Abstract: Aspects of this disclosure relate to a bulk acoustic wave device with a multi-gradient raised frame. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient raised frame structure configured to cause lateral energy leakage from a main acoustically active region of the bulk acoustic wave device to be reduced. The multi-gradient raised frame structure is tapered on opposing sides.

Abstract: A resonator device includes: a base; a resonator element that includes a resonator substrate and an electrode; a conductive layer that is disposed on the base; a metal bump that is disposed between the conductive layer and the resonator element, and that electrically couples the conductive layer and the electrode while bonding the conductive layer and the resonator element; and at least one of a first low elastic modulus layer that is interposed between the base and the conductive layer, that overlaps the metal bump in a plan view of the base, and that has an elastic modulus smaller than that of the metal bump, and a second low elastic modulus layer that is interposed between the resonator substrate and the electrode, that overlaps the metal bump in the plan view of the base, and that has an elastic modulus smaller than that of the metal bump.

Abstract: Aspects of this disclosure relate to an acoustic wave filter that includes a series a bulk acoustic wave resonator having a plurality of anti-resonant frequencies that impact a passband of the acoustic wave filter. Related bulk acoustic wave resonators, radio frequency modules, wireless communication devices, and methods of filtering radio frequency signals are disclosed.

Abstract: An electrostatic transducer (1) includes: an insulator sheet (11); a first electrode sheet (12); a lead (30); a first bonding part (61), electrically bonding the first electrode sheet (12) with a core wire (30a) of the lead (30) in a first area (Pa) where the first electrode sheet (12) and the core wire (30a) of the lead (30) are disposed overlapping each other; and a second bonding part (62), bonding the insulator sheet (11) with a coating (30b) of the lead (30) in a second area (Pb) where the insulator sheet (11) and the coating (30b) of the lead (30) are disposed overlapping each other.

Abstract: A transducer comprises two piezoelectric layers attached to a substrate, two protective layers, two masses, and two stiffeners arranged at the ends of the bimorph. The transducer is made using a composite bagging process and autoclave curing. The transducer is attached to a flat panel using a parallelogram-shaped double-sided tape to form a loudspeaker or a display panel with haptic feedback. The improved transducer enables a full-range flat panel speaker with uniform frequency response over its operating frequency.

Abstract: A guided acoustic wave device includes a substrate, a lithium tantalate layer on the substrate, and a transducer on the lithium tantalate film. The lithium tantalate has a crystalline orientation defined by (YXl)?°, where ? is between 10° and 37°. The inventors discovered that limiting the crystalline orientation of the lithium tantalate in this manner provides significant increases in the electromechanical coupling coefficient of the acoustic wave device, thereby increasing bandwidth and improving performance.

Abstract: Disclosed are a conductive film for a sound producing apparatus, and a sound producing apparatus. The conductive film includes a conductive layer and substrate layers bonded to two surfaces of the conductive layer, the substrate layers comprising two first substrate layers directly bonded to the conductive layer, the first substrate layers being made of a thermoplastic elastomer, and the first substrate layers are connected with the conductive layer by means of hot pressing.

Abstract: Sufficient sound pressure is obtained in the mid-low range, to provide a SoT module 100 which can be applied to a variety of applications. A SoT module 100 comprises a plate-shaped piezoelectric composite 105 for generating bending vibration by the impression of an AC voltage, a plurality of elastic bodies, one ends of which are bonded to the main surface of the piezoelectric composite 105, the elastic bodies 120a and 120b transmitting vibration of the piezoelectric composite 105 and a vibration plate 130 has a main surface which is bonded to the other ends of the elastic bodies 120a and 120b, wherein the piezoelectric composite 105 comprises piezoelectric elements 110a, 110b formed in a rectangular plate, and there is a position of the centroid of the piezoelectric composite 105 between the plurality of elastic bodies 120a and 120b.

Abstract: Methods of fabricating resonator and filter devices. A first conductor pattern formed on a front surface of a piezoelectric plate includes a first plurality of contact pads and an interdigital transducer (IDT). The IDT and the piezoelectric plate are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic mode within the piezoelectric plate. An acoustic Bragg reflector is between a substrate and a back surface of the piezoelectric plate, the acoustic Bragg reflector configured to reflect the shear primary acoustic mode. A second conductor pattern including a second plurality of contact pads is formed on a back surface of the interposer. The first plurality of contact pads is directly connected to respective contact pads of the second plurality of contact pads. A perimeter of the acoustic resonator chip is sealed to a perimeter of the interposer.

