Abstract: An amplitude modulation apparatus for achieving an extremely deep extinction ratio (in excess of -90 dBc) at nanosecond rise times required by an SAW device comprises the cascaded combination of a controlled switching device (GaAsFET), capable of providing a medium degree (40 dB) of attenuation at nanosecond switching rates, and a double balanced mixer, both multiplier input ports of which are coupled to receive split outputs from the GaAsFET switch. Because of the nonlinearity of the transfer function of the mixer when driven by the same RF carrier input at both multiplier ports, the output of the mixer is in excess of -90 dBc. In an SAW-based signal processing system, the output of the mixer is coupled to RF drive input of the SAW device.

Abstract: In a surface acoustic wave elastic convolver capable of showing sufficiently high convolution efficiency with a simple structure, the convolver comprises a piezo-electric substrate, plural input transducers formed on the substrate for respectively generating surface acoustic waves corresponding to input signals, an output transducer for obtaining a convolution signal of the input signals, from a surface acoustic wave generated by non-linear interaction, of the surface acoustic waves generated by those input transducers, and a dielectric film of a non-linear effect larger than that of the substrate, formed on the substrate in at least an area where the output transducer is formed.

Abstract: The disclosure relates to a microstrip circuit which is used to combine the energy output from the convolving plate of a surface acoustic wave (SAW) monolithic elastic convolver. The convolving plate is tapped at its two ends and a Wilkinson combiner is used to sum the signals that propagate to the ends of the plate. The Wilkinson combiner is a three-port device with the two arms that couple to the convolver plate having their characteristic impedances set to match that of the acoustic waveguide. In view of the impedance match, no electromagnetic reflections are produced at the end of the convolving plate and all of the energy incident on the Wilkinson combiner is summed and delivered to the output port of the combiner. Additionally, the microstrip circuit has an impedance transformer to transform down to an impedance suitable for driving an output amplifier chain of a receiving system.

Abstract: A clock regeneration circuit which is formed as an integrated circuit except for a SAW (surface acoustic wave) filter module which can be used unaltered for a number of regeneration circuits which are provided for various clock frequencies and the design of the SAW filter modules for such regeneration circuits are designed such that the SAW filter modules have an increasing phase for decreasing clock frequency. An in-phase data rate generation is possible even though the integrated circuit always supplies the filter module with pulses of identical lengths for all clock frequencies and an improved clock regeneration circuit results.

Abstract: An optimum bias circuit for a convolver according to this invention searches automatically a bias voltage, which makes the convolution efficiency of a surface acoustic wave convolver highest and applies it to the gate electrode of the convolver.

Abstract: A delay line with multiple taps is provided in which a hyperbolically tapered input transducer directs a wave to a plurality of hyperbolically tapered partial reflectors. A plurality of hyperbolically tapered output transducer taps are aligned with each of the partial reflectors so that varying delays may be obtained over a wide frequency band.

Abstract: A unit comprising a printed board on which a plurality of surface acoustic wave (SAW) devices are installed. Each SAW device comprises a piezoelectric substate on which arrays of strip electrodes are formed. A cover is mounted over the SAW devices to hermetically seal the surfaces of the SAW devices on which the electrodes are formed. The terminals of the board are directly coupled to the terminals of the SAW devices.

Abstract: A surface acoustic wave device comprising a device body and a multilayer printed board. The body has a piezoelectric substrate on which arrays of strip electrodes are formed. The body is covered with an insulating film except for locations where terminals are formed. The printed board is spaced a given distance from the body. The terminals of the printed board are connected via a solder layer with the terminals of the device body.

Abstract: A surface acoustic wave device sealing method prepares a cavity-defining member and lead members for electrical connection. A surface acoustic wave element having a wave propagation surface and electrodes is bonded to the cavity member by an adhesive applied to the circumferential edge of the cavity so that the propagation surface is opposed to the interior of the cavity, and the electrodes are exposed to the exterior of the cavity member. The electrodes are connected to the lead members, and the resulting unitary body is sealed by a mass of resin.

