Abstract: A quartz crystal resonator is utilized to effect evaluation of the viscoelastic characteristic of a film deposited on an electrode by an electrochemical reaction. The quartz crystal resonator is connected to a resonator characteristic measurement unit comprised of an oscillating circuit, a frequency counter, and an amplitude level meter. An electrochemical measurement unit in the form of a potentiostat is connected to a working electrode which comprises one of the electrodes of the resonator, to a reference electrode and to a counter electrode. The frequency counter, the amplitude level meter and the potentiostat are connected to a CPU. The resonator, reference electrode and counter electrode are all immersed in an electrolyte solution in an electrochemical cell.

Abstract: A surface acoustic wave device having a diamond layer, a piezoelectric layer and a comb-like electrode, in which the piezoelectric layer and the comb-like electrode are formed on a surface of the diamond layer, which surface has been contacted to a substrate used in the formation of the diamond layer by a vapor phase growth method, which device has high stability and can be produced economically.

Abstract: A sensor for chemical vapor detection using a surface acoustic wave (SAW) ray that provides a means for simultaneously detecting several chemical agents. The sensor has a piezoelectric substrate and a bidirectional surface acoustic wave transducer on the substrate. Also on the substrate are several pairs of identical acoustic sensing and reference channels each on opposite sides of the transducer in a mirror image fashion. Each channel pair has a thin film capable of absorbing a chemical vapor to be monitored and a metallic surface acoustic wave grating reflector capable of receiving and reflecting surface acoustic waves through the thin film and back to the transducer. An acoustic absorber separates each channel. The reference channels are protected from ambient conditions while the sensing channels are exposed to such conditions. An RF signal is applied to the transducer causing the propagation of an acoustic signal into each of the sensing channels and reference channels.

Abstract: A dual channel flexural device is fabricated on a gallium arsenide (GaAs) bstrate that includes a pair of elongated active vibrating (GaAs) bars formed in the substrate that serve as acoustic waveguides. One of the bars serves as a reference channel, while the other bar is covered with a chemically sensitive coating and operates as a sensing channel. A pair of pseudo-surface acoustic wave (SAW) transducers serving as input and output transducers are located at each end of the bars. Each of the transducers is comprised of discontinuous U-shaped elements having dimensions and mutual separations of one half the acoustic operating wavelength formed on one side of the substrate while ground electrodes are formed thereunder on the opposite side of the substrate. When the transducers are energized, a flexural motion in the bars is set up, causing the bars to vibrate.

Abstract: A controlled conductivity device utilizes incident phonons (1) to control conductivity. A body of material (2) is capable of changing its conductivity in response to the incident phonons by undergoing a metal-insulator transition.

Abstract: An assembly includes a Surface Acoustic Wave (SAW) component disposed within a housing or capsule by supports which support the component close to, but not in contact with, the bottom of the housing or capsule, thereby allowing some movement of at least portions of the component within the housing or capsule.

Abstract: A method of manufacturing a surface acoustic wave device which has a smaller insertion loss and which operates at higher frequency than a conventional surface acoustic wave device is provided. The surface acoustic wave device includes a substrate, a diamond layer formed on the substrate, a piezoelectric layer formed on the diamond layer, and electrodes formed on any of the substrate, the diamond layer and the piezoelectric layer. The piezoelectric layer is formed by the laser ablation method. The insertion loss of this acoustic wave device is small even in a high frequency range of several hundreds MHz to GHz. Therefore, the device can be used as a frequency filter, a resonator, a delay line, a convolver, a correlator and the like.

Abstract: A novel heterostructure acoustic charge transport (HACT) device is disclosed having an optimized charge density. The device includes a transducer fabricated on a substrate structure that launches surface acoustic waves. A reflector is formed in the substrate structure at an end portion adjacent to the transducer for reflecting the surface acoustic Waves. Also included is an electrode configured with the transport channel at an end thereof distal to the transducer for generating electrical signal equivalents of the propagating electrode charge. During fabrication, the resistivity of the layers initially configured at a lower than desired value. The layer is subsequently etched to raise the resistivity to the desired value.