Abstract: Resonator and filter devices and methods of fabrication. A resonator chip includes a substrate, a piezoelectric plate, and an acoustic Bragg reflector between the substrate and a back surface of the piezoelectric plate. A conductor pattern on a front surface of the piezoelectric plate includes a first plurality of contact pads and an interdigital transducer (IDT). The IDT and the piezoelectric plate are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic mode within the piezoelectric plate. The acoustic Bragg reflector is configured to reflect the shear primary acoustic mode. An interposer has a second plurality of contact pads on a back surface. A seal connects a perimeter of the piezoelectric plate to a perimeter of the interposer. Each contact pad of the first plurality of contact pads is directly connected to a respective contact pad of the second plurality of contact pads.

Abstract: An acoustic wave device includes a piezoelectric layer and first and second electrodes. The first and second electrodes face each other in a direction crossing a thickness direction of the piezoelectric layer. The acoustic wave device utilizes a bulk wave of a thickness-shear primary mode. The material of the piezoelectric layer is lithium niobate or lithium tantalate. The first and second electrodes include aluminum layers, respectively, on the piezoelectric layer. An orientation direction of a crystal of each of the aluminum layers is a direction orthogonal or substantially orthogonal to a second principal surface on the piezoelectric layer side of each of the aluminum layers.

Abstract: A piezoelectric transducer is provided herein, comprising a three-dimensional structure made of a plurality of peptides, the peptides being self-assembling and the structure being piezoelectric, wherein at least a portion, or each, of said plurality of peptides comprises peptides of 2 to 10 amino acid residues, provided that the plurality of peptides is not consisted of a plurality of Phe-Phe dipeptides. Further described herein are peptides having an amino acid sequence Hyp-Phe-Phe, Boc-Dip-Dip, (L)Trp-(D)Trp or (D)Trp-(L)Trp, as well as three-dimensional structures comprising such peptides.

Abstract: A resonator package and a method of manufacturing the same are provided. The method of manufacturing a resonator package involves etching a lower electrode with a hardmask, in which only a portion of a thickness of the lower electrode is etched to shape the lower electrode.

Abstract: A piezoelectric valve including an actuator that drives a valve body; a valve seat plate including a valve seat that is adapted to be positioned in contact with and away from the valve body, and a discharge passage; and a body case that houses the valve seat plate, in which the actuator includes a proximal portion fixed to the valve seat plate, a piezoelectric element having one end portion connected to an attachment face of the proximal portion and extending in a first longitudinal direction, a support portion integrally formed with the proximal portion, the support portion being arranged side-by-side with the piezoelectric element and extending in a second longitudinal direction crossing the first longitudinal direction, an operating portion connected to another end portion of the piezoelectric element and to a distal end portion of the support portion.

Abstract: An ultrasonic transducer device comprises a piezoelectric micromachined ultrasonic transducer (PMUT), a transmitter with first and second differential outputs, and a controller. The PMUT includes a membrane layer. A bottom electrode layer, comprising a first bottom electrode and a second bottom electrode, is disposed above the membrane layer. The piezoelectric layer is disposed above the bottom electrode layer. The top electrode layer is disposed above the piezoelectric layer and comprises a segmented center electrode disposed above a center of the membrane layer and a segmented outer electrode spaced apart from the segmented center electrode. The controller, responsive to the PMUT being placed in a transmit mode, is configured to couple the first and second segments of the bottom electrode layer with ground, couple the first output of the transmitter with the segments of the segmented center electrode, and couple the second output with the segments of the segmented outer electrode.

Abstract: A solid electrolyte according to the present disclosure is represented by the following compositional formula (1). Li7-2x-zLa3(Zr2-x-zWxMz)O12??(1) In the formula (1), x and z satisfy 0.10?x?0.60 and 0.00<z?0.25, and M is at least one type of element selected from the group consisting of Nb, Ta, and Sb.

Abstract: Embodiments may relate to a die such as an acoustic wave resonator (AWR) die. The die may include a first filter and a second filter in the die body. The die may further include an electromagnetic interference (EMI) structure that surrounds at least one of the filters. Other embodiments may be described or claimed.

