Abstract: In a crystal element of the type wherein a DT-cut crystal element is used to generate vibrations of the contour mode, one side of the crystal element is flat and the thickness of the element is gradually decreased from the center toward the periphery thereof.

Abstract: An electro-acoustic transducer with a piezoelectric diaphragm which is backed with a plurality of different resilient members for imparting a suitable resiliency and/or tension to said diaphragm to highly improve its acoustic characteristics with a simple construction.

Abstract: An elastic surface wave apparatus, wherein transmission and reception electrode pairs for conversion of electric signals into elastic surface waves are spatially disposed so as to cause said surface waves to be propagated over the X-Z axis surface of a Y-cut lithium niobate (LiNbO.sub.3) piezoelectric element in a direction inclined 0.5 to 7 degrees relative to the Z axis.

Abstract: A crystal resonator is disclosed of a single crystal of the approximate composition Tl.sub.3 BX.sub.4 having two parallel surfaces normal to a zero temperature coefficient of frequency direction and having an electrode mounted on each surface, where B is vanadium, niobium, or tantalum, and X is sulfur or selenium. A filter is disclosed of a crystal resonator coupled to a capacitor or more than one crystal resonator in series each coupled to a capacitor. A voltage controlled crystal oscillator resonator is disclosed of a crystal resonator in parallel with an inductor and a varactor.

Abstract: A piezoelectric electro-acoustic transducer employing as a diaphragm a uniaxially stretched film of a shape having the major axis and the minor axis, wherein the expansion-contraction direction of the diaphragm, in which a piezoelectric constant is at a maximum, is substantially in parallel with the minor axis thereof, whereby the piezoelectric electro-acoustic transducer can provide a high converting efficiency, especially in the low frequency range.

Abstract: An ultrasonic transducer comprising a linear array of piezoelectric elements for converting a single line from a compressional acoustic image field to electrical impulses which, in turn, provide a means for converting the incident compressional image field to a visual representation. In order to match the configuration of the acoustic image field, the array of piezoelectric elements, in a preferred embodiment, has the configuration of an arc, that is, the array is arranged in a straight line in one plane and in an arc in a plane orthogonal to the first. The transducer is made up of a plurality of assemblies each of which is composed of segments of piezoelectric material each held in a supporting slot in a length of metal plate which slot is filled with a material selected to provide impedance matching between the piezoelectric material and the transmission medium.

Abstract: A flexural mode quartz crystal vibrator formed from a quartz crystal plate having first and second opposed substantially planar surfaces, with a plurality of electrodes on at least one side thereof, is provided. The vibrator is characterized by the placement of electrodes on at least one of the opposed surfaces of the quartz crystal plate, the placement of the electrodes providing a vibrator having a thickness of 0.5 mm or less.

Abstract: The present invention relates to electromechanical resonance devices comprising a piezo-electric crystalline plate and electrodes arranged opposite one another upon the principal faces of said plate. In accordance with the invention, the piezo-electric wafer is cut from a lithium niobate crystal, in accordance with the Y + 37.degree. cut.

Abstract: The disclosure relates to an acoustic surface wave device and method for long signal delays and bulk wave discrimination through the folding of a surface wave propagation path. A surface wave device is formed on the surface of an acoustic substrate and a surface wave, acoustic discontinuity is formed in the propagation path of surface waves propagated along the surface of the substrate. The acoustic discontinuity defines a reflecting surface for acoustic surface waves thereby deflecting incident surface waves along a reflecting path differing from the propagation path. Substantially all of the bulk waves propagated along the propagation path continue along this path and can be absorbed or otherwise dissipated. As a result, a substantially pure surface wave mode signal can be detected along the reflecting path. The surface waves may be reflected in this manner, i.e., by folding the path of the surface waves, a number of times as required to obtain a desired delay.

Abstract: A temperature compensated surface acoustic wave device having an SiO.sub.2 film layer upon a substrate of piezoelectric material. The positive temperature coefficient of delay of the piezoelectric substrate is counterbalanced by the negative temperature coefficient of the SiO.sub.2 layer. The thickness and shape of the SiO.sub.2 layer are chosen to give a zero first order temperature coefficient for the composite device. Lithium niobate and lithium tantalate are preferred piezoelectric materials for the substrate. A high degree of temperature stability is thereby obtained with coupling coefficients much greater than were previously obtained by prior temperature compensated surface acoustic wave devices.

