Abstract: An ultrasound transducer for use in an ultrasound visualization and therapy system or the like. The ultrasound transducer is characterized as a single crystal transducer having a radiating surface which conforms generally in shape to a segment of a surface of a solid of revolution of a conic section, the radiating surface having first and second edges which are generally parallel.

Abstract: Disclosed is a surface-acoustic-wave convolver having a toroidal coil connected to each interdigital electrode as a matching and balanced-to-unbalanced converting circuit. The use of the toroidal coil wound on an associated toroidal core permits the reduction of required parts in number thanks to its dual function, and accordingly reduction of manufacturing cost and size of the device. Still advantageously the use of such a toroidal winding permits the suppression of spurious or noise signals in an SAW device.

Abstract: A surface acoustic wave device is disclosed, by which it is possible to improve characteristics of a system suitable for suppressing narrow frequency band interference, which is useful for a spread spectrum communication system, and to increase the signal intensity at the detecting portion without changing characteristics of the filter portion.In a surface acoustic wave element, in a p conductivity type Si epitaxial layer 2 formed on a p+ conductivity type Si monocrystal substrate 1 the epitaxial layer on the siganl detecting portion is formed so as to be thinner than the other portion by means of a buried layer.In this way, even with a same intensity of the input signal at the transducer, the loss of SAW is reduced and as the result the intensity of the detected signal is increased.By the present invention it is possible to increase the signal intensity at the detecting portion without changing characteristics of the filter portion.

Abstract: An SAW convolver having a piezoelectric film / insulating layer / low impurity concentration Si epitaxial layer / high impurity concentration Si epitaxial layer structure is disclosed, in which the low impurity concentration Si epitaxial layer is replaced by a GaAs epitaxial layer. In this way, it is possible to improve concentration characteristics with respect to those obtained by the prior art structure described above and it is unnecessary to control the thickness of the epitaxial layer so strictly as for the prior art structure.

Abstract: A Lithium Tantalate crystal, defined by the Euler angles lambda (.lambda.) equal to about 0.degree. and mu (.mu.) equal to about 90.degree. with an acoustic wave propagation direction angle theta (.theta.) in the range of plus 130.degree. to plus 150.degree. and preferably equal to about plus 141.25.degree., offers unique properties for surface acoustic wave device applications.

Abstract: In a wide band surface acoustic wave filter having a multilayered structure, in which an elastic substrate and a piezoelectric thin film are combined, transducers are so constructed that the period of electrodes thereof varies in the direction perpendicular to the propagation direction of the surface acoustic wave.

Abstract: A surface accoustic wave device includes a substrate which is made up of single-crystalline dielectric member and a piezoelectric thin film epitaxially grown thereon. An aluminum electrode defining an interdigital electrode is formed along the interface between the dielectric member and the piezoelectric thin film. This aluminum electrode is formed of an aluminum film which is crystallographically oriented in a constant direction, whereby stressmigration of the aluminum electrode is suppressed, while enabling epitaxial growth of the piezoelectric thin film over the entire surface insert.

Abstract: A surface acoustic wave device comprising a single crystal silicon substrate and a piezoelectric thin film of single crystal or C-axis-oriented polycrystalline aluminum nitride formed on the surface of the substrate. The C-axis of the piezoelectric thin film is set in a direction in which the projection vector of the C-axis on a plane containing the axis of propagation direction of a surface acoustic wave and a normal axis of the substrate makes an inclination angle .theta. of up to 60 degrees with the axis of propagation direction, whereby the device is given a coupling coefficient of at least 2% is given as maximum coupling coefficient of the device.

Abstract: A surface acoustic wave device having interdigitated transducers comprised of an improved metalization system including copper and titanium doped aluminum transducers. A method of producing the interdigitated transducers includes deposition of the metals on a quartz substrate and subsequent heat treatment. The metalization system provides SAW devices having improved long-term frequency stability, particularly when operated at high power levels. The surface acoustic wave device may be incorporated in a feedback loop of an amplifier to form an oscillator circuit.

