Abstract: A surface acoustic wave (SAW) transducer comprises a piezoelectric substr, a pair of metal bus bars positioned on the substrate parallel to and separated from each other a preselected distance and a plurality of interdigital electrode fingers extending from each of the metal bus bars. A plurality of slots are positioned along each metal bus bar so that the bus bar metallization is reduced and the acoustic wave velocity is increased in the metal bus bar region.

Abstract: In a process of producing crystal resonators in which the direction and magnitude of the gamma vector is substantially the same for each resonator, a method of altering the resonator during the process to change the resonator mass, shape, or electrode placement so as to reduce the gamma vector magnitude of each crystal. This alteration may be done by adding mass, removing mass, or both adding and removing mass, or by positioning the electrodes to selectively position the electric field in the crystal, all in order to move the location of the active region of vibration and thereby reduce the gamma vector.

Abstract: A technique for adjusting the frequency of odd mode transverse waves propagating in a SAW device is described. A pair of localized regions of frequency determining trimming material are deposited onto selected portions of a surface wave propagating surface, to provide localized regions on said surface where the odd order transverse mode has energy maxima. These regions change the acoustic properties and hence the velocity characteristics of the surface wave propagating surface in said regions. The frequency of the odd mode transverse wave is changed accordingly and is preferably changed to match that of the fundamental transverse propagating wave. This decreases the insertion loss of the device at the fundamental frequency and eliminates the odd mode transverse wave propagation characteristic within the operating frequency range of the resonator.

Abstract: The present invention provides a substantially gauss-shaped sound field by means of an ultrasonic transducer, the potential on one side of the transducer being varied continuously by means of a thick-film electrode applied in a uniform or varying thickness. The thick-film can be a resistance paste or a conductive paste applicable in different thicknesses onto selected portions of the surface in question. The resistance paste can for instance be trimmed to different resistance values on selected portions of the surface. Such a technique makes it possible to alter the distribution of the potential so as to vary the distribution of the pressure in the sound field in such a manner that for instance a substantially gauss-shaped sound field is obtained.

Abstract: For the purpose of utilizing the characteristic in a vibration energy entrapping mode of a higher order symmetric or asymmetric mode vibration generated when a piezoelectric resonator is excited, there are provided a portion having a cutoff frequency f.sub.2 about an energy entrapping portion having a cutoff frequency f.sub.1 for strongly exciting a higher order symmetric or asymmetric mode vibration and at least one energy absorbing portion having a cutoff frequency f.sub.3 (at least f.sub.1 and f.sub.3 <f.sub.2). The size of the energy entrapping portion (electrode), amount of plateback (f.sub.2 -f.sub.1)/f.sub.

Abstract: A monolithic coupled-dual resonator crystal filter is produced for operation with wide bandwidths (especially at high center frequencies) by providing an ultra-small gap between juxtaposed resonator electrodes. A gap width of substantially less than 0.006 inch is obtained by laser-machine trimming the gap. An initial single electrode may thus be divided into a pair of such juxtaposed resonator electrodes. Further metallic plate-back is provided on the electrodes for center-frequency control. Although this typically may decrease the coupling bandwidth somewhat, an increased thickness of metallic plate-back material on the ground electrode, opposite the ultra-thin gap area on the active side of the crystal wafer, provides precisely controlled extra wide bandwidth.

Abstract: A surface acoustic wave resonator comprising at least two interdigital electro-acoustic transducers found between two sets of reflective gratings on a crystalline substrate. The period of the electrodes of the transducers is selected to be less than the period of the reflective gratings.

Abstract: Crystal resonator with low acceleration sensitivity includes a piezoelectric quartz crystal, support structure for holding the crystal and a signal source for causing the crystal to resonate with an active region of vibration. The resonator is modified, if need be, to control (generally reduce) the gamma vector which is a measure of the acceleration senstivity. This may be done by adding mass, removing mass, or both adding and removing mass, all in order to move or change the shape of the active region of vibration and thereby reduce the gamma vector.

