Abstract: Disclosed herein is a method of manufacturing an inertial sensor. The method of manufacturing an inertial sensor 100 includes (A) applying a polymer 120 to a base substrate 110, (B) patterning the polymer 120 so as to form an opening part 125 in the polymer 120, (C) completing a cap 130 by forming a cavity 115 on the base substrate 110 exposed fro the opening part 125 through an etching process in a thickness direction, and (D) bonding the cap 130 to a device substrate 140 by using a polymer 120, whereby the polymer 120 is applied to the base substrate 110 in a constant thickness D3, such that the cap 130 may be easily bonded to the device substrate 140 by using the polymer 120.

Abstract: A planar integrated MEMS device has a piezoelectric element on a dielectric isolation layer over a flexible element attached to a proof mass. The piezoelectric element contains a ferroelectric element with a perovskite structure formed over an isolation dielectric. At least two electrodes are formed on the ferroelectric element. An upper hydrogen barrier is formed over the piezoelectric element. Front side singulation trenches are formed at a periphery of the MEMS device extending into the semiconductor substrate. A DRIE process removes material from the bottom side of the substrate to form the flexible element, removes material from the substrate under the front side singulation trenches, and forms the proof mass from substrate material. The piezoelectric element overlaps the flexible element.

Abstract: An apparatus for generating electric energy comprises a vibration plate, a supporting board, at least one side-wall unit and at least one piezoelectric substrate having a first- and a second end surfaces covered with a first- and a second electrodes, respectively. They all together form at least one cavity resonator. If a sound pressure from the outside arrives at the vibration plate, an acoustic vibration is excited in the vibration plate, and thereby a resonance vibration is induced in the cavity resonator. In this time, the piezoelectric substrate responds collectively to the resonance vibration. Thus, a resonance energy occurred in the cavity resonator is converted into an electric energy, which is delivered through the first- and second electrodes.

Abstract: A transverse acoustic wave resonator includes a base, a resonator component, a number of driving electrodes fixed to the base and a number of fixing portions connecting the base and the resonator component. The resonator component is suspended above a top surface of the base and is perpendicular to the base. The driving electrodes are coupling to side surfaces of the resonator component. The resonator component is formed in a shape of an essential regular polygon. The driving electrodes and the resonator component jointly form an electromechanical coupling system for converting capacitance into electrostatic force. Besides, a capacitive-type transverse extension acoustic wave silicon oscillator includes the transverse acoustic wave resonator and a method of fabricating the transverse acoustic wave resonator are also disclosed.

Abstract: A variety of micromachined structures are disclosed for use in DC-tunable ultrasound transducers.

Abstract: A dual in-situ mixing approach for extended tuning range of resonators. In one embodiment, a dual in-situ mixing device tunes an input radio-frequency (RF) signal using a first mixer, a resonator body, and a second mixer. In one embodiment, the first mixer is coupled to receive the input RF signal and a local oscillator signal. The resonator body receives the output of the first mixer, and the second mixer is coupled to receive the output of the resonator body and the local oscillator signal to provide a tuned output RF signal as a function of the frequency of local oscillator signal.

Abstract: An electromechanical generator comprising an electromechanical device for converting mechanical vibrational energy into electrical energy, the electromechanical device being a velocity damped resonator having a damping coefficient and a resonant frequency, a power detector for detecting the output electrical power from the electromechanical device, a controller, and a damping coefficient adjuster for adjusting the damping coefficient of the electromechanical device, the controller being arranged to control the damping coefficient adjuster in response to the output electrical power detected by the power detector.

Abstract: Piezoelectric vibrating pieces are disclosed having selectively roughened surfaces. An exemplary piece is made of a piezoelectric material configured as a piezoelectric substrate. The piece also includes at least one excitation electrode and at least one extraction electrode. The substrate has opposing main surfaces initially having low surface roughness. At least one main surface is formed in a mesa or reverse mesa manner, wherein the central region has a different thickness than the peripheral region. The central region has relatively low surface roughness (irregular unevenness), while the peripheral region has relatively high surface roughness. The excitation electrode is formed on the central region (mesa or reverse mesa) while the extraction electrode (connected to the excitation electrode) is formed on the peripheral region.