Abstract: A surface acoustic wave device includes a semiconductor substrate, a piezoelectric film disposed on the semiconductor substrate, at least one pair of comb-shaped electrodes constituting an input transducer, and an output transducer a plurality of surface acoustic wave filters having different bands, which include a plurality of metal electrodes, so disposed that each of them is located between the input and output comb-shaped electrodes of each of the surface acoustic wave filters, a bias voltage applying arrangement for applying bias voltages to each of the metal electrodes; and a bias voltage regulating arrangement for regulating the bias voltages.

Abstract: A convolver having at least a first interdigital transducer for generating a first surface acoustic wave in response to an input signal and a second interdigital transducer for generating a second surface acoustic wave counter to the first surface acoustic wave in response to a time reversed-time multiplexed reference signal. A segmented summing bus having a plurality of fingers extending into the interaction region of the first and second surface acoustic waves generates a plurality of samples indicative of the convolution of the first and second surface acoustic waves. The convolver also includes a pair of acoustic horns, one disposed between the segmented summing bus and each of the interdigital transducers and a ground bus having a plurality of filler segments extending intermediate the fingers of the segmented summing bus.

Abstract: Self-scanned piezoelectric delay line effective for time multiplexing system sampled physical parameters, subject to frequency mixing of the product signals from a clocked RF signal generator passing through a plurality of electrodes in the delay line, and the signals of voltage controlled oscillators driven by sensor detectors linked to the physical system.

Abstract: A large bandwidth, tapped delay line (TDL) surface acoustic wave (SAW) adaptive processor arrangement, for processing a plurality of array values employed as tap weights in the TDL device. The weight quantities may be real or complex. In the complex case, no phase quadrature combiner is required as a result of the technique of offsetting the real and imaginary delay lines, or offset launching of the frequency waveforms to be mixed.

Abstract: A large bandwidth, tapped delay line (TDL) surface acoustic wave (SAW) adaptive processor arrangement, for processing a plurality of array values employed as tap weights in the TDL device. The weight quantities may be real or complex. In the complex case, no phase quadrature combiner is required as a result of the technique of offsetting the real and imaginary delay lines, or offset launching of the frequency waveforms to be mixed.

Abstract: The invention of this disclosure comprises a system that simultaneously determines the frequency and direction of arrival of incoming signals. The apparatus of this invention comprises a layered half space dispersive delay line which is utilized as a beam forming element in a device that performs a two-dimensional Fourier transform on a function which is both time and space dependent.A pulse appears at the end of the delay line at a time which corresponds to the frequency of the incoming signal and the position of the pulse along the edge of the delay line is related to the direction of arrival of the incoming signals.

Abstract: A chirp signal generator circuit includes a pulse generator PG for generating a single impulse for application to first surface acoustic wave device SAW. This device produces an output signal comprising several cycles of energy at a predetermined frequency. A threshold circuit TH passes only that part of the output signal which second surface acoustic wave device EXP having the predetermined frequency as its center frequency, and this output signal is then amplified. The second device EXP generates a frequency modulated chirp signal.

Abstract: The surface acoustic wave device comprises an elastic substrate, a piezoelectric film deposited on the elastic substrate, and transducers and matching circuits both provided on the piezoelectric film or along the interface between the piezoelectric film and the elastic substrate.

Abstract: A thick film device conductor arrangement suitable for making connections between a resiliently mounted element such as a surface acoustic delay line and adjacent thick film conductors and then with the device connecting pins. The thick film conductors include a double layer structure of differing noble metals each selected for desirable properties in designated areas of the device.

Abstract: A surface acoustic wave apparatus comprises a surface acoustic wave element having one input electrode to which an input signal is supplied and two output electrodes, a variable gain element connected to the one output electrode, and an adder for adding the output of the variable gain element and the output of the other output electrode. The phase characteristic and the delay time characteristic of a filter determined by the input electrode and the one output electrode are the same as those of a filter determined by the input electrode and the other output electrode, respectively. Therefore, even if the amplitude-frequency characteristic of the adder varies, the phase characteristics and delay time are kept constant.

Abstract: A surface acoustic wave (SAW) filter partially coated with an acoustical wax, such as one soluble in trichlorethylene, or with an epoxy paint dramatically improves the performance of the filter, especially with regard to the attenuation of out-of-band signals.The coating pattern may be initially empirically determined depending on the substrate and transducer configuration but once determined is readily amenable to known printing and stamping techniques.