Abstract: A SAW transducer eliminates mechanical energy reflections by using one-quarter wavelength electrodes spaced at predetermined intervals. Dummy electrodes are shifted one-quarter wavelength to cancel energy reflections in the active electrodes. A pair of dummy electrodes is required for each active set of electrodes (the active set comprises one positive and two negative electrodes).

Abstract: An acoustic surface wave element having an oscillation frequency stable against temperature changes, and a wide range of oscillation frequency adjustment, is provided by an acoustic surface wave element comprising: a substrate of a 36.degree. rotated Y-cut single crystal lithium tantalate having X, Y and Z crystal axes and a top surface and side walls; electrodes formed on the top surface of the substrate such that an acoustic surface wave is propagated in a direction of the X-axis of the substrate and an oscillation of the acoustic surface wave occurs at a predetermined frequency, the electrodes having a thickness equal to 1 to 4% of a wavelength of the acoustic surface wave at the oscillation; and a plasma CVD-deposited layer of silicon dioxide covering the electrodes and the substrate, the silicon dioxide layer having a refractive index of 1.445 to 1.486 and a thickness equal to 16 to 26% of the wavelength of the acoustic surface wave at the oscillation.

Abstract: In a SAW convolver having a multi-layer structure consisting of a piezoelectric layer, insulation layer and semiconductor layer and having at least one combshaped electrode fed with an input signal and a gate electrode for exerting a convolution output, an interface in the form of a jaggedness is formed between the insulation layer and the semiconductor layer to improve the convolution efficiency.

Abstract: A surface acoustic wave device which comprises a piezoelectric layer, a carbonaceous layer which is selected from the group consisting of a diamond layer and a diamond-like carbon layer and formed on at least one surface of the piezoelectric layer, and at least a pair of interdigital transducer electrodes, can be used in an extremely high frequency region.

Abstract: In a surface acoustic wave element comprising a semiconductor substrate, a piezoelectric layer formed thereon and at least one interdigital electrode disposed on the surface thereof, a semiconductor region having a conductivity type different from that of the semiconductor substrate is disposed on the outer side of the interdigital electrode just below the piezoelectric layer.

Abstract: A solid state electronic device having a thin film of an Al (aluminum) alloy Li (lithium) on the surface of a substrate for a surface acoustic wave (SAW). Interdigital electrodes, electric wiring patterns and bonding pads are formed by the thin film of the Li-added Al alloy. This thin film suppresses migration which occurs when a high density current is supplied to the device or a large amplitude SAW is generated. The thin film, which provides a small loss and relatively low hardness, provides a desired power handling capability and high yield of wire bonding. The this film assures high endurance to failure of the device and sufficient life of the device.

Abstract: A SAW convolver is disclosed, in which an auxiliary electrode is disposed between the gate electrode and each of two input electrodes and self convolution is reduced by applying to the auxiliary electrodes such a bias voltage that the portion of the semiconductor layer below each auxiliary electrode is inverted.

Abstract: A novel heterojunction acoustic charge transport device (HACT) includes a modulation doped field effect transistor (MODFET) on the same substrate. The device is characterized by a sequence of epitaxial layers such that the MODFET is fabricated in a first portion of the uppermost layers while the HACT device is fabricated in an adjacent second portion using a partially overlapping subset of the lower layers after selected upper ones have been removed to form a single integrated electro-acoustic device.

Abstract: A surface-acoustic-wave device includes a glassy layer provided on a piezoelectric layer and having periodic grooves (gratings) so as to be used as a reflector exhibiting an excellent reflection ratio.