Abstract: A novel heterostructure acoustic charge transport (HACT) device is disclosed which displays both electron and hole transport. The device includes a transducer fabricated on a substrate structure that launches surface acoustic waves. An optional reflector is formed in the substrate structure at an end portion adjacent to the transducer for reflecting the surface acoustic waves. Also included is an electrode configured with the transport channel at an end thereof distal to the transducer for generating electrical signal equivalents of the propagating electrode charge. The device makes use of both the conduction band quantum well to transport electrons and the valance band quantum well to transport holes. In this manner the sampling, processing and detection frequencies of the device can be doubled.

Abstract: A low loss microwave surface acoustic wave filter, comprising input (2, 3) and output (4, 5) transducers, acoustically associated with coupling transducers (6, 7).The relative positions of the transducers 2 to 7) and of their O reflectors are chosen, having regard to the weightings of the coupling transducers (6, 7) in order to obtain the desired transfer function for this filter.

Abstract: A surface wave transducer has measures for suppressing internal reflections on terminal fingers of a transducer having other transducer fingers, which are arranged interdigitally adjacent to the terminal fingers, which are arranged corresponding to a specified acoustic wavelength of the transducer at intervals specified by a predetermined scheme and which are designed with finger widths that are likewise specified by the predetermined scheme. On each end of the transducer only a plurality of terminal fingers, which are connected to one busbar of the transducer, are positioned deviating from the scheme for positionings and finger widths of the other transducer fingers and are positioned deviating in their finger strip width.

Abstract: A surface acoustic wave device comprises lithium tetraborate single crystal substrate to make use of surface acoustic waves with higher propagation velocities and smaller propagation losses, whereby frequencies to be signal-processed can be as high as above 1 GHz. The surface acoustic wave device comprises a metal film formed on a surface of a lithium tetraborate single crystal substrate, the metal film being for exciting, receiving, reflecting and/or propagating surface acoustic waves, the metal film being so formed that a cut angle of the substrate, and a propagation direction of the surface acoustic waves are in an Eulerian angle representation of (39.degree.-51.degree., 66.degree.-114.degree., -20.degree.-20.degree.) and directions equivalent thereto. In this propagation direction few Rayleigh waves exit, and only surface acoustic waves of high propagation velocity are generated. Propagation losses can be eliminated.

Abstract: A surface acoustic wave device comprises a pair of multiple-electrode surface acoustic wave elements that are mirror-symmetrically arranged and disposed on a piezoelectric substrate. Each of the multiple-electrode surface acoustic wave elements comprises a plurality of input/output inter-digital transducers and connected inter-digital transducers. The number of the input/output inter-digital transducers is equal to or smaller by one, than the number of the connected inter-digital transducers, so that insertion loss of the surface acoustic wave device can be reduced without increasing the size of the device.

Abstract: An acoustic wave filtering apparatus includes an acoustic wave propagating substrate for supporting propagation of acoustic waves and a plurality of acoustic wave filters for filtering an electrical signal. Each of said plurality further comprises an input for supplying electrical input signals, an input unidirectional acoustic wave transducer for converting electrical signal energy into acoustic energy, an output unidirectional acoustic wave transducer for converting acoustic signals to electrical signals, and an output for combining and delivering electrical output signals to external electrical apparatus.

Abstract: A SAW detector has a SAW transducer 10 disposed on the surface of a piezoelectric substrate 12 which injects a SAW 20 in response to an RF input signal applied to line 14. A semiconductor charge transport region 30 comprising a charge transport channel 32 sandwiched between two charge confinement layers 34,36, is disposed above the substrate. A source electrode 40 provides electrons to the channel 32 and a drain electrode 42 removes electrons from the channel 32. The electric fields generated by the SAW 20 travel along the channel 32 and provide a forcing function to move the electrons from the source electrode to the drain electrode as a continuum, not in charge packets, thereby providing output current 48 on a line 49 indicative of the SAW 20 frequency.

Abstract: An inductive element for impedance matching comprises an acoustic wave propagating substrate and an acoustic wave transducer coupled to the acoustic wave propagating substrate. The acoustic wave transducer has an effective length L.sub.eff such that Le.sub.eff .gtoreq.C.sub.2 v.sub.a /f.sub.o k.sup.2, where C.sub.2 is a numerical factor such that C.sub.2 .gtoreq.2, v.sub.a represents an acoustic velocity, f.sub.o represents an acoustic wave transducer center frequency and k.sup.2 denotes an acoustic wave propagating substrate electromechanical coupling coefficient. Reflecting elements are provided on the substrate in the principal acoustic propagation directions to form a resonant acoustic cavity. The device exhibits inductive impedance and high Q over a significant frequency range in small physical size.

