Abstract: A mechanical resonator device which has a phenomena-dependent electrical stiffness is provided. The phenomena may be temperature or acceleration, for example. The device includes a substrate and a resonator supported above the substrate by supports. The device further includes an electrode supported above the substrate adjacent the resonator by supports to obtain an electrode-to-resonator gap wherein electrical stiffness generated across the gap is phenomena-dependent to take instability of resonant frequency of the device caused by the phenomena into consideration.

Abstract: The active/passive absorber for extended vibration and sound radiation control includes principally two layers. The first layer has a low stiffness per unit area which allows motion in the direction perpendicular to its main plane. The second layer is principally a mass layer. These two combined layers have a frequency of resonance close to one of the main structure. The dynamic behavior of the coupled system makes the active/passive absorber a passive absorber; however, the first layer can be electrically actuated to induce motion in the direction perpendicular to its main plane. This addition property induces and/or changes the motion of the mass layer and therefore improves the dynamic properties of the active/passive absorber system. The acive/passive absorber can have multiple mass layers and multiple elastic layers stacked one on top of the other. In addition, the mass layers can be continuous or discretized, and have varying thicknesses and shapes for sections and/or segments in the mass layer.

Abstract: A fetal heart monitoring system preferably comprising a backing plate having a generally concave front surface and a generally convex back surface, and at least one sensor element attached to the concave front surface for acquiring acoustic fetal heart signals produced by a fetus within a body. The sensor element has a shape that conforms to the generally concave back surface of the backing plate. In one embodiment, the at least one sensor element comprises an inner sensor, and a plurality of outer sensors surrounding the inner sensor. The fetal heart monitoring system can further comprise a web belt, and a web belt guide movably attached to the web belt. The web belt guide being is to the convex back surface of the backing plate.

Abstract: A unidirectional acoustic probe including a high-performance interconnection network, and a method of manufacturing such a probe. The unidirectional acoustic probe includes linear piezoelectric transducers on the surface of a dielectric film. The dielectric film includes a connection device to electrically connect the piezoelectric transducers to a control device. The connection device includes primary connection pads, facing the piezoelectric transducers, secondary connection pads, offset with respect to the piezoelectric transducers, so that the transducers can be connected to the control device, and conducting tracks connecting the primary connection pads to the secondary connection pads. The conducting tracks are in a direction perpendicular to the direction defined by a major axis of the piezoelectric transducers.

Abstract: A method of manufacturing an inkjet head includes forming a plurality of electrodes at predetermined positions on an upside of a base piezoelectric layer. A plurality of piezoelectric layers are laminated on the upside of the base piezoelectric layer and an electrode is formed on an upside of each of the laminated piezoelectric layers. The method further includes sintering the base piezoelectric layer and the laminated piezoelectric layers, and polarizing the base piezoelectric layer and the laminated piezoelectric layers, respectively. A part of the laminated piezoelectric layers located at a position corresponding to each of peripheral portions is removed so that the piezoelectric device can be completed.

Abstract: A method of fabricating a piezoelectric/electrostrictive device including a driving portion, a movable portion, and a fixing portion for holding the driving portion and the movable portion. The driving portion includes a pair of thin plate portions facing each other, and a film-like piezoelectric/electrostrictive element formed on at least a part of the outer surface of at least one of the thin plate portions. A ceramic green laminate including at least one ceramic green sheet constituting one of the thin plates and at least one ceramic green sheet having at least one hole formed thereon is formed. The ceramic green laminate is sintered to produce a ceramic laminate. A piezoelectric/electrostrictive element is formed by a film formation method on the outer surface of the thin plate portion of the ceramic laminate. The ceramic laminate is then cut with the piezoelectric/electrostrictive element formed thereon.

Abstract: A piezoelectric/electrostrictive (P/E) device includes at least one actuator section secured to thin plate sections with an adhesive. The actuator section includes a multilayered member including at least three actuator films, each of which include a P/E layer and electrode films. One or more holes or recesses are formed in portions of the thin plate sections on which the P/E elements are formed. The electrode films contact upper and lower surfaces of respective P/E layers and alternately extend to opposite surfaces thereof. End surface electrodes electrically connect an electrode film that contacts one of the P/E layers and an electrode film that contacts another one of the P/E layers. The end surface electrodes are electrically connected to terminals which are provided on a surface of an outermost layer of the P/E layers, and which are separated from one another by a predetermined distance.

