Abstract: An oscillator employs a single flat piezo-electric transducer as a frequency determining element. The transducer has first, second and third mutually orthagonal axes. The first and second axes lie in a selected one of first and second planes. The first plane is the plane of the transducer, the second plane is at right angles to the first plane. The third axis is perpendicular to the selected plane. The transducer has different modes of excitation in different planes which have different resonant frequencies. The oscillator has a positive feedback loop containing in series a high pass filter and a low pass filter which together [a] determine one selected mode of excitation of the transducer in the selected plane with an associated resonant frequency whereby the transducer resonates in the selected plane at the associated resonant frequency and [b] also prevent the transducer from being excited along the third axis.

Abstract: A device for transmitting electric energy to electric equipment, primarily computers and data nets, which device is intended to be connected between a voltage source and the electric equipment. The invention is characterized in that it is provided with a generator (30,31) comprising a piezo-electric element, which generator is intended to be connected to said voltage source and to generate a high-frequency mechanical wave motion, that a bar-shaped transmission member (32) is provided to transmit said motion to a receiver (33-35), which transmission member comprises a non-magnetic and electrically insulating material, in which the mechanical wave motion can be conducted, that said receiver, which is intended to be connected to the electric equipment, is capable to convert said mechanical wave motion into an electrically varying voltage by means of a piezo-electric element (33), which is in mechanical connection with said transmission member.

Abstract: A bio-sensor is mounted in a container and comprised of a receptor for selectively reacting with a specific biochemical substance in a sample liquid held in the container to bind thereon the specific biochemical substance and a resonator integrated with the receptor for detecting the amount of the specific biochemical substance bound to the receptor in terms of a resonant frequency shift of the resonator. A measuring circuit is connected to the sensor for measuring the resonant frequency shift of the resonator within the container; a switching valve operates during the reaction of the receptor with the specific biochemical substance to charge a sample liquid into the container to contact the sample liquid with the receptor to thereby effect the reaction and operates during the measurement of the resonant frequency shift to replace the sample liquid by a buffer liquid in the container to immerse the sensor in the buffer liquid to thereby prevent a fluctuation of the resonant frequency shift.

Abstract: There is disclosed Q-loss compensation apparatus for a piezoelectric sensor such as a quartz crystal microbalance or other resonant vibratory device wherein the vibration amplitude of the device is controlled by negative feedback in a manner to obviate the effect of energy loss associated with viscous damping of a large liquid drop on the quartz crystal face serving as an environment for an experiment to measure mass deposited on the crystal face. The specific apparatus includes an oscillator circuit for the vibratory device in which two generally similar variable gain amplifiers provide the regenerative feedback for maintaining oscillation. The negative feedback amplitude control circuit serves to maintain constant the output from the variable gain amplifier following the quartz crystal in the oscillator loop, and it thus maintains at a near constant value the product of the crystal vibration amplitude and the square root of the total gain in the oscillator loop.

Abstract: Electroacoustic resonating apparatus capable of generating resonances of tunable frequencies. The apparatus includes two transducers coupled to a ferrimagnetic substrate at opposite ends thereof. The first transducer converts an input signal into a signal that produces bulk acoustic waves in the ferrimagnetic substrate. The second transducer receives the bulk acoustic waves and converts them into electrical signals, or alternatively a single transducer which performs both input and output functions. Variable magnetizing means located proximate to the ferromagnetic substrate induces a magnetic field throughout the substrate wherein the magnetic field alters the frequencies of the resonance of the acoustic waves. By varying the magnitude of the magnetic field, the frequencies of the resonances may be varied, thereby allowing tuning of the apparatus.

Abstract: A piezoelectric fan includes a tuning-fork type vibrator having two sides. A first piezoelectric element is formed on each of the two sides of the vibrator. Further, an exciting electrode is formed on each of these first piezoelectric elements. Also, a feedback electrode is formed on one of the first piezoelectric elements an electrically insulated from the exciting electrode. Furthermore, a blade is attached to the tip of each of the two sides of the vibrator. Then, this piezoelectric fan is driven in a self-exciting fashion by feeding an output from the feedback electrode to the exciting electrode. Also, in this piezoelectric fan, a vibrational node is formed at nearly the middle point of the vibrator at free vibration.