Abstract: A planar integrated MEMS device has a piezoelectric element on a dielectric isolation layer over a flexible element attached to a proof mass. The piezoelectric element contains a ferroelectric element with a perovskite structure formed over an isolation dielectric. At least two electrodes are formed on the ferroelectric element. An upper hydrogen barrier is formed over the piezoelectric element. Front side singulation trenches are formed at a periphery of the MEMS device extending into the semiconductor substrate. A DRIE process removes material from the bottom side of the substrate to form the flexible element, removes material from the substrate under the front side singulation trenches, and forms the proof mass from substrate material. The piezoelectric element overlaps the flexible element.

Abstract: A crystalline semiconductor resonator device comprises two matched resonators which are aligned differently with respect to the crystal structure of the crystalline semiconductor. The resonators each comprise a portion of a material having a different temperature dependency of the Young's modulus to the temperature dependency of the Young's modulus of the crystalline semiconductor material. In this way, the suspension springs for the resonators have different properties, which influence the resonant frequency. The resonant frequency ratios between the first and second resonators at a calibration temperature and an operation temperature are measured. A frequency of one (or both) of the resonators at the operation temperature can then be derived which takes into account the temperature dependency of the one of the resonators.

Abstract: A method of protecting a resonating sensor is described. The protected resonating sensor may include at least one passive ultrasonically excitable resonating sensor unit. Each sensor unit has one or more vibratable members having a resonating frequency that varies as a function of a physical variable in a measurement environment. The sensor is protected by forming one or more protective chambers defined between a compliant member and the vibratable member(s). A substantially non-compressible medium is disposed within the protective chamber(s). The compliant member has a first side that may be exposed to a measurement environment and a second side that may be exposed to the substantially non-compressible medium. The substantially non-compressible medium may be a liquid or gel and is in contact with the vibratable member(s). When the medium is a liquid, the chamber is sealed. When the medium is a gel, the chamber may be sealed or non-sealed.

Abstract: Periodic signal generators include an oscillator circuit, which is configured to generate a first periodic signal at an output thereof, and a piezoelectric-based microelectromechanical resonator. The resonator is configured to generate a second periodic signal at a first electrode thereof, which is electrically coupled to the oscillator circuit. A variable impedance circuit is provided, which is electrically coupled to a second electrode of the piezoelectric-based microelectromechanical resonator. The variable impedance circuit is configured to passively modify a frequency of the second periodic signal by changing an induced electromechanical stiffness in at least a portion of the piezoelectric-based microelectromechanical resonator.

Abstract: An acoustic wave device includes a main resonator and a sub resonator each having a substrate, a lower electrode provided on the substrate, a piezoelectric film provided on the lower electrode, and an upper electrode provided on an upper side of the piezoelectric film. The sub resonator has a mass addition film on the upper electrode in a resonance area in which the upper electrode and the lower electrode face each other. At least one of the main resonator and the sub resonator is provided with a frequency control film on an upper side of the resonance area, and the frequency control film has a weight per unit area smaller than a weight of the mass addition film per unit area.

Abstract: In a representative embodiment, a bulk acoustic wave (BAW) resonator structure comprises: a first electrode disposed over a substrate; a first piezoelectric layer disposed over the first electrode; a second electrode disposed over the first piezoelectric layer, wherein c-axis orientations of crystals of the first piezoelectric layer are substantially aligned with one another; a second piezoelectric layer disposed over the second electrode; a non-piezoelectric layer; and a third electrode disposed over the second piezoelectric layer.

Abstract: An acoustic transducer array element includes a plurality of individual or transducer assemblies or “drivers” which are combined in a closely spaced geometry to form the array element. The respective transducer assemblies within each array element are acoustically coupled with each other. The invention utilizes such mutual coupling between the closely spaced transducers assemblies to provide improved acoustic performance.

Abstract: In a representative embodiment, a bulk acoustic wave (BAW) resonator structure comprises: a first electrode disposed over a substrate; a first piezoelectric layer disposed over the first electrode; a second electrode disposed over the first piezoelectric layer, wherein c-axis orientations of crystals of the first piezoelectric layer are substantially aligned with one another; a second piezoelectric layer disposed over the second electrode; a non-piezoelectric layer; and a third electrode disposed over the second piezoelectric layer.

Abstract: A method for tuning a resonant frequency of a piezoelectric component is disclosed. The piezoelectric component includes a transducer extending in three spatial directions. The resonant frequency depends on an extension in at least one of the spatial directions and/or on a material-dependent elasticity modulus. The transducer includes a layered structure with at least two first electrodes and at least one second electrode, which is disposed between the two first electrodes. In the method, a DC voltage is applied to at least one of the at least two first electrodes and the at least one second electrode, so that a change of the resonant frequency results due to a change to the extension in the one spatial direction and the elasticity modulus. A control voltage with an excitation frequency is applied, the excitation frequency substantially corresponding to the modified resonant frequency. This generates a vibration of the piezoelectric component.