Abstract: A resonator is provided that includes a vibration member that includes a substrate, a metal layer formed along one of main surfaces of the substrate, and a piezoelectric thin film disposed between the substrate and the metal layer. The vibration member vibrates such that a main vibration is a contour vibration. Moreover, a frame surrounds at least a portion of the vibration member, and a support unit connects the vibration member to the frame. The vibration member includes depressed portions on or above the one of main surfaces where the piezoelectric thin film is removed.

Abstract: A microelectromechanical resonator, including a support structure, a resonator element suspended to the support structure, the resonator element including a plurality of sub-elements, and an actuator for exciting the resonator element into a resonance mode. The sub-elements are dimensioned such that they are dividable in one direction into one or more fundamental elements having an aspect ratio different from 1 so that each of the fundamental elements supports a fundamental resonance mode, which together define a compound resonance mode of the sub-element. The sub-elements are further coupled to each other by connection elements and positioned with respect to each other such that the fundamental elements are in a rectangular array configuration, wherein each fundamental element occupies a single array position, and at least one array position of the array configuration is free from fundamental elements.

Abstract: Acoustic resonator devices, filers, and methods. An acoustic resonator includes a substrate and a piezoelectric plate, a portion of the piezoelectric plate being a diaphragm spanning a cavity in the substrate. A conductor pattern on a front surface of the piezoelectric plate includes interleaved interdigital transducer (IDT) fingers connected alternately to first and second busbars. The interleaved IDT fingers are on the diaphragm, and the interleaved IDT fingers include at least a first pair of interleaved spiral IDT fingers.

Abstract: In one example, a method of forming a bulk acoustic wave (BAW) resonator comprises: forming an electrode on at least one of a semiconductor substrate, a sacrificial layer, or an acoustic reflector; and forming a piezoelectric layer on the electrode, the piezoelectric layer having a convex surface.

Abstract: A fabrication method of a surface acoustic wave (SAW) filter includes obtaining a piezoelectric substrate, forming a back electrode on a first portion of the piezoelectric substrate, forming a first dielectric layer on the first portion of the piezoelectric substrate, forming a trench in the first dielectric layer, forming a second dielectric layer on the first dielectric layer formed with the trench, forming a third dielectric layer on the second dielectric layer, removing a second portion of the piezoelectric substrate to obtain a piezoelectric layer, forming an interdigital transducer (IDT) on the piezoelectric layer, and etching and releasing a portion of the first dielectric layer surrounded by the trench to form a cavity below the back electrode.

Abstract: An ultrasonic device includes a substrate having a plurality of opening parts and a wall, a vibrating plate closing the opening parts, and vibrators provided to the vibrating plate, wherein the plurality of opening parts includes a first opening part, a second opening part adjacent to the first opening part via a first wall, and a third opening part adjacent to the first opening part via a second wall, a first vibrating section closing the first opening part and the vibrator constitute a first ultrasonic transmitter, a second vibrating section closing the second opening part and the vibrator constitute an ultrasonic receiver, a third vibrating section closing the third opening part and the vibrator constitute a second ultrasonic transmitter, and the wall width of the first wall is larger than the wall width of the second wall.

Abstract: Bulk acoustic wave (BAW) resonators and particularly top electrodes with step arrangements for BAW resonators are disclosed. Top electrodes on piezoelectric layers are disclosed that include a border (BO) region with a dual-step arrangement where an inner step and an outer step are formed with increasing heights toward peripheral edges of the top electrode. Dielectric spacer layers may be provided between the outer steps and the piezoelectric layer. Passivation layers are disclosed that extend over the top electrode either to peripheral edges of the piezoelectric layer or that are inset from peripheral edges of the piezoelectric layer. Piezoelectric layers may be arranged with reduced thickness portions in areas that are uncovered by top electrodes. BAW resonators as disclosed herein are provided with high quality factors and suppression of spurious modes while also providing weakened BO modes that are shifted farther away from passbands of such BAW resonators.

Abstract: A dual channel detector. The first channel includes a first sensor and the second channel includes a second sensor, which are deposited on a substrate. The first and second sensors measure the same physical quantity, but output different measurement signals. The sensors are connected to evaluation units via contact points.

Abstract: Disclosed in an ultrasonic probe for obtaining an ultrasonic image.

Abstract: Acoustic resonator devices, filters, and methods. An acoustic resonator includes a substrate and a piezoelectric plate, a portion of the piezoelectric plate being a diaphragm spanning a cavity in the substrate. A conductor pattern on a front surface of the piezoelectric plate includes concentric interleaved interdigital transducer (IDT) fingers connected alternately to first and second busbars. The IDT fingers are on the diaphragm.