Abstract: A transducer assembly includes a piezoelectric transducer and a support member encasing the transducer. The transducer and the support member may have commonly disposed openings. The support member has a progressively increasing thickness at progressive positions from the opening to distribute equally the stresses at the different positions on the piezoelectric transducer. A plurality of such transducer assemblies may be disposed at spaced positions in an oil well with the support members supported on a support rail extending through the well. The support rail serves as an electrical ground. A bus bar extends through the well at positions corresponding substantially to the centers of the transducer assemblies. The bus bar is supported by electrically insulating spacer members extending from the support rail. A ring is supported at one end by the support rail and is coupled at the other end to a tubing. The tubing envelopes, the transducer assemblies, the support rail, the bus bar and the spacer members.

Abstract: Microminiature resonant sensor structures are prepared according to micromachining/microfabrication techniques, which structures include thin-film deposits of piezoelectric materials. Such piezoelectric deposits may be excited electrically by including metallized conductive paths during fabrication, or optically. The resonant frequency of the sensor structure is varied by subjecting it to a physical variable, or measurand, such as pressure, temperature, flow rate, etc. Similarly, the resonant frequency of the devices may be detected electrically or optically. The microminiature resonant structures include ribbons and wires, hollow beam and cantilevered hollow beams, and single- and double-ended double beam resonant structures such as tuning forks.

Abstract: A piezoelelectric transducer usable preferably as a high-frequency ultrasonic probe for diagnostic inspection and the process for preparation thereof are disclosed.The piezoelectric transducer comprises a piezoelectric material layer, a pair of electrode layers formed respectively on the opposite surfaces of said piezoelectric material layer and for applying electric load across the piezoelectric material layer to thereby generate acoustic oscillation or for measuring electric energy generated due to the acoustic oscillation of the piezoelectric material layer, and an acoustic matching section containing at least one quarter-wave matching layer and formed on one of the electrode layers. The acoustic matching section includes an elelctric conductive layer therein.The acoustic matching section is formed by electro deposition, preferably by the electro painting method or electrophoretic method.The ultrasonic probe can be prepared of a frequency band higher than 7.

Abstract: A traveling wave droplet generator for a continuous stream ink jet printer comprising an ink filled tube connected in the vicinity of one end to an ink reservoir. A piezoelectric driver assembly is mounted at the fill end of the tube. The tube has openings connecting to orifices of an aperture plate bonded thereto. The tube has a terminator at the end opposite to the piezoelectric driver to suppress reflection and standing wave formation. The ink streams emitted through the nozzles of the aperture plate are stimulated by the traveling wave causing the streams to break up at predetermined distances from the nozzles.

Abstract: A vibrating beam resonator is formed with a unitary isolator mass at each end of the vibratory beam. Isolator springs connected to the unitary masses are joined to mounts. Forces applied to the mounts cause the vibrating beam frequency to vary to enable precise force measurements. With this arrangement, fewer cutting operations are required to produce the vibrating beam resonator than were necessary with known resonators. In a preferred embodiment, a side of the vibratory beam is formed by an edge of the crystal blank from which the resonator is cut to further reduce cutting time. This also permits cuts to be made from only one side of the blank.

Abstract: A force transducer device adapted to function in a system having electrical means to cause the device to oscillate at its natural resonant frequency and means to monitor said frequency, the device having an intermediate resilient member being capable of mechanically oscillating at a natural resonant frequency, at least two piezoelectric transducers mounted on said resilient member and means for connecting the transducer sheets into said system, is disclosed herein.