Abstract: A surface acoustic wave device having a single crystal aluminum nitride film wherein when the direction of propagation of the surface acoustic wave is expressed by (.lambda.,.mu.,.theta.) according to the Euler angle notation, .theta. is set to 90 degrees, .lambda. to a desired angle, and .theta. to an angle in the range of 30 to 150 degrees. In a surface acoustic wave device having a c-axis-oriented aluminum nitride film, the direction of c-axis orientation of the piezoelectric film is inclined within a plane containing the direction of propagation of the surface acoustic wave and perpendicular to the surface of the piezoelectric film at an angle in the range of about .+-.30 degrees to about .+-.150 degrees with respect to a normal to the piezoelectric film. The devices are 1.122% in maximum coupling coefficient.

Abstract: A touch control system for a cathode ray tube, or other touch-controlled device capable of recognizing touch positions along a predetermined coordinate axis on a three-dimensionally curved touch surface, includes a substrate comprising a segment of a three-dimensionally curved surface having a touch surface capable of propagating surface acoustic waves. An input surface wave transducer serves to launch a collimated beam of surface acoustic wave energy on the touch surface. If undisturbed, the beam would travel along a path that corresponds to a great circle on the curved surface. An output surface wave transducer develops an electrical output signal upon receipt of surface acoustic wave energy derived from the beam. A reflective array is provided which establishes travel of the beam of energy along a desired path on the touch surface having a contour intermediate a great circle and a parallel.

Abstract: A polymer piezoelectric film comprising a poled film of a vinylidene fluoride copolymer having a high molecular weight as defined by an inherent viscosity within a specific range comprising 40 to 90 mol. % of vinylidene fluoride and 10 to 60 mol. % of trifluoroethylene. Such a high molecular weight vinylidene fluoride copolymer can give a preferable state of molecular arrangement during film formation, particularly preferably formation by casting, to provide a film excellent in piezoelectric characteristic and secondary processing characteristic.

Abstract: A monolithic SAW convolver comprises a piezoelectric film, an insulator, a semiconductive epitaxial film and a high-concentrated semiconductive substrate. The semiconductive epitaxial film has a thickness in a predetermined range to improve the efficiency and the temperature property of the convolver.

Abstract: A surface acoustic wave device comprising a surface acoustic wave substrate member composed by forming an aluminum oxide film and a thin zinc oxide film successively on a glass substrate. The thickness h.sub.1 of the aluminum oxide film and the thickness h.sub.2 of the zinc oxide film are set within ranges of 0.1.ltoreq.h.sub.1 /.lambda..ltoreq.10 and 0.05.ltoreq.h.sub.2 /.lambda..ltoreq.0.35 (where .lambda. is representative of wavelength of Sezawa wave) respectively, thereby to utilize Sezawa wave or a similar mode wave transmitted on the surface acoustic wave substrate member in multi-layer structure.

Abstract: A surface acoustic wave resonator so constructed that multiple reflection of a surface acoustic wave in interdigital electrodes is suppressed, no sub-resonance caused by the multiple reflection occurs in the inductive areas, and the resonator effects a reliable excitation.

Abstract: A surface acoustic wave (SAW) diffraction-effect or interference-effect device with a highly isotropic substrate having a high coupling coefficient and low attenuation losses. The use of X-propagating rotated-Y-cut lithium niobate as the SAW substrate, with the Y rotation angle selected at 121 degrees, provides a practically isotropic material, with a high coupling coefficient and relatively low attenuation losses.

Abstract: Disclosed is a rotated Y-cut, quartz SAW device having a propagation direction gamma and an angular orientation theta selected both for stress compensation and temperature compensation. In a particular embodiment gamma is 46.9.degree. and theta is 41.8.degree..

Abstract: A surface acoustic wave device has been developed, such as a surface acoustic wave filter in which a plurality of electroacoustic interdigital electrodes are formed, as thin films made principally of aluminum, on the surface of a Li.sub.2 B.sub.4 O.sub.7 single crystal substrate and a surface acoustic wave resonator, in which a plurality of electroacoustic interdigital electrodes and grating reflectors for reflecting the surface acoustic wave are formed, as thin films made principally of aluminum, on the surface of a Li.sub.2 B.sub.4 O.sub.7 single crystal substrate. Here, a cut angle, at which the substrate is cut from the Li.sub.2 B.sub.4 O.sub.7 single crystal, and the propagation direction of the surface acoustic wave are so set that, when the Eulerian angle representation is (90.degree..+-..lambda., 90.degree..+-..mu., 90.degree..+-..theta.), .lambda.=38.degree. to 52.degree., .mu.=0.degree. to 5.degree. and .theta.=0.degree. to 10.degree., whereby the TCD of the surface acoustic wave device is below .