Abstract: FBAR device includes a membrane supporting layer between a substrate and a membrane layer, surrounding an air gap region. The membrane supporting layer support the membrane layer to obtain a robust structure. The substrate has a first area and a second area surrounding the first area. The membrane supporting layer is formed on the second area of the substrate so as to form the air gap on the first area of the substrate. The membrane layer is formed on the membrane supporting layer and the air gap. A first electrode is formed on a portion of the membrane layer. A piezoelectric layer is formed on a portion of the first electrode. A second electrode is formed on a portion of the piezoelectric layer.

Abstract: A piezoelectric resonator is disclosed. In one embodiment the piezoelectric resonator includes a resonating member having a bi-directionally adjustable resonance frequency, the resonating member including a semiconductor material of a semiconductor-on-insulator wafer, the semiconductor-on-insulator wafer including an oxide layer adjacent to the semiconductor material and a handle layer adjacent to the oxide layer, the oxide layer disposed between the handle layer and the semiconductor material, and electrode, and a piezoelectric material disposed between the semiconductor material and the electrode, and a capacitor created by the semiconductor material and the handle layer separated by an air gap formed out of the oxide layer, wherein the capacitor is configured to receive a direct current voltage that adjusts the resonance frequency of the resonating member.

Abstract: A vibrating gyroscope includes a vibrator which is retained by supporting members at one end of the supporting members and a housing to which the supporting members are fixed at the other end of the supporting members. A rigid reinforcing plate made of a metal is embedded in the housing made of a resin by insert molding. The rigid reinforcing plate is continuous between positions near fixing portions at which the supporting members are fixed to the housing. Therefore, the rigidity of the housing is increased and the vibration of the vibrator is prevented from being transmitted to the outside. In addition, the temperature drift performance is prevented from being degraded.

Abstract: In a system for overcoming or at least damping oscillations in or through channels (9) which carry fluid in a component, in particular coolant in cooling channels in an optical element (1), in particular a projection objective lens (1a) for semiconductor lithography, oscillations which occur are detected and evaluated by sensors (5), after which the result is passed, in the form of an adaptronic control loop to piezoelectric elements (9), which are integrated in the optical element, and are in the form of thin plates, films or layers which, when activated, produce the oscillations or frequencies which counteract oscillations and natural frequencies produced by the turbulence.

Abstract: A resonator device includes a piezoelectric resonator having a detuning layer sequence arranged on the piezoelectric resonator. The detuning layer sequence includes at least a first layer having a high acoustic impedance and a second layer having a low acoustic impedance.

Abstract: A piezoelectric transducer module includes first and second transducer units, each of which includes a conductive substrate portion that extends in a first direction and that has first and second surfaces opposite to each other in a second direction transverse to the first direction. At least one of the first and second surfaces has a piezoelectrically active coating coated thereon. The first and second transducer units are spaced apart from each other in the second direction. A connecting unit extends in the second direction and has opposite ends connected to the substrate portions of the first and second transducer units, respectively. The substrate portions of the first and second transducer units and the connecting unit are formed from a unitary conductive plate that is folded at junctions of the connecting unit and the substrate portions of the first and second transducer units.

Abstract: A first cermet layer, constituting a first wiring pattern, and a second cermet layer, constituting an insulating layer filling gaps in the first wiring pattern, are formed on a ceramic substrate. Thereafter, the first and second cermet layers are fired to simultaneously produce the first wiring pattern and the insulating layer. Next, a PZT paste constituting a piezoelectric/electrostrictive layer is formed and thereafter fired to produce the piezoelectric/electrostrictive layer. Thereafter, a third cermet layer, constituting a second wiring pattern, is formed and fired to produce the second wiring pattern, thereby fabricating a wiring board.