Abstract: A vibration wave motor includes circular shape vibration part having a helical stepped portion inside or outside thereof; a unit, coupled to said vibration part for causing the vibration part to generate a travelling vibration wave propagating along a circumferential direction of the vibration part; and a movable part having a stepped portion threadably engaged with the helical stepped portion, the movable part being frictionally driven by the travelling vibration wave generated by the vibration part.

Abstract: An oscillator utilizes a piezo-electric transducer as a frequency determining element. The transducer, when unloaded, has a resonant frequency which determines the oscillation frequency and exhibits a predetermined level of amplitude excursion. The transducer, when moved into engagement with a conduit through which fluid flows, becomes loaded and exhibits a change of resonant frequency, whereby the oscillator frequency changes, and also exhibits a change in level of amplitude excursion. The amount of oscillator frequency change and the change in excursion level have respective values when the fluid flowing in the conduit past the transducer is bubble free which differ from the respective values when the fluid contains bubbles. Circuitry responsive to at least one of the changing frequency and amplitude values produces a signal when a selected one of the bubble free and bubble containing conditions is detected.

Abstract: A knock sensor includes a circular mounting surface with a flat, self-resonant vibration element and piezoelectric disk coaxially mounted thereon. The vibration element comprises a central circular portion and a pair of outer semicircular portions of larger radius, the outer semicircular portions being shifted in opposite direction along their common border from the axis by an equal distances and each being divided into an equal number of sectors by radial slots centered on the axis and extending outward from the first radius with equal angles therebetween to from diametrically opposed pairs of similarly shaped and sized vibrating sectors. The pairs of sectors have resonant frequencies together forming a sensor passband wider than the individual passbands of the pairs taken separately. In addition, differences in resonant frequency between members of a pair due to misalignment of the axes of the vibration element and mounting surface do not significantly affect the sensor passband.

Abstract: Viscosity of small fluid samples is measured by coupling an ultrasonically energized shear transducer to a fluid sample through a polymeric coupling layer having a thickness and shear impedance such as to produce a zero total reflection coefficient at least at one particular viscosity. In general, the thickness will be slightly greater than one-quarter wavelength. The use of the coupling layer produces a large increase in sensitivity, eliminates the need for sophisticated and expensive electronic circuitry, and makes it possible to determine viscosity by very simple circuitry responsive to transducer current.

Abstract: A transducer for transmitting or receiving ultrasound in on-line applications is disclosed. The transducer comprises a piezoelectric element having the shape of a parallelepiped, and a nosepiece rigidly attached to a surface of the element and adapted for contact with sheet material through which ultrasound is propagated.

Abstract: A sensor for generating a signal in response of a variation at the tactile face. The sensor comprises superposed transmitting and receiving layers, which are provided with electrodes for the supply and pick-up of electrical signals to the transmitting layer and from the receiving layer respectively. With a high acoustic impedance of the boundary medium adjacent to the transmitting layer and a low acoustic impedance of the boundary medium adjacent to the receiving layer or vice versa, the sum of the thicknesses of the transmitting and receiving layers is an odd number of v/4f. With similar impedances, either low or high, of the said boundary media the aforesaid sum is an even number of v/4f. v is the propagation velocity of the acoustic vibration in the material of the transmitting and receiving layers and f the frequency of the signal supplied.

Abstract: The invention provides a string resonator vibrating under flexion whose oscillation is maintained by piezoelectric, electrostatic or magnetic exitation means.Decoupling is obtained by inertia masses which oscillate in the vibration plane of the string, between the string and fixing supports, with a movement of rotation about an axis orthogonal to the vibration plane of the string and at the level of flexible elements. The resonator is easy to manufacture, inexpensive and hase a good coefficient of quality. It may be used for force, pressure sensors or gyroscopes.

Abstract: Piezoelectric type liquid level sensor for detecting whether the level of various liquids such as oil of an internal combustion engine, a generator or the like is a predetermined value or higher or not, and method of making the sensor. The sensor is arranged to eliminate the influence of the weight of the lead wires on the vibration element and to facilitate its assembly. The sensor may be provided with a damper member for increasing the sensitivity.