Abstract: Sonic transducer and method for making the same. A sonic transducer of the type used in generating ultrasound frequencies for medical therapy includes a substantially planar circular piezoelectric crystal which is bonded to the rear surface of a circular metal diaphragm. The diaphragm front surface includes a substantially planar applicating face and an annular non-parallel surface surrounding the applicating face. The transducer may be excited to produce maximum ultrasound energy over a relatively broad frequency range.

Abstract: An ultrasonic vibrator comprises torsional electrostrictive transducers for torsional vibration, longitudinal electrostrictive transducers for longitudinal vibration, and two metallic members firmly, coaxially and integrally holding the torsional electrostrictive transducers and the longitudinal electrostrictive transducers therebetween. An altered section is formed in one of the metallic members in such a shape that makes the torsional resonant frequency and the longitudinal resonant frequency coincide with each other. A voltage or an electric current having a controlled amplitude and/or a controlled relative phase is applied to the electrostrictive transducers to generate composite vibrations of various modes.

Abstract: A piezoelectric coupled mode turning fork using the fundamental vibration of a flexural mode coupled with the fundamental mode of torsion. The fundamental frequency of the torsional mode is adjusted by masses near the side edges of the tine tips, and the fundamental frequency of the flexural mode being adjusted by masses near the center of the tine tips which are nodes of the fundamental torsional mode.

Abstract: An improved gas density transducer which compares the resonant frequency of an enclosed, reference tuning fork crystal oscillator with the resonant frequency of a detector tuning fork crystal oscillator exposed to the surrounding gas. The frequency of oscillation of the detector crystal oscillator exposed will vary in accordance with the gas density because of the motional resistance of the gas to vibrations of the tuning fork oscillator. The frequency of the detector oscillator can be compared to the frequency of the reference oscillator to determine the gas density.

Abstract: A low aging piezoelectric resonator is made from a plate of piezoelectric terial using standard resonator fabrication techniques with identical electrodes applied to both major faces of the plate; the electroded plate mounted in a suitable enclosure and the unit vacuum baked and sealed under high vacuum to remove as much contamination as possible, and a DC voltage impressed between the resonator electrodes and the enclosure to create a static electric filed within the enclosure.

Abstract: A double resonator beam force transducer configured to minimize longitudinal pumping by making the beams vibrate symmetrically. This can be accomplished by making the boundary conditions of the beams symmetrical or, if the boundary conditions are nonsymmetric, then by biasing the beams inwardly or outwardly to compensate for the nonsymmetrical boundary conditions of the beams. In the nonsymmetrical case where the beams would bow outwardly at their fundamental resonant frequency or an odd overtone thereof, an inward bias is provided to minimize longitudinal pumping. In the nonsymmetrical case where the beams would bow inwardly at an even overtone of the fundamental resonant frequency, an outward bias is provided to minimize longitudinal pumping.

Abstract: A piezoelectric vibrator of thickness-shear mode including a vibrating plate made of AT-cut quartz and a pair of electrodes applied on major surfaces of the vibrating plate in opposition to each other. A part of a contour of the vibrating plate is made closer to the electrode by cutting off a corner of a square vibrating plate. An impedance of the piezoelectric vibrator for a fundamental vibration is extremely increased to suppress the fundamental vibration and thus the piezoelectric vibrator can vibrate stably at a third overtone frequency.

Abstract: SC cut crystal resonators having lateral field excitation are disclosed. An SC cut quartz crystal blank is a doubly rotated Y cut which has the very valuable characteristic that its resonance frequency is stable while under stress, either from temperature gradients or from shock and vibration. Because of the threefold symmetry of quartz, and since the SC cut is rotated 22 degrees about the Z axis, there is a Y axis only about 8 degrees from the surface of an SC cut plate. A lateral field directed along or near this axis strongly excites the C mode and very weakly excites the B mode, if at all. The electrodes generating the lateral field are placed on the same major surface of an SC cut quartz crystal disc element and shaped to place the strongest field in the center of the disc element. This has been found to strongly couple to the C mode and suppress all other modes including the B mode and satellite C modes. Spectral purity and Q are enhanced thereby.