Abstract: A surface acoustic wave device in which a surface acoustic wave device element is arranged with interdigital electrodes on a piezoelectric substrate is packaged in a package provided in a metal pattern. Metal bumps are formed on a bonding pad section of the surface wave device element and the metal bumps are contact connected with the metal pattern of the package.

Abstract: In a radio transceiver (100), an IF stage (110) is formed on a single substrate. A balanced or image rejection mixer (204) having two pairs of inputs and a pair of outputs is integrated on an IC substrate (202). Disposed on the IC substrate are SAW transformers (210, 212 and 214) which provide a desired phase transformation. The SAW transformers comprise piezoelectric layers (228) and metallization layers (230) which are suitably patterned to provide the desired phase transformation and frequency selectivity.

Abstract: A HACT device which propagates charge packets 21 along a charge transport channel 17 by a surface acoustic wave (SAW) 14 is provided with an interdigital electrode grid 30 disposed on the upper surface of the HACT, near the charge transport channel 17, having electrodes 30 spaced a distance of one-half wavelength of the SAW. A hold voltage Vh is applied across alternating electrodes to store (i.e., stop and hold) each charge packet. When a charge packet is to be released, the hold voltage Vh is removed and the electrodes 30 are shorted together or alternatively connected through a maximum allowable impedance, thereby allowing each charge packet 21 to be stored and released by the device without having the electrodes 30 absorb the SAW electric fields. Because the electrodes 30 are spaced one-half a SAW wavelength apart, the HACT memory can store each and every charge packet 21, thereby providing a Nyquist bandwidth device.

Abstract: A convolver has a piezoelectric film layer, an insulator layer and a semi-conductor layer. A surface resistance measurement part permits measurement of a surface resistance related to the surface resistance seen by a gate electrode of the convolver. The surface resistance part is changeable by a bias voltage applied to the convolver. The amplitude of the bias voltage is controlled to set the surface resistance at a value which produces a desired convolution efficiency of the convolver. The convolver is adaptable to be fabricated as an integrated circuit with a simple structure. A transmitter/receiver system is disclosed in which a transmitted SSC signal is modulated by a pseudo-noise (PN) signal, as well as by a normal modulation. In the receiver, the PN component of the signal is removed using a convolver according to the present invention, to correlate the received signal before detection thereof.

Abstract: A surface acoustic wave device which is a surface acoustic wave resonator utilizing an SH-type surface wave, wherein a resin layer made of a resin material in the form of gel or having a Shore hardness of not more than 30 is formed so as to coat at least an interdigital transducer formed on the upper surface of a piezoelectric substrate.

Abstract: A surface acoustic wave element has a low insertion loss in one direction and a wide band width. This surface acoustic wave element has first and second interdigital electrodes each having a thickness on a piezoelectric or electrostrictive substrate. In a first interdigital electrode for exciting a surface acoustic wave, positive and negative electrodes are alternately arranged such that their electrode widths and periods are gradually decreased in a direction of propagation of the surface acoustic wave. In a second interdigital electrode for receiving the surface acoustic wave, positive and negative electrodes are alternately arranged such that their electrode widths and periods are gradually increased or decreased in the direction of propagation of the surface acoustic wave.

Abstract: A surface acoustic wave device and its manufacturing method. A surface acoustic wave device is used as filters for VHF and UHF range signals, or resonators for VHF and UHF range, by driving the surface of a surface acoustic wave element with applied signal to electrodes, transmitting a surface acoustic wave, and receiving the surface acoustic wave with other electrodes. In a configuration of a surface mount type surface acoustic wave device where a surface acoustic wave element is stored inside a package consisting of a base and a cover, pads are attached on a surface of the base and the surface acoustic wave element is fixed to the base by face down bonding.