Abstract: This disclosure provides implementations of electromechanical systems resonator structures, devices, apparatus, systems, and related processes. In one aspect, resonator apparatus includes a first conductive layer including a first electrode and a second electrode. The first electrode is coupled to receive a first input signal, and the second electrode is coupled to provide a first output signal. A piezoelectric layer includes a piezoelectric material. The piezoelectric layer has a first side and a second side opposite the first side. The first side is proximate the first conductive layer, and the second side is electrically isolated from ground. In some examples, the second side of the piezoelectric layer can be exposed and/or electrically de-coupled from one or more components.

Abstract: A piezoelectric generator includes a fixing part; a cantilever formed at a front edge of the fixing part; a weight part formed at a front end of the cantilever; a centroid adjustment part by which a position of a centroid of the weight part is adjusted; and a piezoelectric generating cell formed on top of the cantilever.

Abstract: The present invention is a piezoelectric crystal oscillator using parametric amplification to enhance the Q. Parametric amplification is accomplished by driving the same region of the crystal as used for the oscillator with an overtone of the crystal resonator.

Abstract: A detection sensor (10) includes: plural beam-like resonators (30A, 30B), a vibration characteristic of which changes according to adsorption or sticking of a substance having a mass and one end of each of which is fixed; a driving unit (40) that vibrates the resonators; and a detecting unit (40) that detects a change in the vibration in the resonators to detect the substance. The plural resonators have lengths different from one another. When the length of an arbitrary resonator is represented as L, a difference ?L between the length L and the length of the other resonators is set to satisfy the following condition: 2(?L/L)>1/Q (Q represents a Q factor of the resonators). The driving unit vibrates the respective plural resonators at frequencies corresponding to resonant frequencies of the resonators.

Abstract: To provide an elastic wave device that is small sized and in which a frequency fluctuation due to a change with time hardly occurs, and an electronic component using the above elastic wave device. A trapping energy mode portion 2 provided in an elastic wave waveguide 10 made of an elastic body material excites a second elastic wave being an elastic wave in an energy trapping mode by a specific frequency component included in a first elastic wave being an elastic wave in a first or higher-order propagation mode propagated from a first propagation mode portion 4, and a cutoff portion 3 provided in a peripheral region of the trapping energy mode portion 2 has a cutoff frequency being a frequency higher than that of the second elastic wave. A second propagation mode portion mode-converts the second elastic wave leaked through the cutoff portion to a third elastic wave being the elastic wave in the propagation mode to propagate the third elastic wave.

Abstract: An arrangement consisting of a piezoactuator and a printed circuit board that are connected by at least one adhesive connection, with at least one electrical connection created by an electrically conductive adhesive between a first connection contact on the printed circuit board and between a second connection contact on the piezoactuator, whereby the connection contacts face in the same direction and the adhesive connection takes place through an opening in one of the components.

Abstract: A micro-electro-mechanical device including a substrate with a main surface, a piezoelectric actuator with a first side mechanically coupled to the substrate, an elastic member with a first end mechanically coupled to the substrate, and a transfer member mechanically coupling a second side of the piezoelectric actuator to the elastic member. The piezoelectric actuator is positioned lateral to an unfixed region of the elastic member. The method includes applying a voltage to a piezoelectric actuator altering the piezoelectric actuator's dimension vertical to the main surface of the substrate; and mechanically transferring the alteration to a coupling point of an elastic member.

Abstract: The present invention discloses a physical/biochemical sensor using a multisized piezoelectric microcantilever resonator array which enables to quantitatively and simultaneously analyze a mass loading effect and a surface stress change effect and a manufacturing method thereof. In the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array, a plurality of piezoelectric micro-cantilever resonators having different sizes is arrayed so as to quantitatively and discriminately analyze a surface stress change as well as a sensor surface mass change induced by an adsorbed sensing-target material occurring in a sensing process. Thus, the mass loading effect and the surface stress change effect can be quantitatively and simultaneously analyzed.