Abstract: Surface wave filter with a slab-shaped substrate of monocrystalline piezoelectric material, particularly lithium niobate, having input and output transducers optionally coupled by means of a coupler on one substrate side. A plastic and/or elastic damping layer are applied for suppressing reflected waves. The damping layer covers at least in some regions, this substrate side except for the area which is bounded by the transducers, the coupler, the ends of the conductor runs and the regions between the transducers and the coupler. The end face edge of the damping layer increases at least in sections, gradually from zero to the value of the layer thickness.

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: A vibrating beam force transducer includes a piezoelectric beam structure supported at first and second ends, and an oscillator for inducing a vibration in the piezoelectric beam. To permit adjusting the bias frequency of the beam, an adjustment mass is formed at the center of the beam, the adjustment mass made of piezoelectric material. Part of the adjustment mass can be broken off to adjust the bias frequency. The first and second ends are attached to the a support structure by first and second legs at each end of the beam, the legs having an angle therebetween, thereby forming an A-frame mount.

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 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: An improved method of adjusting piezoelectric devices to frequency by particularized laser trimming is disclosed. The laser removes a single contiguous area in the center of the electrodes to appropriately increase the individual resonator frequency without significantly degrading the filter "Q". In an AT-cut monolithic crystal filter, the particularized laser trimmed area can be positioned such on the face of the electrodes to simultaneously control frequency and bandwidth. This method can be substituted for the more cumbersome process of frequency adjustment by vapor deposition to provide a rapid inexpensive technique for monolithic crystal filter manufacture.

Abstract: A piezoelectric resonator including a piezoelectric substrate of a quadrilateral or rectangular configuration, and electrode layers provided over opposite main faces of the piezoelectric substrate for vibration of the piezoelectric substrate on the whole, and characterized in that the piezoelectric substrate is formed, in its four side edges, with notched portions having dimensions and shapes different from each other.

Abstract: A resonator having a desired frequency is made from a quartz crystal resonator plate by a method including the steps of:(A) etching the quartz crystal resonator plate to a frequency slightly higher than the desired frequency,(B) vacuum desposting metallic electrodes onto the active area of the resonator plate to lower the frequency to a frequency that very closely approaches the desired frequency, and(C) treating the plate with the deposited electrodes with UV-ozone to oxidize the electrodes in a slow, precisely controlled manner to the desired frequency.

Abstract: A piezo-electric transducer includes a piezo-electric ceramic sheet bonded to a vibrating reed and one or more electrodes bonded to the piezo-electric ceramic sheet, wherein said vibrating reed has a plurality of through-holes on a vibrational nodal line for vibration of the vibrating reed.

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: 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: An improved crystal plating device having a base containing a power circuit and an oscillating circuit. The base is provided with a chamber and has a sealed top enclosing the chamber. At least one pair of filament posts are fixed to the base and disposed within the chamber and in the power circuit. A filament is connected across the filament post. A crystal holder is removably connected with the base. The crystal is held by the holder in the oscillating circuit. A pump is connected to the base to vacuum pump the chamber. Energizing the circuits will oscillate the crystal and evaporate the filament to plate the crystal and produce the desired frequency therefore. The improvement comprises a crystal holder designed to hold a plug-in circuit board having a plurality of prongs, the board containing the crystal. The crystal holder includes plug-in means for inserting the prongs of the circuit board in the oscillating circuit.

Abstract: A process for adjusting the frequency of a resonator by bursts of laser beam shots which pierce successive lines or holes in a metal coating deposited on the resonator. The amount of material removed by a burst of shots varies in the course of the operating procedure so that the frequency of the resonator is adjusted towards the desired frequency by successive approximations. After each burst of shots, the frequency of the resonator is compared to a provisional limit frequency. The amount of material removed in the following line and the provisional limit frequency are changed or left unaltered, depending on the result of the comparison.

Abstract: A method for batch-contouring crystal plates for frequency adjustment is disclosed. A plurality of plates is secured to a compliant sheet and the sheet is attached to an applicator surface which includes a resilient pad. The plates are then abraded against another surface to produce contours on all the plates. The resilient pad provides spring loading to insure uniform pressure on all the plates.