Abstract: A high speed analog to digital converter system employs a set of ACT devices in parallel to buffer a high speed data sampling rate to the processing rate of the analog to digital converters employed. Vernier control of phase between individual devices is maintained by controlling the speed of propagation of the SAW wave by illumination of the substrate in response to a phase comparison between the SAW and a reference signal.

Abstract: In an SAW convolver device constructed by sealing an SAW convolver element having a piezoelectric film/insulator/semiconductor structure by means of a cover of a package, according to the present invention, an insulating base plate is disposed on a part of a metallic base plate of the package, on which insulating base plate there is disposed a resistor or a coil, and the gate electrode of the convolver is grounded in a DC-like manner through the resistor or coil.Owing to the construction described above, it is possible to prevent that a voltage due to electrostatic charge, an accidental voltage due to erroneous handling, etc. are applied to the gate electrode of a zero bias type SAW convolver. As the result, it is possible to stabilize characteristics of the zero bias type SAW convolver for a long period of time and to improve the reliability thereof.

Abstract: Disclosed is a coplanar waveguide (CPW) which is connected directly into a balanced SAW transducer" via a tapered coplanar transmission line. Preferably, the CPW transition feeds directly into the "balanced transducer" such that the ground planes of the CPW taper directly into the outer (grounded) bus bars of the SAW transducer and the center conductor of the CPW feeds directly into the "hot" center electrode structure of the SAW transducer. This preferred structure is shown in FIG. 1. This balanced SAW transducer configuration provides better electrical shielding for lower electromagnetic feedthrough suppression and lower spurious signal levels. Moreover, the acoustic wave generated by this "balanced transducer" configuration provides a more uniform acoustic power distribution because the center conductor of the SAW transducer provides a waveguide effect wherein the acoustic energy tends to follow the slow velocity metal structure, thus forming an acoustic waveguide.

Abstract: A surface acoustic wave (SAW) device package for reducing insertion loss and direct RF feedthrough of the SAW device is disclosed. The package provides for extensive shielding of each of the input and output pads. The inputs and outputs to the SAW device are separated by maintaining the inputs on one surface of the substrate and the outputs on the opposite surface of the substrate. The SAW crystal substrate including the SAW devices is bonded to the package substrate and the package is hermetically sealed via a low-temperature glass seal or solder-type sealing, for example.

Abstract: Disclosed herein is a surface acoustic wave device whose characteristics can be stably maintained against temperature changes. The surface acoustic wave device has an insulating diamond layer (2), which is provided thereon with a part (3) defined by a pair of interdigital electrodes (7, 7') and a piezoelectric layer (8), and a thermistor (4) made of semi-conductive diamond. The thermistor (4) quickly detects the temperature of the device.

Abstract: IDT electrodes (4) are provided in a two-layer structure of a diamond crystal (2) in an AlN thin film (3) so that a third Rayleigh wave or a Sezawa wave propagates in the two-layer structure. Or else, a third Rayleigh wave propagates in a substrate of a three-layer structure wherein a SiO.sub.2 film is provided between a diamond crystal (2) or an AlN thin film (3). SAW devices which have high electromechanical coupling coefficients and high phase velocities are obtained based on those structures. A SAW device in which a third Rayleigh wave propagates is suitable for a narrowband timing tank filter or bandpass filter which is used in a microwave region of several GHz to 20 GHz. A SAW device in which a Sezawa wave propagates is suitable for a wideband voltage-controlled oscillator or a wide bandpass filter which is used in a wide frequency range from the VHF-band to the UHF-band.

Abstract: Surface acoustic wave devices making use of the interaction between surface acoustic wave and carriers include at least a semiconductor part, a piezoelectric layer and an intermediate insulating film. The devices of this invention include diamond or diamond-like carbon as the insulating film in contact with the piezoelectric layer. Since diamond or diamond-like carbon has the highest sound velocity, the surface acoustic wave velocity is extremely high in the piezoelectric layer in contact with diamond or diamond-like carbon. The high surface acoustic wave velocity alleviates the need of producing fine inter digital transducers. This invention is applicable to surface acoustic wave phase-shifters, surface acoustic amplifiers and surface acoustic convolvers.