Abstract: A piezoelectric device is used to determine the absolute weight of an unknown sample by comparison to a control sample whose weight is known. A piezoelectric driver is resiliently attached to a base that is isolated from vibrations. A piezoelectric receiver and a reed are resiliently attached to the piezoelectric driver so that (1) the reed is moved in response to motion of the piezoelectric driver, and (2) the piezoelectric receiver gives an electric signal out proportional to motion of the system. The entire system is set to operate on the leading edge of the resonant frequency for the system. By applying an oscillating sine wave voltage, such as 140 hertz, to the piezoelectric driver, and by applying a known mass to the tip of the reed, a first output is obtained from the piezoelectric receiver which represents the calibrated weight. Next by exchanging an unknown sample for the known mass, a second output is obtained that represents the second weight.

Abstract: A piezoelectric vibrator comprises a mechanical vibrating member having, an aluminum layer formed on a surface of the vibrating member, and a piezoelectric transducer overlaying the aluminum layer.

Abstract: This invention is an improved traveling wave ring resonator utilizing only one source of waves. The standard traveling wave ring resonator uses two wave sources phased 90 degrees apart and physically separated by a quarter wavelength to separately excite two equal-frequency standing wave modes which make up a traveling wave. The present invention uses perturbations of the ring resonator to shift the frequency of the standing wave modes, by specified amounts, and to correctly fix their position, to allow a single wave source to properly excite the standing wave modes which comprise a traveling wave. This invention has application to traveling wave ring resonators in acoustics, mechanical devices, and electromagnetic devices, as well as to simply-connected resonators to be excited in rotating wave modes. Specific applications include improved thermoacoustic traveling wave heat engines and pumps, simplified surface wave motors, and energy efficient wave pools for recreational purposes.

Abstract: A transducer assembly includes a piezoelectric transducer and a support member encasing the transducer. The transducer and the support member may have commonly disposed openings. The support member has a progressively increasing thickness at progressive positions from the opening to distribute equally the stresses at the different positions on the piezoelectric transducer. A plurality of such transducer assemblies may be disposed at spaced positions in an oil well with the support members supported on a support rail extending through the well. The support rail serves as an electrical ground. A bus bar extends through the well at positions corresponding substantially to the centers of the transducer assemblies. The bus bar is supported by electrically insulating spacer members extending from the support rail. A ring is supported at one end by the support rail and is coupled at the other end to a tubing. The tubing envelopes, the transducer assemblies, the support rail, the bus bar and the spacer members.

Abstract: A method of bonding elements together with a bond of high strength and good electrical conductivity which comprises: applying an unfilled polyimide resin between surfaces of the elements to be bonded, heat treating said unfilled polyimide resin in stages between a temperature range of about 40.degree. to 365.degree. C. to form a strong adhesive bond between said elements, applying a metal-filled polyimide resin overcoat between said elements so as to provide electrical connection therebetween, and heat treating said metal-filled polyimide resin with substantially the same temperature profile as the unfilled polyimide resin. The present invention is also concerned with an adhesive, resilient, substantially void free bonding combination for providing a high strength, electrically conductive adhesive attachment between electrically conductive elements which comprises a major amount of an unfilled polyimide resin and a minor amount of a metal-filled polyimide resin.

Abstract: The disclosure is directed to a piezoelectric vibrator or resonator which includes a vibrating plate employing expansion mode vibration, and a groove or grooves formed at a center and/or in the vicinity of the center of the vibrating plate in a direction intersecting sides of the vibrating plate contributing to the vibration so as to make vibration propagating speed slower than that in the absence of the groove or grooves, and also to a method of adjusting vibrating frequency of such a piezoelectric vibrator.