Abstract: A Quartz Crystal for surface acoustic wave device application defined by the Euler angles lambda (.lambda.) equal about 45.degree. and mu (.mu.) equal about 55.degree. with an acoustic wave propagation direction angle theta (.theta.) equal plus about 10.degree. to minus about 30.degree..

Abstract: An ST cut quartz crystal for surface acoustic wave device application defined by the Euler angles lambda (.lambda.) equal about 0.degree., mu (.mu.) equal about 132.75.degree. and with an acoustic wave propagation direction theta (.theta.) equal about plus or minus 25.degree..

Abstract: An electronic device, such as a Surface Wave, Bulk Wave or pyroelectric device, exploiting the polar nature of an active material in which the active material is lithium tetraborate or a closely related compound for example one which is slightly deficient in Lithium or Boron e.g. (Li.sub.2.-+..delta.1)B.sub.4 O.sub.7 or Li.sub.2 (B.sub.4.-+..delta.2)O.sub.7 where .delta..sub.1 and .delta..sub.2 are small numbers.

Abstract: In a video head position control apparatus utilizing a bimorph element (1), one or two surface acoustic wave oscillators (13, 15) is (are) formed by using piezoelectric element(s) (3, 4) of the bimorph element (1) for measuring displacement of a video head (5) attached to tip portion of the bimorph element (1) by detecting oscillating frequency variation. The oscillating frequency is used to detect an error of the position of the video head (5) with respect to a desired position indicated by a control voltage (V.sub.C1) which is fed from a video tape recorder such that peak voltage of the control voltage changes throughout different video tape velocity on various operating modes. The control voltage is thus corrected by an error voltage (V.sub.E) so that a corrected voltage is applied to the bimorph element (1) to cause the same to accurately position the video head (5).

Abstract: The 19.1 propagation X-cut of berlinite (AlPO.sub.4) has been discovered to have cubic temperature compensation for surface acoustic waves (SAW). The temperature variations of frequency or time delay over a 35.degree. to 85.degree. C. temperature range are comparable to ST-quartz. However, berlinite has at least twice the piezoelectric coupling. This is essential for low insertion loss, broadband SAW devices such as filters and correlators. In addition, 19.1 propagation, X-cut berlinite has lower volume wave spurious than ST-cut quartz.

Abstract: An X-cut, 33.44 degree quartz crystal for propagating surface acoustic waves with a temperature stability in the order of -0.0209 ppm/C.sup.2. The crystal orientation requires only a single rotation (33.44.degree.) from the crystal axes. This orientation is substantially simpler than previously reported cuts with comparable temperature stability which typically require three rotations. The X cut orientation has a surface acoustic wave (SAW) velocity of 3175 m/sec, an electromechanical coupling (.DELTA.v/v) of 4.times.10.sup.-4, and a power flow angle of 2.7 degrees.

Abstract: A surface acoustic wave device comprising a surface acoustic wave substrate member composed by forming an aluminum nitride film and a thin zinc oxide film successively on a glass substrate. The thickness h.sub.1 of the aluminum nitride film and the thickness h.sub.2 of the zinc oxide film are set within ranges of 0.1.ltoreq.h.sub.1 /.lambda..ltoreq.10 and 0.05.ltoreq.h.sub.2 /.lambda..ltoreq.0.3 (where .lambda. is representative of wavelength of Sezawa wave) respectively, thereby to utilize Sezawa wave or a similar mode wave transmitted on the surface acoustic wave substrate member in multi-layer structure.