Abstract: A high-sensitivity surface wave gas sensor in which the interaction of a surface wave field with a solid film suitable for adsorbing the gas to be determined causes a change in the frequency of an oscillating circuit containing a surface wave delay line as a function of the type and concentration of the gas entails the delay line provided for adsorption of the gas being completely coated with the solid film, and the dimensions of the delay lines being such that the length of the surface wave transformer is greater than that of the delay line.

Abstract: An SAW (surface acoustic wave) device is disclosed, in which a plurality of SAW delay lines and a plurality of SAW convolver elements are combined; signals delayed by predetermined amounts by the combined SAW delay lines are used as input signals to the SAW convolver elements; and output signals thus obtained from the plurality of SAW convolver elements are added together to be taken out so that apparently a processing time, which is equal to a signal processing time of a single SAW convolver element multiplied by an integer, can be obtained.

Abstract: A passivation layer of dielectric material disposed on the top surface of the SAW device prevents the metallized transducer pattern on the piezoelectric substrate from being exposed to chemical attack. This layer also provides for improved metal acousto-migration resistance through the well-known mechanism of grain boundary pinning. The piezoelectric SAW device substrate includes a dielectric layer which is disposed along the surface over the transducer metallization. The piezoelectric substrate includes metallized regions on top of the dielectric layer which is disposed over the substrate surface and the SAW transducers thereon. These metallized regions form capacitors to the transducer busses and capacitively couple electrical input and output signals to the transducers from external electronic apparatus.

Abstract: A fluid sensing device such as a Shear Transverse Wave device or a Love Wave device having a wave-trapping structure that provides tight surface trapping at transduction and sensing regions, but permitting a deeper penetration of wave energy at the interface of a seal with the wave-trapping structure. In the STW device, wave-trapping fingers are selectively varied in thickness, width or both to achieve the selective trapping. In an LW device, a wave-trapping plate is reduced in thickness at seal regions.

Abstract: A novel surface acoustic wave (SAW) element for use in a stabilized oscillator circuit capable of coupling directly to external circuitry includes a pair of opposed transducers formed on a surface of a piezoelectric crystal for launching surface acoustic waves into a resonant cavity formed by opposed reflectors on the crystal surface. The element is characterized by a supplemental transducer coupled to the cavity for directly providing external circuitry with signals corresponding to the resonant surface acoustic waves.

Abstract: A SAW oscillator package having low vibration sensitivity includes a stiffener layer disposed between a mounting surface for the oscillator and the oscillator circuit package. Preferably, the stiffening layer comprises a slab of a highly stiff material such as a ceramic and, in particular, aluminum oxide, as well as other material which preferably have suitable thermal expansion coefficients matched between the material of the package and the mounting surface. Moreover, the rigidly of the SAW device itself is also increased by either reducing the lateral dimensions of the SAW device or increasing the thickness of the SAW substrate and/or cover.

Abstract: A surface acoustic wave device is disclosed for use in a communication apparatus where the surface acoustic wave device has a multiple of surface acoustic wave elements with different filter characteristics formed on mutually distinct piezoelectric substrates. The different filter characteristics combine to form filters having desired filter characteristics.

Abstract: In a surface acoustic wave device for removing narrow band signals, detection sensitivity is significantly improved by disposing a group of metal strip arrays on the side opposite to output transducers with respect to input transducers on the surface of a piezo-electric film and connecting a group of diode arrays with this group of metal strip arrays.

Abstract: A narrow band interference signal removing device uses first diode arrays and second diode arrays both provided in propagation paths of surface acoustic waves in order for the first diode arrays to detect the signal magnitude of a surface acoustic wave propagating in an opposite direction to obtain information on the spectrum magnitude of an input signal and responsively control a bias to the second diode arrays.

Abstract: A tapped delay line uses a varistor network for tap weighting. The varistors may be used in a resistive summing network or as amplifier gain control elements. In addition, the varistors can be programmed by a voltage programming circuit comprising a switch array, an input voltage programming bus, and sets of master and slave digital programming signals.