Abstract: An X-axis driving mechanism section as one of driving sources of a driving apparatus including: a transducer for generating an elliptical vibration on a driving section in response to application of a predetermined frequency voltage signal; a bottom case having a holding section for holding the transducer; a pressing mechanism arranged on the bottom case to press the driving section of the transducer; and a rod relatively driven by the elliptical vibration of the transducer while being pressed by the pressing mechanism and with a moving direction being restricted by a guiding section of the holding member; wherein a weight is fixed to an end portion of the rod. The X-axis driving mechanism section constitutes the driving apparatus which is small and provides a large driving force, is capable of stable driving with higher efficiency without producing audible noise, and can retain the rod position and has high responsiveness with high accuracy.

Abstract: A piezoelectric thin film resonant element includes a resonant portion having a laminate structure made up of a lower electrode, an upper electrode and a piezoelectric film arranged between these two electrodes. The lower electrode has an ellipsoidal plan-view shape and an outer circumference formed with an inclined portion inclined at an angle (about 30° for example) lying within a range of 25° through 55°. The upper electrode has an ellipsoidal plan-view shape. An additional film is provided on the upper electrode at a portion corresponding to the inclined portion of the lower electrode.

Abstract: A MEMS component includes a chip that has a rear side having a low roughness of less than one tenth of the wavelength at the center frequency of an acoustic wave propagating in the component. Metallic structures for scattering bulk acoustic waves are provided on the rear side of the chip and a material of the metallic structures is acoustically matched to a material of the chip.

Abstract: A piezoelectric sensor having a plurality of electrodes deposited on a single surface of the dielectric medium is generally provided. The plurality of electrodes can define a plurality of square-shaped electrodes forming a grid on the first surface of the dielectric medium while the second electrode defines a continuous electrode. An electrode border surrounding the plurality of electrodes can be deposited on the first surface of the dielectric medium. Alternatively, the plurality of electrodes can define column-shaped electrodes, while the second electrode defines a plurality of row-shaped electrodes separated by etchings. The direction of orientation of each column-shaped electrode and the direction of orientation of each row-shaped electrode can be substantially perpendicular. A method of making a piezoelectric sensor is also provided.

Abstract: A system and a retrofit kit for removing debris from a surface of a material. At least one vibration subunit is provided which is either embedded within or operatively connected to a back surface of the material. The vibration subunits are capable of converting a driving energy to a vibrating mechanical output energy which is coupled to the material. At least one external energy source is provided which is operatively connected to the vibration subunits. The external energy source is capable of providing the driving energy to the vibration subunits. The vibrating mechanical energy is capable of causing debris to be removed from the surface of the material.

Abstract: Patterns detection to input data containing a plurality of transactions, each transaction having at least one item, is carried out in the following way. Filter conditions for interesting patterns are received, and a first wet of filter conditions applicable in connection with generation of candidate patterns is determined.

Abstract: A vibrator element includes: a base section formed on a plane including a first direction and a second direction perpendicular to the first direction; and a vibrating arm extending from the base section in the first direction, wherein the vibrating arm flexurally vibrates in a normal direction of the plane, and has a first surface one of compressed and extended due to the flexural vibration and a second surface one of extended when the first surface is compressed and compressed when the first surface is extended, the first surface is provided with a first mass section, and the second surface is provided with a second mass section, and at least one of the first mass section and the second mass section has a portion, which fails to be opposed to the other of the first mass section and the second mass section in a plan view in the normal direction.

Abstract: A piezoelectric component with a body in which electrically connected transducer elements are realized is disclosed. The transducer elements are separated from each other by an essentially field-free neutral region of the body. A first transducer element has electrically connected first electrodes, and a second transducer element has electrically connected second electrodes. In addition, at least one third electrode, which is arranged in the first and second transducer element is provided. At least three of the first and third electrodes are arranged in an alternating sequence. At least three of the second and third electrodes are arranged in an alternating sequence. The neutral area is perpendicular to the planes in which the electrodes are arranged.

Abstract: An optical apparatus includes a vibrated member and a piezoelectric element. The piezoelectric element vibrates the vibrated member at a predetermined vibration mode to remove a foreign substance adhered to a surface of the vibrated member. A drive electrode, a first vibration detection electrode and a second vibration detection electrode are provided on a first face of the piezoelectric element, and a ground electrode is provided on a second face of the piezoelectric element. The first vibration detection electrode and the second vibration detection electrode have an axis-symmetrical shape, and are arranged on the first face of piezoelectric element so as to be symmetrical with respect to an axis along which a predetermined vibration node occurs when the vibrated member vibrates at the predetermined vibration mode.