Abstract: A method for fabricating a Thin Film Bulk Acoustic Wave Resonator (FBAR). The method comprises the steps of: (A) forming a sacrificial layer comprising one of a metal and a polymer over a selected portion of a substrate; (B) forming a protective layer on the sacrificial layer and on selected portions of the substrate; (C) forming a bottom electrode layer on a selected portion of the protective layer; (D) forming a piezoelectric layer on a selected portion of the bottom electrode layer and on a selected portion of the protective layer; (E) forming a top electrode on a selected portion of the piezoelectric layer; and (F) removing the sacrificial layer to form an air gap. The use of a metal or a polymer material to form sacrificial layers has several advantages over the use of zinc-oxide (ZnO) to form such layers. In accordance with a further aspect of the invention, an FBAR is provided which includes a glass substrate.

Abstract: A filter assembly includes a ceramic substrate. A die including a film bulk acoustic resonator receive-band filter, positioned on the ceramic substrate, having an input and an output, includes a plurality of film bulk acoustic resonators. The filter assembly includes a first and a second loop of current. The first loop includes a first wire bond connected to the input of the die, and a second wire bond connected to a first one of the plurality of film bulk acoustic resonators. The second loop includes a third wire bond connected to the output of the die, and a fourth wire bond connected to a second one of the plurality of film bulk acoustic resonators, wherein the first loop induces parasitic current in the second loop. The first and the second wire bonds are positioned proximate to one another to minimize the area of the first loop, and the third and the fourth wire bonds are positioned proximate to one another to minimize the area of the second loop.

Abstract: A piezoelectric/electrostrictive device that includes a base having a pair of right and left movable parts and a fixing part disposed at one end thereof, and piezoelectric/electrostrictive elements disposed on the sides of the movable parts of the base. Accordingly, the piezoelectric/electrostrictive device is fabricated to have a construction with fewer components. The piezoelectric/electrostrictive device having a construction with fewer components is provided by adopting a base having an integral structure formed by bending an original plate stamped into a shape that delineates a plane development of the base.

Abstract: A quartz crystal unit has a quartz crystal tuning fork resonator capable of vibrating in a flexural mode, a case for housing the quartz crystal tuning fork resonator, and a lid for covering an open end of the case. The quartz crystal tuning fork resonator has a tuning fork base, a pair of tuning fork tines connected to the tuning fork base, a series of grooves each formed on opposite main surfaces of each of the tuning fork tines, and a series of electrodes each disposed in a respective one of the grooves. When W and W2 represent a width of each tuning fork tine and a width of at least one of the grooves formed in the tuning fork tines, respectively, W2 is within a range of 0.03 mm to 0.12 mm, and a ratio (W2/W) is greater than 0.35 and less than 1.

Abstract: A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. The resonator is fabricated on a substrate by fabricating a bottom electrode layer and a piezoelectric (PZ) layer over the bottom electrode layer. A selected portion of the PZ layer is partially etched. Then, a top electrode is fabricated over the selected portion of the PZ layer.

Abstract: A sparse array that uses a small fraction of a fully populated array but yields a radiation pattern that is suitable for high quality medical imaging. The sparse array consists of two or more separate zones for transmitting and receiving as opposed to the overlapping arrays of the prior art. More specifically, a preferred embodiment sets forth an inner array of transmit elements with a narrow effective aperture and a separate non-overlapping outer array of receive elements with a wide effective aperture. The combination of asymmetric apertures is particularly useful for parallel processing applications. This abstract is provided as a tool for those searching for patents, and not as a limitation on the scope of the claims.

Abstract: A thin film resonator having enhanced performance and a manufacturing method thereof are disclosed. The thin film resonator includes a supporting means, a first electrode, a dielectric layer and a second electrode. The supporting means has several posts and a supporting layer formed on the posts. The first electrode, the dielectric layer and the second electrode are successively formed on the supporting layer. The thin film resonator is exceptionally small and can be highly integrated, and the thickness of the dielectric layer of the resonator can be adjusted to achieve the integration of multiple bands including radio, intermediate and low frequencies. Also, the thin film resonator can minimize interference and has ideal dimensions because of its compact substrate, making the thin film resonator exceptionally small, yet comprising a three-dimensional, floating construction.