Abstract: An isolation system which prevents energy from being transferred by the vibrating member of a resonator to its end mounts is formed by having isolator springs coupled to respective isolation masses. Each of the isolation masses is connected to a corresponding end mount. Each pair of isolator springs is angled in such a way that the axes of the isolator springs would intersect at a node located somewhere along the longitudinal axes of the vibrating member. Consequently, the axes of the isolator springs are positioned perpendicularly to loci of motions representing the direction of force and moment reactions produced at the roots of the vibrating member.

Abstract: A force transducer having a vibratory member either a beam or a string and means for effectively isolating the vibratory member from its end mounts over the range of its operating frequencies to eliminate energy loss to the mounts. The axial stresses, either tension or compression, are directly transferred to the vibratory member to affect its natural resonant frequency. Isolation at vibration frequencies is effected by the cooperation of combined isolator masses and isolator springs with the vibratory member. The isolator masses comprise two bars extending from each end support of the vibratory member, each being coextensive with a portion of the support member. The pairs of masses are axially separated. The isolator springs comprise two single thin, spaced resilient members, each isolator spring connecting a single end support of the member and a single transducer end mount.

Abstract: A digital differential pressure sensor with relatively low sensitivity to common mode line pressure errors. The sensor includes an airtight enclosure having a pair of pressure ports through which pressures are coupled to opposite sides of a pressure-sensing diaphragm, bellows, or Bourdon tube. The pressure-sensing elements generate torques which are transmitted by a shaft to stress-sensitive resonators which are isolated from the torque-producing elements by a sealed, flexible tube.

Abstract: A piezoelectric vibrator comprises a substrate consisting of Elinvar, in which a vibrating element is formed as an island. The vibrating element is connected to and supported by strip-like connecting portions which are connected with the surrounding frame. A piezoelectric film is formed on the surface of the vibrating element. Of the longitudinal end portions of the vibrating element in the vicinity of the connecting portions, one main surface side is formed as a thin-plate portion by etching, while the rest of the vibrating element has its thickness intact. The longitudinal edges of vibrating element are defined by etching carried out simultaneously with or after the previous etching step.

Abstract: A vibrating element for the vibration under an expansion mode has a substrate made of a constant modulus alloy having a plate shape which is symmetrical along a line extending across the substrate. At least one pair of projections extends from opposite sides of the substrate symmetrically with respect to the line. A thin piezoelectric film is deposited on the substrate, and a vibration electrode film is further deposited on the piezoelectric film. The pair of projections are provided to be trimmed to adjust the vibration frequency of the vibrating element.

Abstract: A liquid level indicator system is provided for sensing the presence of liquid at a preselected level in a liquid containing container. A piezoelectric reed transducer is disposed in the container for detecting vibrational movement and for producing an electrical signal in response to the vibrational movement. Operationally coupled to the transducer is a paddle which is sized to be immersed in the liquid when the liquid is present at the proper level. Immersion of the paddle in the liquid inhibits the transducer from vibrating due to fluid resistance against the paddle and accordingly inhibits an electrical signal output from the transducer. A control circuit is provided for sensing the electrical signal generation and for generating an alarm signal representative of low liquid level. A tubular housing is provided for containing a level of liquid representative of liquid level in the liquid container. The reed is preferably tuned to a preselected natural frequency sympathetic to ambient system vibrations.

Abstract: The present invention provides a piezoelectric thin-film resonator comprising a non-piezoelectric film layer formed on a substrate, a lower electrode, a piezoelectric film layer and an upper electrode. An air-gap layer is formed between the non-piezoelectric film and the substrate to facilitate vibration of the piezoelectric film layer at the resonate frequency. The resulting resonating device is mechanically strong while at the same time being capable of operating at high frequency.

Abstract: A broadband longitudinal vibrator transducer having a laminar head mass section including at least three layers coupled to electromechanical transducer elements. The head section includes a forward head mass, a compliant member abutting the forward head mass and a rear head mass abutting both the compliant member and the transducer elements. The compliant member allows the head mass section to mechanically resonate in at least two frequencies expanding the bandwidth of the transducer. The compliant member can be an active transducer element.