Abstract: A bulk acoustic resonator includes a first electrode disposed on an upper side of a substrate, a piezoelectric layer disposed on an upper surface of the first electrode, and a second electrode disposed on an upper surface of the piezoelectric layer, wherein an upper surface of at least one of the first electrode and the second electrode has a recess region, wherein a depth of the recess region is D, a width of the recess region is W, and a resonance frequency is F, and ln is a natural logarithm, and wherein [{ln(D*W)}/(?0.59*F)] is [[ln{0.008 (?m)2}]/{?0.59*(3.5 GHz)}] or more and [[ln{0.022 (?m)2}]/{?0.59*(3.5 GHz)}] or less.

Abstract: A piezoelectric device comprises at least one piezoelectric composite layer P inserted between two conductive composite layers E, each layer E forming an electrode, characterized in that: the layer P is a rubber composition containing more than 50 parts by weight per hundred parts by weight rubber, phr, of diene elastomer, a cross-linking system and at least 5 vol. %, in relation to the total volume of the rubber composition, of piezoelectric inorganic charges; and each layer E is a rubber composition containing at least 50 phr of diene elastomer, a cross-linking system, and conductive charges. A method for producing the device and a tire comprising the device are also disclosed.

Abstract: An acoustic wave device in which a cavity defining an acoustic reflector is formed on a first main surface side of a substrate, an excitation portion is structured above the cavity in a manner that a first electrode, a piezoelectric thin film, and a second electrode are laminated, and a periodic pattern is provided in a normal direction of a side of the excitation portion on at least one of a first extraction electrode and a second extraction electrode.

Abstract: An apparatus is disclosed for site-selective piezoelectric-layer trimming. The apparatus includes at least one surface-acoustic-wave filter with an electrode structure and a piezoelectric layer. The electrode structure has multiple gaps. The piezoelectric layer has a planar surface defined by a first (X) axis and a second (Y) axis that is perpendicular to the first (X) axis. The piezoelectric layer is configured to propagate an acoustic wave along the first (X) axis. The piezoelectric layer includes a first portion that supports the electrode structure and a second portion that is exposed by the multiple gaps of the electrode structure. The second portion has different heights across the second (Y) axis. The different heights are defined with respect to a third (Z) axis that is substantially normal to the planar surface.

Abstract: A vibrator, a vibrating element and a method for producing the vibrating element may include vibrating piece having a central portion and a peripheral portion. The vibrator, the vibrating element and the method may further include a pair of excitation electrodes provided on a first side and a second side of a main surface of the central portion. The vibrator, the vibrating element and the method may further include a pair of connection electrodes provided on the peripheral portion and electrically connected to the pair of excitation electrodes. The vibrator, the vibrating element and the method may further include a substrate configured to be connected to the pair of connection electrodes via an electrically-conductive holding member interposed therebetween and configured to support the vibration element in an excitable manner.

Abstract: A microfluidic device for continuous ejection of fluids includes: a semiconductor body that laterally delimits chambers; an intermediate structure which forms membranes each delimiting a top of a corresponding chamber; and a nozzle body which overlies the intermediate structure. The device includes, for each chamber: a corresponding piezoelectric actuator; a supply channel which traverses the intermediate structure and communicates with the chamber; and a nozzle which traverses the nozzle body and communicates with the supply channel. Each actuator is configured to operate i) in a resting condition such that the pressure of a fluid within the corresponding chamber causes the fluid to pass through the supply channel and become ejected from the nozzle as a continuous stream, and ii) in an active condition, where it causes a deformation of the corresponding membrane and a consequent variation of the pressure of the fluid, causing a temporary interruption of the continuous stream.

Abstract: Provided is a bulk acoustic wave resonator. The bulk acoustic wave resonator includes an upper electrode, a piezoelectric layer and a lower electrode. The piezoelectric layer is disposed between the upper electrode and the lower electrode. At least one boundary of an orthogonal projection of the piezoelectric layer on the lower electrode includes a plurality of sawtooth structures.