Abstract: Disclosed is a piezoelectric resonator that has a piezoelectric plate that has formed thereon a pair of main electrodes and has formed thereon a second electrode surrounding the peripheral edge of the main electrode with a gap being provided between the second electrode and a peripheral edge of the main electrode. The material of the main electrode and the material of the second electrode are differentiated from each other. As the material of the second electrode there is used a material the density of that is lower than the material of the main electrode. With this construction, there is obtained means for suppressing the occurrence of spurious due to an inharmonic mode generating in the high frequency piezoelectric resonator.

Abstract: A substrate, which is to be a vibration plate actuated by a piezoelectric element is prepared. A plurality of chip regions are defined on the substrate. A first common electrode of the piezoelectric element is formed on the substrate, so as not to extend beyond an outline of each of the chip regions. A first piezoelectric layer of the piezoelectric element is formed on the first common electrode. A drive electrode of the piezoelectric element is formed on the first piezoelectric layer, so as not to extend beyond the outline of each of the chip regions. A second piezoelectric layer of the piezoelectric element is formed on the drive electrode. A second common electrode of the piezoelectric element is formed on the second piezoelectric layer, so as not to extend beyond the outline of each of the chip regions. The substrate is cut so as to divide the chip regions from one another.

Abstract: A chip electronic component capable of being mounted with high density while preventing separation of bonded portions caused by solder fillets without requiring a case member having a complicated structure is provided at a low cost. The chip electronic component includes an electronic component element board including a circuit that defines an electronic component therein and having a pair of side surfaces and a lower surface, and a plurality of external electrodes extending over at least one of the side surface and the lower surface of the electronic component element and being electrically connected to the circuit provided therein. The electrode portion provided on the lower surface of the monolithic body as an electronic component element of each external electrode is provided with narrow portions and wide portions provided thereon, and the narrow portion continues to the external electrode portion provided on the side surface thereof.

Abstract: A vibrator for a vibratory gyroscope including a base part and at least one bending-vibration piece extending from the base part in a direction crossing the longitudinal direction of the base part and a fixing part for fixing one end of the base part. The base part and bending-vibration piece are formed to extend substantially in a specified plane. At the opposite side to one end of the base part, a projection projecting from the bending-vibration piece is provided, or at least a pair of resonant arms resonating with vibration of the base part, wherein the resonant arms project from the fixing part. With this arrangement, it is possible to detect a turning angular rate with high accuracy.

Abstract: A film bulk acoustic resonator is formed on a substrate. The film bulk acoustic resonator includes a layer of piezoelectric material having a first surface proximate the substrate, and a second surface distal from the substrate. The first conductive layer deposited on the first surface of the piezoelectric material includes a first portion having a surface on a different plane than a surface associated with a second portion.

Abstract: The present invention provides a piezoelectric thin film element with superior piezoelectric properties in which the condition of the crystal of the piezoelectric thin film is appropriately controlled, and a manufacturing method thereof, as well as a inkjet recording head, inkjet printer, or other liquid ejecting apparatus employing the same. The piezoelectric thin film element 40 comprises a top electrode 44, a bottom electrode 42, and a piezoelectric thin film 43 formed between the top electrode 44 and the bottom electrode 42, wherein the piezoelectric thin film 43 is structured so as to comprise a first layer 431 located nearest to the bottom electrode and second layers (433-436) that are located nearer to the top electrode than the first layer and that each have a thickness greater than that of the first layer 431.

Abstract: A dual mode filter includes a casing substrate on which an input electrode, an output electrode, two ground electrodes, and a relay electrode are provided, first and second filter elements mounted in parallel with each other on the casing substrate, and a cap fixed onto the casing substrate. The first and second filter elements each include a first terminal electrode, a second terminal electrode, a pair of segmented electrodes, a counter electrode, and a third terminal electrode. The first terminal electrode of the first filter element is connected to the input electrode, and the third terminal electrode is connected to one ground electrode. The first terminal electrode of the second filter element is connected to the output electrode, and the third terminal electrode is connected to the other ground electrode. The second terminal electrodes of the first and second filter elements are connected to the relay electrode.

Abstract: An energy harvesting device is provided. The energy harvesting device includes structural members covered with piezoelectric material resonating at different primary frequencies. As the structure to which the energy harvesting device is secured vibrates over a range of frequencies, more than one member resonates or is close to resonance. As such, multiple members work simultaneously to create electrical energy.