Abstract: A piezoelectric device is used to determine a ratio of a second weight with an original weight where the second weight is less than the original weight. A piezoelectric driver is resiliently attached to a base that is isolated from vibrations. A piezoelectric receiver and a reed are resiliently attached to the piezoelectric driver so that (1) the read is moved in response to motion of the piezoelectric driver, and (2) the piezoelectric receiver gives an electric signal out proportional to motion of the system. The entire system is set to operate on the leading edge of the resonant frequency for the system. By applying an oscillating sine wave voltage, such as 140 hertz, to the piezoelectric driver, and by applying an unknown mass to the tip of the reed, a first output is obtained from the piezoelectric receiver which represents the original weight. Next by removing part of the mass by any convenient means, such as heat, a second output is obtained that represents the second weight.

Abstract: A piezoelectric vibrator capable of vibrating in an expansion mode of vibration comprising a piezoelectric vibrating element, composed of a vibrateable substrate, made of a constant elastic metal, a thin film of piezoelectric material and an exciting electrode layer. The substrate has a generally trapezoidal cross-sectional representation, as viewed in a direction perpendicular to the direction of propagation of vibrations, with one of the opposite surfaces thereof adjacent the thin film being greater than the other of said opposite surfaces.

Abstract: A piezoelectric vibrator adapted to operate in a spreading vibrating mode comprises compensation parts for compensating for the non-vibratory, or dead, region of a piezoelectric element which is formed between two confronting coupling pieces. The compensation parts comprise peripheral parts of the piezoelectric element that extend in an non-uniform manner from a center line passing through the respective centers of the confronting coupling pieces.

Abstract: In a piezoelectric vibrator capable of vibrating under an expansion mode of vibration, which has a piezoelectric vibrating element including a generally rectangular vibrateable substrate, made of a metallic material having a constant modulus of elasticity. The substrate is supported by a retaining member through a pair of connecting elements which extend outwardly from an arbitrarily chosen pair of side edges, respectively, so as to terminate in rigid connection with the retaining member. The width of each of the connecting elements as measured in a direction lengthwise of each of said edges is selected to be within the range of 1/7 to 1/3 of the length of said each side edge.

Abstract: An apparatus for measuring pressure within a conduit is disclosed preferably comprising a tube whose resonant frequency varies with the pressure of fluid within the tube; means for passing the fluid to be measured through the tube; two active piezoelectric films disposed in intimate contact with the tube on opposite sides thereof; first electronic means for energizing the first of the films to cause the tube to resonate at its natural frequency, and second electronic means connected to the other of the films to monitor the frequency of the tube.

Abstract: A flowmeter has a vane which is caused to vibrate at one of its resonant frequencies and a flexure standing wave set up along it. Two piezoelectric sensors are used to monitor characteristics of the standing wave and hence the mass flow rate of a fluid flowing past the vane along a pipe.The vane comprises a ceramic planar member on which a conductive ceramic ink is laid down to form tracks. The ink also bonds a ceramic piezoelectric transducer to the member to drive and maintain it in vibration. A non-conductive layer is laid down on the surface of the member covering the conductive tracks surrounding the transducer. A metal layer forms the external surface of the vane and acts as a ground plane for the transducer.

Abstract: A piezoelectric vibrator operating in a spreading vibration mode has a vibrating plate of permanently elastic metal. At least one main surface of the vibrating plate is mirror-finished.

Abstract: A shock absorbing mechanism for protecting a fragile quartz crystal includes a Teflon coating on the internal surface of the crystal enclosure. The enclosure is provided with a plurality of detents arranged so that when the crystal is shocked in its most fragile plane a plurality of these Teflon coated detents are struck simultaneously to distribute the shock across the surface of the crystal.