Abstract: A resonator device includes: a base; a resonator element that includes a resonator substrate and an electrode; a conductive layer that is disposed on the base; a metal bump that is disposed between the conductive layer and the resonator element, and that electrically couples the conductive layer and the electrode while bonding the conductive layer and the resonator element; and at least one of a first low elastic modulus layer that is interposed between the base and the conductive layer, that overlaps the metal bump in a plan view of the base, and that has an elastic modulus smaller than that of the metal bump, and a second low elastic modulus layer that is interposed between the resonator substrate and the electrode, that overlaps the metal bump in the plan view of the base, and that has an elastic modulus smaller than that of the metal bump.

Abstract: An active suspension control system for a vehicle includes a mathematical model based on a modal expansion of the vehicle. Model parameters of the vehicle can be extracted from the modal expansion using sensor data generated on the vehicle, e.g., on demand and/or in real time. The model parameters and the modal expansion can be used to determine a vehicle state, predict future vehicle states, and control aspects of an active suspension system based on the predicted future vehicle states. The model parameters may also be used to update the mathematical model, e.g., to account for component wear over time, and/or to detect anomalies or defects in the active suspension system.

Abstract: A resonator, a filter and a duplexer, which relate to the technical field of resonators. The resonator includes: a substrate, and a lower electrode layer, a piezoelectric layer and an upper electrode layer, which are sequentially formed on the substrate, wherein an acoustic reflection structure is formed on a surface of the substrate that is close to the lower electrode layer, and an overlapping region of the acoustic reflection structure, the lower electrode layer, the piezoelectric layer and the upper electrode layer along a stacking direction forms a resonant region; and in the resonant region, the surface, which is away from the substrate, of at least one of the lower electrode layer, the piezoelectric layer and the upper electrode layer is etched to form an etched region, the depth of the etched region is less than the thickness of an etched layer, and the area of the etched region is less than the area of the resonant region.

Abstract: A piezoelectric element includes, in sequence, a substrate, a lower electrode layer, a growth control layer, a piezoelectric layer including a perovskite-type oxide containing lead as a main component of an A site, and an upper electrode layer. The growth control layer includes a metal oxide represented by MdN1?dOe, where M is one or more metal elements capable of substituting for the A site of the perovskite-type oxide. When the electronegativity of M is X, 1.41X?1.05?d?A1·exp(?X/t1)+y0, where A1=1.68×1012, t1=0.0306, and y0=0.59958. The perovskite-type oxide is represented by (Pba1?a2)(Zrb1Tib2?b3)Oc, where 0.5<a1/(b1+b2+b3)<1.07.

Abstract: A quartz crystal resonator includes a quartz crystal resonator element, a thermistor, and a package base having a first principal surface and a second principal surface having an opposed surface relationship with each other, the quartz crystal resonator element is mounted on the first principal surface side, the thermistor is housed in a recessed section of the second principal surface side of the package base, a plurality of electrode terminals connected to the quartz crystal resonator element or the thermistor is disposed on the second principal surface side of the package base, and a distance in a first direction perpendicular to the first principal surface from a mounting surface of the electrode terminals to the thermistor is equal to or longer than 0.05 mm.

Abstract: An electrode pair is provided including a first electrode and a second electrode. Each of the first electrode and the second electrode have an outer surface, an inner surface, a first end, a second end, and a lead extending outwardly from the first end. The lead has a first width at the first end. The second end of at least one of the first electrode and the second electrode have a recess formed therein having a first terminus and a second terminus. A second width extends between the first terminus and the second terminus of the recess. The recess is defined by a saw-tooth pattern. When the first electrode is positioned on the second electrode, the recess of the at least one of the first electrode is adjacent the lead of the other electrode.

Abstract: This application provides a bulk acoustic wave resonator and a bulk acoustic wave filter, and relates to the technical field of filters. The bulk acoustic wave resonator includes a substrate, and a bottom electrode, a piezoelectric layer, a top electrode which are sequentially stacked on the substrate, and an outline of an orthographic projection of the top electrode on the substrate is formed by four curves which are end-to-end connected. Arc transition is set at a joint of every two adjacent curves, and every two curves arranged in a spaced manner are not parallel. Accordingly, reliability of devices can be effectively improved, meanwhile, parasitic resonance amplitude can be effectively restrained, a Q value is increased, and thus device properties are improved.

Abstract: Acoustic resonator devices and acoustic filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm, and a conductor pattern on the front surface, the conductor pattern comprising an interdigital transducer (IDT), interleaved fingers of the IDT on the diaphragm. A ratio of a mark of the interleaved fingers to a pitch of the interleaved fingers is greater than or equal to 0.12 and less than or equal to 0.3. A thickness of the interleaved fingers is greater than or equal to 0.85 times a thickness of the piezoelectric plate and less than or equal to 2.5 times the thickness of the piezoelectric plate.