Abstract: A piezoelectric/electrostrictive device including a substrate and a connection plate having a first end joined to the substrate and an opposed second end extending along a first direction, and first and second opposed sides along a second direction perpendicular to the first direction. A fixing plate is joined to the second end of the connection plate. A first side of a first diaphragm is joined to the first side of the connection plate and an opposed second side of the first diaphragm is joined to the substrate. A first side of a second diaphragm is joined to the substrate and an opposed second side of the second diaphragm is joined to the second side of the connection plate. A piezoelectric/electrostrictive element is provided on at least a portion of at least one planar surface of at least one of the diaphragms.

Abstract: A fabricating method of a piezoelectric/electrostrictive device including a driving portion having thin plates facing each other and a film-like piezoelectric/electrostrictive element formed on the surface of at least one thin plate of the thin plates, and a fixing portion and a movable portion in rectangular solid form. The thin plates are spanned so that the side faces of the movable portion and the fixing portion are continuous. The fabricating method includes steps of preparing a laminated body of green sheets comprising at least one green sheet to constitute the thin plate, and at least one green sheet with at least one hole formed thereon, sintering a green-sheet laminated body, and forming a piezoelectric/electrostrictive element on an outer surface of the thin plates of the sintered body obtained.

Abstract: A method for fabricating an acoustic resonator, for example a Thin Film Bulk Acoustic Resonators (FBAR), on a substrate. A depression is etched and filled with sacrificial material. The FBAR is fabricated on the substrate spanning the depression, the FBAR having an etch hole. The depression may include etch channels in which case the FBAR may include etch holes aligned with the etch channels. A resonator resulting from the application of the technique is suspended in air and includes at least one etch hole and may include etch channels.

Abstract: The present invention provides a composite vibrator that can maintain high sensitivity even when miniaturized. The composite vibrator includes tuning bar vibrators having the same length and support members for supporting the tuning bar vibrators. The tuning bar vibrators are arranged in a direction orthogonal to the longitudinal direction to be coupled with each other near nodes of bending vibrations occurring at both free ends of the tuning bar vibrators. In this arrangement, since the tuning bar vibrators are coupled with each other, the mass of the composite vibrator increases. Thus, even when the length of the longitudinal direction of the tuning bar vibrator is reduced, due to the increased mass, higher sensitivity for the detection of an angular velocity can be obtained.

Abstract: A closed loop motion control system employing at least one relaxor actuator which controls the position of a moving member having mass by controlling an electric field applied to the relaxor actuator. The actuator comprises a body of relaxor material dimensionally variable under the influence of the electric field applied in the form of a voltage to electrodes on at least two surfaces of the actuator. The voltage is applied in response to a feedback signal produced by at least one feedback sensor, which may be a displacement sensor or some other type of sensor. Thus, by constantly monitoring the displacement or other variable of the actuator device, the position of the moving member may be precisely controlled.

Abstract: The active/passive absorber for extended vibration and sound radiation control includes principally two layers. The first layer has a low stiffness per unit area which allows motion in the direction perpendicular to its main plane. The second layer is principally a mass layer. These two combined layers have a frequency of resonance close to one of the main structure. The dynamic behavior of the coupled system makes the active/passive absorber a passive absorbe; however, the first layer can be electrically actuated to induce motion in the direction perpendicular to its main plane. This addition property induces and/or changes the motion of the mass layer and therefore improves the dynamic properties of the active/passive absorber system.

Abstract: Control of fluid motion within microcavities is carried out using microstructures in the cavities having cantilever elements that are coupled to a substrate to receive vibrations therefrom. The cantilever elements can be excited into resonance at one or more resonant frequencies. By selection of the shape of the cantilever elements, their position in the microcavity, the spacing of the cantilever elements from the walls of the cavity, and the frequency at which the cantilever elements are excited, the direction of pumping of fluid through the cavity can be controlled, blocked or diverted.