Abstract: The invention relates to the directive transmission of elastic surface waves. The object of the invention is a device comprising a crystalline substrate on whose surface elastic surfaces waves can be propagated. The value of surface-wave phase velocity can be changed by local modification of the crystalline lattice structure in a directive zone formed immediately below the surface. The structural modification of the lattice structure can be produced by ion implantation.

Abstract: A piezoelectric device comprisng a thin plate of a piezoelectric material which has a Poisson's ratio of less than one-third, and has an electrode region and a non-electrode region, wherein the thickness relation between the electode region and the non-electrode region is arranged so that the thickness of the electrode region is smaller than the thickness of the non-electrode region when a value of equations represented by (.pi.p/4)+(4/k.sup.3)cot(.pi.kp/2) Q for the thickness-extensional mode, and (.pi.q/4)+(4/k)cot(.pi. q/2k) Q for the thickness-shear mode is negative respectively for a desired vibratory mode, and that the thickness of the electrode region is larger than the thickness of the non-electrode region when the value of the above equations are positive respectively for a desired thickness vibration mode.

Abstract: A method for control monitoring the phase, depth, and area polarization of a piezoelectric transducer element. A piezoelectric element is energized by electrical pulses of controlled amplitude, duration, and repetition rate, and the response of the element is recorded by an oscilloscope or other suitable device. By properly matching the configuration, duration, and repetition rate of the driving pulses, with respect to the desired depth and phase of individual element layers, controlled-phase controlled-volume transducers may be achieved with a single piezoelectric transducer element.

Abstract: An acoustic surface wave filter comprising a monocrystalline wafer of bismuth silicon oxide having a special orientation of the ASW propagation surface and the interdigital transducers relative to the crystal plane whereby pick-up of undesired bulk waves is reduced.

Abstract: A .theta.-rotated Y-cut X-propagating piezoelectric substrate of crystalline lithium niobate for use in an elastic surface wave device, wherein the angle .theta. at which the substrate is cut out is chosen to range between 125.6.degree. and 130.1.degree. to suppress spurious wave components.

Abstract: Crystals or Tl.sub.3 VS.sub.4, Tl.sub.3 VSe.sub.4, Tl.sub.3 NbS.sub.4, Tl.sub.3 NbSe.sub.4, Tl.sub.3 TaS.sub.4, and Tl.sub.3 TaSe.sub.4 are disclosed which have a surface containing of normal to a zero temperature coefficient of delay direction. The crystals are used to transmit acoustic waves in surface and bulk wave devices.

Abstract: An insulating substrate, on which is at least one single crystalline electrode and a single crystalline layer of piezoelectric material on the electrode, forms an efficient surface acoustic wave device.

Abstract: Spurious modes related to the slow shear mode in an X-cut lithium tantalate crystal are suppressed and/or eliminated by reducing the ratio of plate dimension along the slow shear direction (y') to the dimension along the X direction. Undesired modes associated with the flexural family of modes can be separated in frequency from the desired, fast shear mode by the "proper" ratio of plate dimension along the fast shear direction (z') to the dimension along the X axis.

Abstract: A method for obtaining controlled depth, controlled area, and controlled phase polarization of a piezoelectric transducer element. A controlled phase bias voltage is applied to two generally opposing surfaces of the transducer element, and heat is then applied in a pulsed fashion to one of the two surfaces. By properly coordinating the phase of the bias voltage and the pulsed heating of the one surface, discrete layers of polarization may be created between the two surfaces, the phase, area and depth of the discrete layers being accurately controllable.

Abstract: A piezoelectric-type electroacoustic transducer composed of two convex or concave piezoelectric polymer films each having electrodes on both surfaces thereof, said two polymer films being so connected to electric wiring that, when the one of the piezoelectric polymer films elongates by the action of an electric field in one direction, the other shrinks by the action of the same electric field.

Abstract: A ferroelectric surface wave transducer device comprising an unpoled ferroelectric substrate having a substantially sinusoidal poled region at a surface thereof. A metal plate electrode is disposed on the opposing surface of the substrate. In operation an A.C. voltage applied across the two electrodes gives rise to a surface elastic wave in the substrate. Also disclosed is a method of producing a surface wave transducer of the type described. A pair of interdigitated metal electrodes are applied to a surface of an unpoled ferroelectric substrate. A poling potential is applied between the electrodes, preferably while the substrate is heated. The interdigitated electrodes are then removed and a metal plate electrode is applied over the region where the interdigitated electrodes had been. Finally, another metal electrode is applied to the opposite surface of the substrate. In a preferred embodiment of the invention the interdigitated electrodes are in the form of a moveable fixture.

