared with the tunable resonator device consisting of only tunable crystal medium, a device having both the piezoelectric and tunable crystal medium has advantages such as larger inherent bandwidth and less nonlinearity with AC signals. The device also requires a smaller applied stress (i.e. bias voltage) to achieve the required frequency tuning.

Abstract: In a piezoelectric device, a lower covering layer, a piezoelectric material layer, a lower electrode layer, and an upper electrode layer, which define common layers, and an upper covering layer, which defines a specific layer, are laminated on a substrate. The piezoelectric material layer is sandwiched between a pair of electrodes. First to third vibration regions are provided in which the electrodes are superimposed with the piezoelectric material layer therebetween when viewed in a transparent manner in the direction in which the layers are laminated. The upper covering layer includes only a portion having with a first thickness in the first vibration region, includes a portion having the first thickness and a portion having a second thickness that is smaller than the first thickness in the second vibration region, and includes only a portion having the second thickness in the third vibration region.

Abstract: An acoustic wave device includes: a piezoelectric thin film resonator including: a substrate; a lower electrode formed on the substrate; at least two piezoelectric films formed on the lower electrode; an insulating film sandwiched by the at least two piezoelectric films; and an upper electrode formed on the at least two piezoelectric films, wherein an area of the insulating film within a resonance region, in which the lower electrode and the upper electrode face each other across the at least two piezoelectric films, is different from an area of the resonance region.