Abstract: An electrical transformer including a tank containing transformer fluid, a transformer core and winding subassembly disposed in the transformer fluid within and spaced apart from the tank. An active device, disposed in the transformer fluid within the tank, various the volume of the transformer fluid in order to reduce pressure waves generated by the vibration of the core and winding subassembly during electromagnetic operation. The active device includes at least a cell having a main body and a corrugated membrane connected to the main body in order to realize a sealed container able to maintain a low pressure atmosphere inside, and an actuator placed inside the sealed container and solidly connected to the corrugated membrane.

Abstract: A process and apparatus for treating a wellbore, comprising subjecting a substantially same portion of the wellbore to vibratory waves produced by a plurality of vibratory wave generators. The vibratory waves may have about the same frequency or a plurality of frequencies, and the frequencies may partially overlap, not overlap, or be modulated across a range. Additionally, the frequencies may be modulated in an oval, hoop, and flexural modes. The vibratory waves may be produced by firing the vibratory wave generators simultaneously or in sequence. Combinations of a vibrating pipe, piston pulser, or valve may be used as vibratory wave generators. In a preferred embodiment, the thickness and change of thickness of a mudcake on the interior surface of a wellbore are measured to evaluate the effectiveness of the wellbore treatment.

Abstract: A method of controlling an object levitating apparatus is disclosed. The levitating apparatus levitates an object on a plurality of vibrating bodies with air pressure generated from sound waves produced by the vibrating bodies. Each vibrating body is vibrated by a corresponding vibrating apparatus. Each vibrating apparatus has an oscillator and a transducer. The transducer is actuated by the oscillator to vibrate the corresponding vibrating body. The method includes determining impedance of each transducer, and controlling each oscillator in accordance with the determined impedance to restrict displacement of the levitated object.

Abstract: A method is provided for fabricating a piezoelectric vibrator without degrading vibration characteristics. The piezoelectric vibrator has a vibration plate formed with a piezoelectric vibration portion and a frame portion integrally connected with a base portion of the piezoelectric vibration portion and surrounding the piezoelectric vibration portion. Opposite surfaces of the piezoelectric vibration plate are provided with a pair of lid members bonded to hermetically seal the piezoelectric vibration portion without interfering with vibration thereof. To achieve the bonding, a metal film is coated over substantially the entire area of opposite surfaces of the piezoelectric vibration plate. The metal film is patterned to form oscillation electrode films on opposite surfaces of the piezoelectric vibration portion and to form bonding films on opposite surfaces of the frame portion for bonding the frame portion to the pair of lid members.

Abstract: Disclosed is a high-sensitivity flexible ceramic sensor for detecting mechanical shocks and vibrations, which comprises a metal foil of a specified thickness as a substrate, a single-crystalline thin film of a piezoelectric ceramic material such as aluminum nitride and zinc oxide having a specified thickness formed on the substrate, a metallic electrode formed on the thin ceramic film and an external circuit connecting the metal foil and the electrode with insertion of an electric meter for measuring the piezoelectric voltage changes induced in the ceramic thin film.

Abstract: A method for producing an energy trap piezoelectric resonator which operates in a thickness longitudinal vibration mode and which includes a piezoelectric member and first and second vibrating electrodes disposed on respective major surfaces of the piezoelectric member, involves the use of a piezoelectric material having an R value and an A value which are selected such that Qe=C/(R×A), where R and A are the average pore size in micrometers and the porosity in percent of the piezoelectric member, respectively. Here, Qe is a value at a frequency to be used and C is a constant that is determined by the piezoelectric material of the piezoelectric member. An energy trap, thickness longitudinal piezoelectric resonator produced by this method has a sufficiently high response to a vibration mode to be used, without any limitation on the type of piezoelectric material and size of the piezoelectric member and the frequency to be used.

Abstract: A piezoelectric/electrostrictive device including a pair of mutually opposing thin plate sections and a fixation section for supporting the thin plate sections. A piezoelectric/electrostrictive element is arranged on each of the pair of thin plate sections. Movable sections, having mutually opposing end surfaces, are formed proximate the ends of the thin plate sections. A distance between the end surfaces is not less than a length of the movable sections.