Abstract: A mechanical oscillator has components with dimensions in a sub-micron range to produce resonance mode oscillations in a gigahertz range. A major element is coupled to a minor, sub-micron element to produce large amplitude gigahertz frequency oscillation that is detected with readily available techniques. The mechanical structure can be formed according to a number of geometries including beams and rings and is excited with electrostatic, magnetic and thermal related forces, as well as other excitation techniques. The mechanical structure can be arranged in arrays for applications such as amplification and mixing and is less sensitive to shock and radiative environments than electrical or optical counterparts.

Abstract: A dual in-situ mixing approach for extended tuning range of resonators. In one embodiment, a dual in-situ mixing device tunes an input radio-frequency (RF) signal using a first mixer, a resonator body, and a second mixer. In one embodiment, the first mixer is coupled to receive the input RF signal and a local oscillator signal. The resonator body receives the output of the first mixer, and the second mixer is coupled to receive the output of the resonator body and the local oscillator signal to provide a tuned output RF signal as a function of the frequency of local oscillator signal.

Abstract: In a method for manufacturing at least one mechanical-electrical energy conversion system including multiple individual parts, and a mechanical-electrical energy conversion, multiple different individual parts are positioned in an assembly device and joined in joining areas assigned to the individual parts in the assembly device, the individual parts including at least one piezoelectric element, one support structure and one seismic mass.

Abstract: A method for generating power in a wellbore includes moving an actuator; inducing an oscillating stress on a piezoelectric component with the actuator; and generating a voltage with the piezoelectric component in response to the induced stress on the piezoelectric component.

Abstract: A composite acoustic wave device provides improved protection from environmental factors while maintaining high electrical characteristics and dynamic range is provided. The device comprises a rigid protector plate having high quality acoustical characteristics and a thickness which is a multiple of half wavelength of the resonant frequency. A piezoelectric plate is coupled to the protector plate, is supported therefrom, and forms an energy interface therewith. The piezoelectric and protector plates are dimensioned such that a wave of resonant frequency traveling between the excitation face and the loaded/sensing face, forms a substantially continuous-phase wave, at substantially peak amplitude, at the energy interface. By doing so the device decouples the electrical thickness of the wave device from the mechanical thickness thereof.

Abstract: Deterioration of the Q value caused by the thermoelastic effect is suppressed. Since a first depth of a first groove and a second depth of a second groove are smaller than a distance between a surface including a third surface and a surface including a fourth surface, the first and second grooves do not penetrate between the surface including the third surface and the surface including the fourth surface. In addition, the sum of the first depth of the first groove and the second depth of the second groove is greater than the distance between the third and fourth surfaces, a heat transfer path between a first expandable portion (the first surface) and a second expandable portion (the second surface) cannot be formed as a straight line. As such, the heat transfer path between the first expandable portion (the first surface) and a second expandable portion (the second surface) is made to detour to the first and second grooves and and thus be lengthened.

Abstract: An inertial drive actuator includes a fixed member, a displacement generating mechanism which is connected to the fixed member, and which generates a minute displacement in a first direction and a second direction, a vibration substrate which reciprocates by the minute displacement generated by the displacement generating mechanism, a mobile object which is disposed on the vibration substrate, and which is movable by inertia, a driving mechanism which is connected to the mobile object, and which controls a frictional force between the mobile object and the vibration substrate by making an electromagnetic force to act in the mobile object by applying a current, a detecting electrode having a position detection function, which is disposed on a flat surface of the vibration substrate, to be facing the mobile object via an insulating body layer, and which is formed such that, an area face-to-face thereof with the mobile object either increases continuously or decreases continuously with the movement of the mobile

Abstract: The present invention relates to a micro-electro-mechanical systems (MEMS) vibrating structure supported by a MEMS anchor system, and includes a single-crystal piezoelectric thin-film layer having domain inversions, which determine certain vibrational characteristics of the MEMS vibrating structure. The MEMS vibrating structure may have dominant lateral vibrations or dominant thickness vibrations. The single-crystal piezoelectric thin-film layer may include Lithium Tantalate or Lithium Niobate, and may provide MEMS vibrating structures with precise sizes and shapes, which may provide high accuracy and enable fabrication of multiple resonators having different resonant frequencies on a single substrate.