Abstract: A control apparatus for a surface acoustic wave convolver element having a gate electrode, a grounded electrode and a piezoelectric layer therebetween. A bias voltage variable within a predetermined range is applied to the gate electrode so as to cause the convolver element to operate at the optimum convolution efficiency. A first mode signal is output when the variable bias voltage is in the proximity of either end of the predetermined range, and a second mode signal is output when the variable bias voltage is in a range defined by excluding the first range from the predetermined range. The variable bias voltage is applied to the convolver element when the second mode signal is output. When the first mode signal is output, the characteristics of the convolver element are controlled at an increased rate relative to a control rate when said variable bias voltage is used.

Abstract: A surface acoustic wave (SAW) chirp signal processor having a piezoelectric substrate, an array of input transducers and an array of output transducers. In its chirp compression mode, the device has chirp signals applied in parallel to its input transducers and produces compressed output pulses at its output transducers, corresponding to selected chirp rates. The input transducers are successively offset with respect to a focal point on the array of output transducers, by distances that successively and linearly increase or decrease from transducer to transducer, consistent with the increase or decrease in the wavelength of the chirp signals. The device may also be used in a pulse expansion mode, by inputting a broadband pulse into a selected one of the output transducers. The input transducers then produce a chirp signal having a rate corresponding the selected to output transducer.

Abstract: In a nozzleless ink jet printer, a plate-shaped propagation element for propagating a surface acoustic wave is fixedly mounted on a substrate which is arranged along the platen and has an ink pooling groove, and the ink led to the edge of the propagation element from the ink pooling groove by surface tension is caused to jet in the form of ink mist by surface acoustic waves generated by excitation of comb-shaped interleaved electrodes so as to record images such as characters and patterns on a recording sheet.

Abstract: A surface acoustic wave apparatus wherein a reflector for reflecting a surface acoustic wave is provided on both sides of at least one of an input interdigital transducer and an output interdigital transducer, or, on one side of one of the input interdigital transducer and the output interdigital transducer.

Abstract: An acoustic delay line includes electrodes on a monolithic piezoceramic substrate, which serve as electro-acoustic transducers for the delay line. The distance between said transducers defines the transit time, and thus the delay path. Each transducer may have electrodes on the same side of the substrate, in which case thickness of the substrate is less than or equal to one-half the wavelength of the highest frequency to be transmitted in the substrate, so as to prevent the formation of higher modes. Alternatively, each transducer may have congruent electrodes on opposite sides of the substrate, in which case the thickness of the substrate is less than or equal to the wavelength of the highest frequency to be transmitted. The substrate is polarized substantially parallel to the equipotential lines which arise in the substrate upon the application of a voltage to the electrodes.

Abstract: A surface acoustic wave filter device having a surface acoustic wave filter chip disposed on the upper surface of a substrate, input and output conductor patterns provided on each of the upper and lower surfaces of the substrate, and grounding conductor patterns provided on each of the upper and lower surfaces of the substrate so as to surround the input and output conductor patterns on that surface in order to prevent an electromagnetic coupling between the input and output conductor patterns, whereby the out-of-band rejection of at least 40 dB is obtained in an operating band of at least 400 MHz.

Abstract: Interdigital transducers (3, 4) and reflectors (5, 6) are formed on a piezoelectric substrate (2) by an aluminum film. The aluminum film is crystallographically oriented in a constant direction, whereby stressmigration of the aluminum film is suppressed.

Abstract: An acoustic transducer for an acoustic wave device which includes an acoustic wave propagating substrate, the transducer adapted to couple to an electrical load and/or source. The transducer includes at least a pair of comb electrodes formed on the substrate. It includes apparatus for applying an electrical load and/or source across the pair of comb electrodes. The first of the combs has a plurality of electrode fingers. The second comb has at least one electrode finger. The widths of the electrode fingers are the same. Gaps of at least two different widths are disposed between the electrodes.

Abstract: A heterostructure acoustic charge transport (HACT) device having a number of signal tap electrodes has revealed unexpected insensitivity to electrode spacing and unexpected sensitivity to electrode width. Spacing of one SAW wavelength between consecutive electrodes and an electrode width of .lambda./20 are preferred.

Abstract: Interdigital transducers and reflectors are formed on a piezoelectric substrate from an aluminum film. The aluminum film is formed by electron beam deposition at a film forming rate which is controlled to be at least 20 .ANG. per second. The aluminum film formed in this way is crystallographically oriented in a constant direction, whereby stressmigration of the aluminum film is suppressed.