Abstract: A piezoelectric shear resonator has a substantially rectangular-column piezoelectric element that excites a shearvibration mode and that has opposing substantially rectangular shear strain surfaces. The shear strain surfaces each have an aspect ratio at which the electromechanical coupling factor reaches substantially a maximum value. When the vertical dimension of the shear strain surfaces is D and the horizontal dimension thereof is Le, the aspect ratio Le/D is expressed by Le/D={&agr;·(S44E/S33E)1/2+&bgr;}±0.3, where S44E and S33E are elastic compliances, &agr;=0.27·n+0.45, &bgr;=1.09·n+0.31, and n is a positive integer.

Abstract: The present invention concerns the use of a sound generator circuit (22) including a piezoelectric vibrator (P3) as an acoustic wave receiver. The invention also concerns an electronic converter (20) including a sound generator circuit (22) provided with a piezoelectric vibrator (P3) as well as means supplying a reference voltage, characterized in that it further includes comparison means which compare the reference voltage to the voltage generated by the piezoelectric vibrator (P3) when the latter picks up an acoustic wave, said comparison means generating a pseudo-digital signal when the voltage generated by said vibrator (P3) exceeds said reference voltage. Finally the invention concerns a timepiece provided with a converter circuit (20) as described above, as well as a two-directional communication method via acoustic waves between an emitter unit and a receiver unit.

Abstract: A piezoelectric/electrostrictive device comprises a pair of mutually opposing thin plate sections, a movable section, and a fixation section for supporting the thin plate sections and the movable section. A piezoelectric/electrostrictive element is arranged on at least one thin plate section of the pair of thin plate sections. A hole is formed by the inner walls of the pair of thin plate sections, the movable section and the fixation section. A central portion of the movable section is cut off to form mutually opposing end surfaces in the movable section.

Abstract: A method of fabricating an air gap type Film Bulk Acoustic Resonator (FBAR) is provided. The FBAR fabrication method includes: (a) depositing and patterning a sub-electrode on a semiconductor substrate; (b) depositing and patterning a piezoelectric material layer on the sub-electrode; (c) depositing and patterning an upper electrode on the piezoelectric material layer; (d) forming a hole which passes through the upper electrode, the piezoelectric material layer and the sub-electrode; and (e) injecting a fluorine compound into the hole so that an air gap can be formed on the semiconductor substrate, and non-plasma etching the semiconductor substrate. Since the FBAR fabrication method does not include forming and eliminating the sacrificial layer in the fabrication process, the fabrication process is simplified. In addition, the air gap having the limitless frequency selectivity can be formed and the performance of the FBAR can be enhanced.

Abstract: In a piezoelectric resonator utilizing bending vibrations, three or more electrode layers and two or more piezoelectric layers are alternately laminated, at least two layers of the piezoelectric layers are polarized in the thickness direction, first and second end surface electrodes are provided in the end surfaces of the laminated piezoelectric layers, and the electrode layers are connected to each other by using the first and second end surface electrodes such that, in at least one piezoelectric layer, an electric field is generated in the same direction as the polarization direction of the piezoelectric layer, and such that, in at least one of the other piezoelectric layers, an electric field is generated in a direction that is opposite to the polarization direction of the piezoelectric layer.

Abstract: A passive piezoelectric damping system dissipates mechanical energy propagating through a structure by tuning a shunt inductance to a non-resonant mode of the structure. The damping system includes a piezoelectric element coupled to the structure, where the piezoelectric element converts the mechanical energy into electrical energy. The electrical energy has a reactive component. The damping system further includes a shunt circuit connected to the piezoelectric element for balancing the reactive component of the electrical energy with a shunt inductance. The shunt inductance is tuned to a non-resonant mode of the structure to reduce airborne noise transmission through the structure.

Abstract: The resonator according to the invention, which is intended to be mounted in a case, includes a tuning fork shaped part (42) with two parallel arms (44, 46) connected to each other by a base (48) and carrying electrodes (52, 54) to make them vibrate, these electrodes being connected to connection pads (60, 62) intended to be electrically connected to the exterior of the case. In accordance with the invention, the resonator (40) also includes a central arm (50) attached to the base (48) and located between the arms (44, 46) of the tuning fork shaped part (42), substantially equidistant from them, this central arm (50) having a greater mass than that of the arms of the tuning fork shaped part and the connection pads (60, 62) are carried by this central arm.