Abstract: A device for generating or sensing transverse elastic bulk waves in solids includes a piezoelectric material engaging a surface of the solid and having a two-fold axis or equivalent symmetry extending parallel to the surface of the solid. A pair of electrodes are located on a surface of the transducer extending perpendicular to the surface of the solid which the material contacts. Each electrode has one or more conductive fingers elongated in a direction parallel to the two-fold axis of the material. The fingers of the electrodes are interlaced. When used as a generator of bulk waves, a source of alternating voltage excites the electrodes. The electrodes thus generate deep surface waves in the piezoelectric material which are transformed into bulk waves in the test solid. Similarly, bulk waves in the test solid are transformed into deep surface waves in the piezoelectric material which may then be sensed by the electrodes.

Abstract: A flexural mode quartz crystal vibrator formed from a quartz crystal plate having first and second opposed substantially planar surfaces, with a plurality of electrodes on both said surfaces is provided. The vibrator is characterized by the placement of electrodes on both of the opposed surfaces so that the electrodes on each surface do not overlap each other.

Abstract: A surface acoustic wave (SAW) structure is disclosed wherein a SAW device is incorporated as an exterior lamina within a composite laminate in order to temperature stabilize the acoustic device. The composite laminate is synthesized to selectively mismatch the thermal expansion characteristics of the piezoelectric material, which is the body of the acoustic device, along the axis of acoustic propagation and simultaneously approximately match the thermal expansion properties along the orthogonal axis. Compressive force is thereby applied to the acoustic device to keep the substrate length constant and thus provide an approximately zero temperature coefficient over a preferred range of temperatures.

Abstract: Process for the production of a piezoelectric body which contains a ferroelectric material which may be polarized in an aligned, permanent fashion and also contains a bonding material, the process comprises mixing a bonding material selected so that at least in a temperature range below the Curie temperature of the ferroelectric material, it has a specific electric conductivity .sigma..sub.B > E.sub.C .times. .sigma..sub.K /E.sub.B, where .sigma..sub.K is the specific conductivity of the ferroelectric material, E.sub.C is the coercivity field strength of the ferroelectric material, and E.sub.

Abstract: A thin film piezoelectric transducer generates bulk mode ultrasonic elastic waves which propagate into a transmission medium, such as silicon. The wave is reflected back towards the first transducer by a reflecting surface. A second transducer is located adjacent to the first transducer and receives the acoustic wave from the reflected surface. The path length of the ultrasonic wave from the first transducer to the second transducer is long enough to enable the bulk wave to be in the Fraunhofer field. An acoustic absorbing material, such as indium, may be placed on the reflecting surface and on the surface containing the two transducers in selective areas to reduce undesired reflections. The structure is suitable for use in the microwave region wherein the insertion loss may be relatively constant over a given frequency band.

Abstract: A key input device which forms a key switch with high reliability or an integrated keyboard with small dimensions which can produce coded signals with high reliability and a S/N ratio of high value without any encoder circuits, comprising a piezoelectric polymer film, applied as a pressure sensor, having layer electrodes on both surfaces thereof and at least one device for straining the film, the straining device defining a key.

Abstract: An acoustic surface wave device is disclosed which comprises a crystal of Tl.sub.3 TaS.sub.4, Tl.sub.3 TaSe.sub.4, or mixtures thereof having at least one surface suitable for the propagation of surface waves, a surface wave generating transducer mounted on the surface, and a surface wave receiving transducer mounted on the surface positioned to receive a surface wave generated by the surface wave generating transducer.The device transmits surface waves at a low velocity and high coupling efficiency and can be used in a delay line, a filter, an FM discriminator, an oscillator, or other device.

Abstract: The disclosure is directed to a method for processing quartz used in fabricating crystal resonators such that transient frequency change of resonators exposed to pulse irradiation is virtually eliminated. The method involves heating the crystal quartz in a hydrogen-free atmosphere while simultaneously applying an electric field in the Z-axis direction of the crystal. The electric field is maintained during the cool-down phase of the process.