Abstract: An improved crystal plating device having a base containing a power circuit and an oscillating circuit. The base is provided with a chamber and has a sealed top enclosing the chamber. At least one pair of filament posts are fixed to the base and disposed within the chamber and in the power circuit. A filament is connected across the filament posts. A crystal holder is removably connected with the base. The crystal is held by the holder in the oscillating circuit. A pump is connected to the base to vacuum pump the chamber. Energizing the circuits will oscillate the crystal and evaporate the filament to plate the crystal and produce the desired frequency therefore.Filament posts each comprising a hollow body having an insulating sleeve thereon are threadedly received on a member affixed to the base. A slot is provided in the body near the upper end with a spring biased pivotable lever, the filament being disposed within the slot.

Abstract: The high-frequency piezoelectric resonator comprises a quartz plate or disk having a region of reduced thickness which forms a diaphragm and is joined to the remainder of the plate or disk by means of a zone forming a step. A conductive electrode extends from the exterior of the disk or plate to the center of the thinned region and is provided with a conductive tongue constituted by a metallic film-layer of controlled thickness and disposed in the stepped zone. The method involves formation of the disk or plate by ion machining whereas the electrodes and the conductive tongue are formed by the sputtering technique.

Abstract: The pressure sensitive element described has an improved barometric coefficient. The sensitive element essentially consists of a piezoelectric tuning fork having a base and a pair of arms. At the end of each arm are provided slots that are parallel to the flanks of the arms. The slots extend all the way through the thickness of the arms. The sensitive element is particularly suited for use in gas pressure measuring sensors.

Abstract: A method for manufacturing a compound accelerometer that is maximally sensitive to a desired acceleration vector to the exclusion of orthogonal vectors. The compound accelerometer is made by combining two simple accelerometer units. The simple accelerometer units consist of a hollow container closed at each end by a piezo-electric transducer. The two transducers are oppositely polarized and are selected to have a desired combined series capacitance value. The container is partially filled with a volume of heavy liquid and the accelerometer is excited. During excitation, the output voltage is continuously measured and the volume of liquid is microadjusted until the output voltage equals a prescribed level. The outputs of the individual transducers are measured, the residual voltage difference is tabulated and the dominant transducer is identified.

Abstract: In the manufacture of surface acoustic wave devices it is necessary to manufacture master patterns from which interdigitated electrodes are produced photographically. The manufacture of the master is expensive and a new master is needed for each new device required to operate at a different frequency. The invention overcomes this problem in the device shown in FIG. 1 by the use of transducers 2 and 5, each constituted by separate groups 3 or 6 of interdigitated fingers. The effect of this is for the transducer to have peak frequency responses at a whole series of frequency values. These frequency values can be shifted up or down by varying the velocity of the surface acoustic waves in the region of the appropriate transducer. This is done using any one of a number of different methods but, in the embodiment of FIG. 1, metal layers 8 and 9 are applied and then adjusted in size until a peak of the transducer 2 coincides, at the desired frequency, with a peak of the transducer 5.

Abstract: A tuning fork utilizing elastic coupling between the flexural mode and the torsional mode in which the frequency of the flexural mode is adjusted by adding or reducing masses deposited near the center of the arms in the lengthwise direction and the frequency of the torsional mode is adjusted by adding or reducing masses deposited on the other portions such as the tops of the arms. The positions near the center of the arms in the lengthwise direction are suitably selected so that adding or reducing the masses thereto or therefrom changes only the frequency of the flexural mode changes only and the frequency of the torsional mode is scarcely changed.

Abstract: Each resonant frequency of a coupling resonator is measured at a plurality of each different temperatures. From these values the first order temperature coefficient .alpha. is calculated. According to the value of .alpha., it is accurately adjusted and finally the resonant frequency of a fundamental vibration is also adjusted to a nominal frequency.

Abstract: An improved crystal is provided with an aluminum baseplate, a nickel plating on the aluminum baseplate, and a silver plating on the nickel plating. The nickel is plated on the aluminum baseplate before the aluminum has oxidized to provide high yields of stable crystals.

Abstract: A piezoelectric tuning fork vibrator used as an oscillator or a detection element in various electronic circuits, which is provided at a vibrator body with a slit to form tuning fork legs at both sides, one leg at the vibrator having at the outside surface a piezoelectric thin film and an electrode thereon, so that the one leg including the piezoelectric thin film and electrode, is made equal in width to the other leg.Hence, the both side tuning fork legs equal in width become equal in the resonance frequency and avoids leakage of vibration energy, whereby this piezoelectric vibrator is free from characteristic variation and has a high accuracy.