Abstract: A method for converting mechanical energy into electrical energy by at least one piezoelectric element and at least one variable capacitor. The method: a) mechanically deforms the piezoelectric element; b) recovers charges produced by the deformation of the piezoelectric element; c) transfers the charges from the piezoelectric element to the capacitor; d) modifies the capacitance of the capacitor; and e) recovers at least some of the electrical energy. A device for converting mechanical energy into electrical energy includes a piezoelectric element and a variable capacitor. The piezoelectric element is capable of transferring charges to the capacitor.

Abstract: A thin film piezoelectric resonator suppresses deterioration of impedance at antiresonant frequency and has a high Q value. The thin film piezoelectric resonator is provided with a semiconductor substrate (8); an insulating layer (6) formed on the semiconductor substrate (8) in contact with the surface of the semiconductor substrate; and a piezoelectric resonator stack (14) formed above the insulating layer and having a lower electrode (10), a piezoelectric layer (2) and an upper electrode (12) in this order from the insulating layer side. An oscillation space (4) is formed corresponding to an oscillation region where the lower electrode (10) and the upper electrode (12) of the piezoelectric resonator stack (14) overlap each other in the thickness direction. The fixed charge density in the insulating layer (6) is 1×1011 cm?2 or less. At the time of manufacturing the thin film piezoelectric resonator, the insulating layer is formed in contact with the semiconductor substrate and then, heat treatment at 300° C.

Abstract: A MEMS structure having a temperature-compensated resonator member is described. The MEMS structure comprises an asymmetric stress inverter member coupled with a substrate. A resonator member is housed in the asymmetric stress inverter member and is suspended above the substrate. The asymmetric stress inverter member is used to alter the thermal coefficient of frequency of the resonator member by inducing a stress on the resonator member in response to a change in temperature.

Abstract: There are provided a piezoelectric vibrating reed which can be reliably bonded ultrasonically and which can be efficiently manufactured, a piezoelectric vibrator, a method of manufacturing a piezoelectric vibrator, an oscillator, an electronic apparatus, and a radio-controlled timepiece. A piezoelectric vibrating reed includes: a piezoelectric plate having vibrating portions and a base portion adjacent to the vibrating portions; excitation electrodes formed in the vibrating portions; mount electrodes formed in the base portion; lead-out electrodes for making the excitation electrodes and the mount electrodes electrically connected to each other; and a passivation film which is formed of an electrically insulating material and covers the excitation electrodes and the lead-out electrodes. These electrodes disposed on one surface of the base portion are formed only in a region covered by the passivation film.

Abstract: There are provided a method of manufacturing a piezoelectric vibrating reed capable of improving the reliability of a product by sorting out a defective product correctly, a piezoelectric vibrating reed, a piezoelectric vibrator having a piezoelectric vibrating reed, an oscillator, an electronic apparatus, and a radio-controlled timepiece. In a resist pattern forming step, a resist pattern is formed by performing contact exposure on a photoresist film in a state where a photomask is in close contact with the photoresist film. Before the resist pattern forming step, a photomask treatment step is included in which when a defect is found in an outer shape equivalent region equivalent to the outer pattern in the photomask, a part of a light shielding film pattern is removed to change the shape of the outer shape equivalent region where damage is present.

Abstract: There is provided a piezoelectric thin-film resonator including a substrate, a lower electrode disposed on the substrate, a piezoelectric film disposed on the lower electrode, an upper electrode disposed on the piezoelectric film in such a manner that a portion of the upper electrode is opposed to the lower electrode, and a mass element disposed on the upper electrode in a portion of an edge of the region of the upper electrode in which the upper electrode and the lower electrode are opposed to each other.

Abstract: A drive circuit for a high-frequency agitation source includes a signal generator generating a train of low voltage square-wave pulses at a drive frequency, a booster including a boost inductor generating a back EMF and configured to produce a high-voltage pulse train in response to the low-voltage square-wave pulse train and a filter producing a drive signal having a pre-determined harmonic of the drive frequency, the drive signal being used to drive the high-frequency agitation source. The drive circuit is particularly suitable for use with piezoelectric crystals.

Abstract: A quartz crystal unit comprises a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase and having at least one groove having at least one stepped portion formed in at least one of opposite main surfaces of each of first and second quartz crystal tuning fork tines. An electrode is disposed on the at least one stepped portion of the at least one groove so that the electrode of the first quartz crystal tuning fork tine has an electrical polarity opposite to an electrical polarity of the electrode of the second quartz crystal tuning fork tine. The quartz crystal unit comprising the quartz crystal tuning fork resonator has a capacitance ratio r1 of a fundamental mode of vibration less than a capacitance ratio r2 of a second overtone mode of vibration.