Abstract: A surface acoustic wave device comprises a silicon substrate, an aluminum nitride layer provided on the silicon substrate, a zinc oxide layer provided on the aluminum nitride layer, and electrodes provided on either the silicon substrate, aluminum nitride layer or zinc oxide layer. Propagation is in the [001]- or [011]-axis direction on (100) Si, [001]- or [110]-axis on (110) Si, [112]-axis on (111) Si, or [111]-axis on (112) Si.

Abstract: A surface acoustic wave device comprises a silicon substrate, a silicon dioxide layer provided on the silicon substrate, a zinc oxide layer provided on the silicon dioxide layer and input and output electrodes provided on the zinc oxide layer. The silicon substrate is cut by a crystalline surface substantially equivalent to the (100)- or (110)-surface, and the zinc oxide layer is such that its crystalline surface substantially equivalent to the (0001)-surface is parallel to the cut-surface of the silicon substrate, so that a surface acoustic wave entered from the input electrode is propagated to the output electrode in a direction substantially equivalent to the [011]- or [001]-axis of the silicon substrate.

Abstract: A surface acoustic wave device comprises a silicon substrate, a conductive layer provided on the silicon substrate, a silicon dioxide layer provided on the conductive layer, input and output electrodes provided on the silicon dioxide layer for input and output of a surface acoustic wave, and a zinc oxide layer provided on the electrodes. The silicon substrate is cut by a crystalline surface substantially equivalent to the (111)-surface, and the zinc oxide layer is such that its crystalline surface substantially equivalent to the (0001)-surface is parallel to the cut-surface of the silicon substrate, so that the surface acoustic wave entered by the input electrode travels to the output electrode in a direction substantially equivalent to the [112]-axis of the silicon substrate.

Abstract: A high electromechanical-coupling surface acoustic wave device has a lithium niobate rotated Y-cut crystal as a piezoelectric substrate, and a thin high-density film formed on a predetermined portion of the lithium niobate rotated Y-cut crystal which includes at least a propagation path along which the surface acoustic wave propagates. A Love wave propagates in the thin or thick high-density film on the surface of the lithium niobate rotated Y-cut crystal substrate, so that the electromechanical coupling coefficient of the thin film can be improved, and spurious response caused by a Rayleigh wave can be eliminated.

Abstract: Disclosed is a polarized, shaped material comprising a copolymer of 40 to 87 mol % of vinylidene fluoride, 10 to 40 mol % of trifluoroethylene and 3 to 20 mol % of vinyl fluoride.

Abstract: An epitaxial structure in which a constraint imposed by forced epitaxy causes an increase in the piezoelectric effect of a group of layers. The structure which provides this effect utilizes a semi-insulating substrate made from a first material on which is deposited by forced epitaxy a layer of a second material, the two materials are in crystalline mesh parameter disharmony, which creates in said layer a constraint increasing its piezoelectricity. On the constrained layer are deposited two groups of alternated "deforming" and "deformed" layers of the two materials. The thickness of the structure is sufficient to allow propagation of the surface waves. The advantage of this structure is that it allows two transducers such as transistors to be integrated on or at the side of this structure.

Abstract: A piezoelectric wafer of single crystal berlinite, having a surface defined by an X-axis boule cut at an angle in the range from about 94.degree.-104.degree., provides an improved substrate for a surface acoustic wave device. These cut angles are relatively easy to fabricate, provide excellent temperature compensation in a range from -55.degree. C. to 125.degree. C., and have high piezoelectric coupling coefficient.

Abstract: An electronic device, such as a Surface Wave, Bulk Wave or pyroelectric device, exploiting the polar nature of an active material in which the active material is lithium tetraborate or a closely related compound for example one which is slightly deficient in Lithium or Boron e.g. Li.sub.2 .-+., S.sub.1 B.sub.4 O.sub.7 or Li.sub.2 B.sub.4 .-+.S.sub.2 O.sub.7 where S.sub.1 and S.sub.2 are small numbers.