Abstract: A piezoelectric resonator chip which includes a piezoelectric chip plate and a pair of electrode patterns which is formed on the opposite surfaces of the piezoelectric chip plate, the electrode patterns face each other through the piezoelectric chip plate. At least one of the electrode patterns has an adjuster pattern which includes a narrow cutting pattern and a separation pattern which is connected to the electrode pattern through the cutting pattern and which faces the other electrode pattern.

Abstract: If a piezoelectric crystal is used in circuits containing ICs with low supply voltage, the additional capacitors required in oscillator or filter circuits cannot be implemented as junction capacitances. To eliminate the need for additional discrete capacitors, these capacitances are implemented with additional films on the crystal.

Abstract: A dual-transducer accelerometer, having a liquid inertia mass is disclosed. Each transducer consists of a ceramic PZT piezo-electric wafer glued to a flexible substrate. Certain characteristics of sensitivity and capacitance of one transducer can be matched to similar characteristics of an arbitrarily-selected standard by laser-trimming the ceramic wafer.

Abstract: A method for adjusting the frequency of a piezoelectic resonator such as a quartz crystal is disclosed. The resonator is placed within its enclosure facing a metallic surface. The atmosphere within the enclosure is made suitable for supporting a glow discharge. An electrical potential is then established between the resonator electrode and the metallic surface causing mass to sputter between the electrode and to the metallic surface to vary the characteristics of the resonator.

Abstract: The acceleration sensitivity of an AT-cut quartz crystal plate resonator is educed by replacing the quartz crystal plate of the resonator with a quartz crystal plate having a flatter plate contour.

Abstract: The GT-cut quartz resonator resonated by two longitudinal modes and provided with the masses for frequency-temperature characteristics adjustment and frequency adjustment. The frequency-temperature characteristics and the frequency of the GT-cut quartz resonator are adjusted by eliminating the masses. Consequently, the quartz resonator adjusted to the normal frequency and having the excellent frequency-temperature characteristics is attained. Further the GT-cut quartz resonator of small and thin size is attained by making the resonant portion and the supporting portions in one piece by photolithographic technique.

Abstract: A GT-cut quartz resonator mounted on a pedestal is disclosed. The pedestal has a plural though holes on a predetermined positions. The frequency and the frequency-temperature characteristics of the GT-cut quartz resonator are easily adjusted by depositing masses on the resonator by evaporation and sputtering through the through holes on the pedestal.

Abstract: Surface acoustic wave devices with precisely set frequencies are produced by laser trimming metallization strips on the device while monitoring the device frequency and/or phase shift. The trimming strips may be metallizations added during device manufacture or after device manufacture, or they may include selected ones of the reflecting gratings.

Abstract: A miniaturized face-shear mode quartz crystal vibrator and method of manufacture is provided. The vibrator is formed from a Y-cut quartz crystal plate less than 500 .mu.m thick which has been rotated between 45.degree. to 55.degree. about the X-axis. A plurality of vibrators are formed by depositing a thin metallic film on the two opposed planar surfaces of the plate, selectively etching portions of the metallic films and dissolving the uncoated portions of the plate. The metallic films become the vibrator electrode.

Abstract: For regulating the vibration frequency of a tuning-fork vibrator to a desired frequency, the tuning-fork vibrator is regulated so that its vibration frequency may become a frequency lower than the desired frequency by a predetermined value, and then the tuning-fork vibrator is regulated so that a difference between proper vibration frequencies of both legs of the vibrator may become smaller than a predetermined value, and further, the vibrator is regulated so that the desired frequency may be reached, while maintaining the difference in the proper vibration frequency smaller than the predetermined value. In this way, the desired frequency can rapidly be attained.

Abstract: Disc shaped quartz crystal resonators of plano-convex, plano-plano, and bnvex configurations have the b-mode resistance raised relative to the c-mode resistance by the proper choice of mounting geometry, thus suppressing the undesired b-mode in precision oscillator circuits without the use of added circuitry.