Abstract: This invention relates to a multilayer ceramic capacitor produced by alternatively stacking the ceramic dielectric layers and internal electrodes mainly comprise base metals. The present dielectric ceramic composition having a main component with a perovskite structure ABO3 formula of: (KxNayLizA1-x-y-z)m(NbuTav)O3 wherein: A, B, x, y, z, u, v, w, m, u, v and w are defined further. The dielectric ceramic composition further contains: a first accessory ingredient composes at least one selected from the rare-earth compounds; a second accessory ingredient composes at least one selected from transition metal compounds; and a third accessory ingredient.

Abstract: A vibrator device includes a vibrating body having obverse and reverse principal surfaces and a side surface connecting the obverse and reverse principal surfaces to each other, a package configured to house the vibrating body, and a bonding material configured to fix the vibrating body to the package, wherein the vibrating body has a coupling part including a recess recessed from the side surface toward a center of the principal surfaces, and a protrusion protruding from a side surface of the recess, the protrusion is one of breaking-off parts with which a plurality of the vibrating bodies is broken off from a wafer to which the plurality of the vibrating bodies is coupled, and the bonding material has contact with a side surface of the protrusion in the recess.

Abstract: Disclosed are a fingerprint identification structure, a driving method thereof and an electronic device. The fingerprint identification structure includes: a driving electrode layer; a piezoelectric material layer; a receiving electrode layer, which includes M receiving electrodes; an auxiliary driving electrode layer, which is located at the side of the piezoelectric material layer away from the receiving electrode layer, and is arranged in a layer different from the driving electrode layer; and a first insulating layer, the auxiliary driving electrode layer includes N auxiliary driving electrodes; the N driving electrodes and the N auxiliary driving electrodes are alternately arranged; and the orthographic projection, on the piezoelectric material layer, of an i-th auxiliary driving electrode overlaps with an interval between the orthographic projections, on the piezoelectric material layer, of an i-th driving electrode and an (i+1)-th driving electrode.

Abstract: The invention relates to a device comprising a body and a set of vibration absorbers mounted on the body, each absorber being movable relative to the body between a first position and a second position, each absorber being capable of oscillating relative to the body between its first and second positions, a first natural frequency being defined for each absorber, at least one absorber having a first natural frequency different from the first natural frequency of another absorber. Each absorber comprises at least one deformation part capable of deforming as the vibration absorber oscillates between its first position and its second position, the deformation part having at least two faces configured to rub against each other during the deformation of the deformation part.

Abstract: A method for producing an at least partially transparent device is provided, including producing, on a first substrate, first and second separation layers one against the other; producing, on the second separation layer, an at least partially transparent functional layer; making the functional layer integral with a second at least partially transparent substrate; forming a mechanical separation at an interface between the separation layers; removing the second separation layer; producing a first at least partially transparent electrode layer on the functional layer; where the materials of the stack are chosen such that the interface between the separation layers corresponds to that, among all the interfaces of the stack, having the lowest adherence force.

Abstract: Embodiments described herein may provide a surface acoustic wave (SAW) device, methods of fabricating the SAW device, and a system incorporating the SAW device. The SAW device may include a piezoelectric substrate and individual resonators may be formed by a plurality of electrodes on the surface of the piezoelectric substrate. A dielectric layer having a positive thermal coefficient of frequency (TCF) may be formed on each of the plurality of electrodes. In various embodiments, temperature compensation may be achieved by providing more or less of the dielectric layer on at least one resonator than on the other resonators based on a configuration of the resonators. In various embodiments, temperature compensation may be achieved by providing at least one resonator with a different duty factor than the other resonators based on a configuration of the resonators.

Abstract: A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.

Abstract: A resonance element supported by a bearing structure includes a crystal chip and an excitation electrode. The crystal chip includes a main surface having a support surface portion being in contact with the bearing structure. The excitation electrode is disposed on the main surface, has an electrode area, and includes an electrode indentation boundary partly encompassing the support surface portion. The electrode indentation boundary has a first boundary end and a second boundary end being opposite to the first boundary end. The electrode indentation boundary and a reference line segment defined by the first and the second boundary ends form an electrode indentation region having an indentation area. A ratio of the indentation area to the electrode area ranges from 0.05 to 0.2.