Abstract: An acoustic surface wave device includes a substrate made of an elastic material, a multilayer structure disposed on a surface of the substrate and having a silicon dioxide layer and an aluminum nitride layer superimposed on each other, and electrodes having predetermined configurations formed on the multilayer structure. The main component of the elastic material is a silicon monocrystal, whose temperature coefficient of delay time for acoustic surface waves is positive, and the piezo-electric axis of the aluminum nitride is either perpendicular or parallel to the surface of the substrate, with a negative delay coefficient, counteracting that of the substrate.

Abstract: An acoustic surface wave device using an interdigital electrode array 2, 3 to launch and receive surface waves overcomes problems of diffraction by making the arrays approximately 3.lambda..sub.c wide between the outer boundaries of the bus bars. As a result, the arrays can each only propagate and transduce a single acoustic surface waveguide mode which is symmetrical about the axis of the array.

Abstract: A surface acoustic wave device comprises an elastic substrate having a major surface with a given crystal orientation and having a positive temperature coefficient of delay (TCD), and AlN film deposited on the elastic substrate so that piezoelectric axis of the AlN film has a predetermined direction with respect to the major surface of the elastic substrate having a negative TCD, and electrodes provided on the AlN film or between the elastic substrate and the AlN film.

Abstract: A piezoelectric wafer of single crystal berlinite, having a surface defined by an X-axis boule cut at about 85.degree., provides a improved substrate for a surface acoustic wave device. The 85.degree. cut angle is relatively easy to fabricate, provides excellent temperature compensation in a range form 20.degree. C. to 100.degree. C., and has high piezoelectric coupling coefficient.

Abstract: An acoustic surface wave device uses an in-line arrangement of two apodized interdigital electrode arrays 2, 3 to launch and receive surface waves to overcome problems of short overlap sources and of diffraction by making the arrays approximately 3.lambda..sub.c wide between the outer boundaries of the bus bars so that the arrays can each only propagate and transduce a single acoustic surface waveguide mode which is symmetrical about the axis of the array. Because the acoustic surface wave energy is propagated in a guided mode, energy launched by pairs of electrodes with a short overlap rapidly spreads to fill the entire transducer aperture and a similar situation in reverse applies at the receiver.

Abstract: A surface acoustic wave transducer has a multilayered substrate which is made of a nonpiezoelectric plate which has a surface which is coated with a piezoelectric film, and has an interdigital electrode which is disposed on or under the surface of the piezoelectric film. The interdigital electrode has a split structure and the phase velocity of the surface acoustic wave of the piezoelectric film is smaller than that of the nonpiezoelectric plate.

Abstract: A surface acoustic wave (SAW) device configured to operate as a spectrum analyzer, and having an array of input transducers disposed on a substrate in such positions as to produce a focused beam of acoustic energy at a focal arc, each position on the arc being representative of an input signal frequency. Output transducers produce electrical signals corresponding to the energy received at successive segments of the focal arc. The disclosed device includes various combinations of input transducer array improvements, some of which are to provide amplitude weighting of the input array, including aperture width weighting, capacitive weighting, resistive weighting, series-parallel weighting, and source withdrawal weighting. Another improvement in input array configuration eliminates close or overlapping electrodes of opposite polarities and thereby reduces parasitic capacitance and acoustic radiation between electrode elements.

Abstract: The inherent temperature instability of surface acoustic wave (SAW) clock oscillators is improved by the use of a thermometer oscillator circuit that senses temperature changes in the SAW substrate. The thermometer oscillator is used in combination with a calibrated programmable read only memory and a logic circuit and provides frequency corrections to the clock oscillator. The basic device is an oscillator clock circuit using a SAW substrate having a delay path orientation with good temperature stability. A second oscillator, the thermometer oscillator circuit, and the electronic compensation scheme are added in order to produce minimum temperature coefficient of delay over all temperatures in the range of interest. The thermometer oscillator delay path utilizes a high temperature coefficient of delay orientation of the same SAW substrate and at an appropriate angle to the clock oscillator delay path orientation.