Abstract: A vibrating element for the vibration under an expansion mode has a substrate made of a constant modulus alloy and has a rectangular configuration defined by opposite long sides and opposite short sides, a thin piezoelectric film deposited on the substrate, and a vibration electrode film deposited on the piezoelectric film. When an equivalent circuit of the vibrating element can be defined as including a resonance inductance L, a resistance R and a series capacitance Cs, which are connected in series and a parallel capacitance Cp, which is connected parallelly to the series connection of L, R and Cs, a ratio of short side to long side of the substrate is selected to have values around points where a ratio of parallel capacitance Cp to serial capacitance Cs shows negative peaks.

Abstract: A torsional-mode resonator is produced by using an extensional mode transducer on a piece of material such as a metal bar where the transducer lies at an angle between the longitudinal axis of the material and the transverse axis. Placing the midpoint of the transducer at approximately the midpoint of the material such as the bar, optimizes the torsional effect. Further optimization may be obtained by making the transducer in the shape of a rhomboid.

Abstract: A mechanism for converting a weight into a frequency by means of a tuning fork vibrator having a pair of elongated plate-like vibrating strips extending in parallel with each other, a lever unit with a power pivot, fulcrum pivot and a load pivot, and a base portion, both ends of the tuning fork vibrator being coupled with the power pivot of the lever unit and the base portion, respectively by means of thin plate-like members. The weight to be converted is applied to the load pivot of the lever unit and is transferred to the tuning fork vibrator by means of the lever unit. All the parts of the mechanism are formed integrally from a single plate.

Abstract: Method and apparatus for detecting the presence of liquid in a container includes an elongate rod (or other vibratory element) which extends into the container to contact liquid when a certain amount of liquid is present, a piezo-electric element coupled to the rod on the exterior of the container to cause the rod to vibrate in response to electrical signals and to produce electrical signals indicative of the amplitude of vibration of the rod, and circuitry for producing a utilization signal when the electrical signals produced by the piezo-electric element indicate that the amplitude and duration of vibrations of the rod are below some threshold level. Such vibrations fall below the threshold level when the rod contacts liquid in the tank and so production of the utilization signal is an indication that liquid in the container has reached a certain level.

Abstract: The device is made by growing thin-film layers of materials on a silicon strate. These layers are then removed selectively by photolitographic masking and etching, to produce a pattern which is a series of cantilever plates which are piezoelectrically coupled. An electrical signal connected to a first pattern of piezoelectric material will cause the associated plate to deflect. A second piezoelectric pattern on each plate will generate an electrical signal due to the strain caused by deflection of the plate, and this signal is transferred to a first piezoelectric pattern on the next plate, and so on down to the last plate where the signal is extracted.

Abstract: A ceramic resonator including an elongated piezoelectric ceramic platelet having an indentation formed in the center in the longitudinal direction, a polarization in the thickness direction where the polarization occurs at least in the indentation; first and second main surfaces; first and third metal thin film electrodes formed on said first main surface and second and fourth metal thin film electrodes formed on said second main surface, the third electrode being separated from the first electrode and the fourth electrode separated from the second electrode where the resonator has a constant vibration based on the dimensions of the region associated with the indentation the vibration being generated at the narrow part when an electrical signal is applied to the electrodes. Moreover, a ceramic filter consisting of plurality of the ceramic resonators connected in series can also be configured.

Abstract: A method of fabricating an acoustic wave resonator wherein all processing steps are accomplished from a single side of said substrate. The method involves deposition of a multi-layered Al/AlN structure on a GaAs substrate followed by a series of fabrication steps to define a resonator from said composite. The resulting resonator comprises an AlN layer between two Al layers and another layer of AlN on an exterior of one of said Al layers.

Abstract: A piezoelectric resonator device with a laminated structure include two piezoelectric plates, each having opposite flat surfaces and polarized in a predetermined direction. Each piezoelectric plate is deposited with electrodes on its opposite flat surfaces, respectively. A junction layer of solder is rigidly held between the two piezoelectric plates for holding them together in a laminated structure. A weight ratio of the junction layer to a sum of two piezoelectric plates including their electrodes is selected to be between 0.5% and 5%.