Abstract: An analog adaptive filter for deconvolving distorted signals. A clipped vion of the least mean square algorithm is implemented in a first embodiment by placing an acoustic surface wave storage correlator in a feedback loop and performing an iterative two step process to adjust the weight function of the correlator to make the output of the filter converge to a desired signal. In the first step, the distorted signal is applied to the top plate port of the storage correlator and the filter output from the acoustic port is delayed and subtracted from a training signal to produce an error signal. In the second step, the error signal is applied to the top plate port and the distorted signal is applied to the acoustic port which results in the correlation of the acoustic signal and the plate signal being added to the weight function stored in the storage correlator. The two step process is repeated until the filter output from the plate port converges to an approximation of the training signal.

Abstract: A surface elastic wave element comprising a (110)-oriented silicon substrate, a zinc oxide layer formed on the silicon substrate and electrodes formed on the zinc oxide layer so as to propagate surface elastic wave to the [001]-axis direction of the zinc oxide layer.

Abstract: A broad band surface acoustic wave (SAW) device has an edge-deposited transducer (EDT) capable of frequencies in excess of 1 GHz and bandwidths in the hundreds of MHz. The device includes a transducer on a semiconductor substrate which is either non-piezoelectric or weakly piezoelectric. The substrate has a sharp, smooth edge formed by the intersection of its top and a side surface. The transducer includes a passivation layer deposited on the side surface of the substrate and a starter layer deposited on the passivation layer; an inner metallic (gold, for example) electrode deposited on the starter layer; a transducer layer deposited on the inner metallic electrode; and an outer metallic electrode deposited on the transducer layer. The outer electrode is formed on the transducer layer one-fifth wavelength below the top surface of the substrate.

Abstract: A surface acoustic wave convolver (10) with parabolic horns (16, 18), a typical horn (16) having a compensating stub (16a) at the horn input end (16b) disposed centrally on the horn longitudinal axis (19) to maintain the phase coherence at the horn output end Z(16c) of a wave traversing said horn (16).

Abstract: The use of fabricated periodic piezoelectric structures fabricated from h resistivity semiconducting crystals in detecting millimeter waves in the GHz range is disclosed.

Abstract: An acousto-optic time integrating two-dimensional frequency scanning correlator for cross-correlating signals which are separated in frequency. Two coherent light beams which are derived from the same laser are fed across respective Bragg cells, one cell having the signal A(t) cos .omega..sub.A t propagating thereacross and the other cell having the signal B(t) cos .omega..sub.B t propagating thereacross. The respective output beams are comprised in the x direction and expanded in the y direction and are made incident on an acousto-optical correlator device having chirp signals counter-propagating thereacross. The optical output is fed to a time-integrating photodiode array which provides an output signal corresponding to the cross-correlation of A(t) and B(t). In a further embodiment, the two Bragg cells are replaced by a single Bragg cell and beams having different polarizations are fed thereacross.

Abstract: For quantitative potential measurement of surface-wave filters, an alternating voltage with amplitude U.sub.E.sbsb.i is connected to an input transducer of the surface-wave filter. At a local region for measurement on the filter, an alternating voltage of amplitude U.sub.P arises. For each such measuring location, the voltage U.sub.P is compared to a nominal value and if it deviates therefrom, this deviation is utilized to control an amplitude of the input voltage U.sub.E.sbsb.i so as to maintain the voltage U.sub.P substantially constant. For the various measurement locations, the changes of the input voltage U.sub.E.sbsb.i are analyzed and a local attenuation factor for each measured region in the filter may be determined. By knowing a frequency of the driving alternating voltage, conclusions can be drawn concerning specific characteristics of the filter.

Abstract: A surface acoustic wave device wherein a laminated structure comprised of a piezoelectric member and a metal electrode or electrodes is provided on a surface acoustic wave surface of an elastic body and an acoustic impedance discontinuous face is formed on the elastic body, so that a longitudinal wave generated by the laminated structure is reflected by the acoustic impedance discontinuous face to provide a transverse wave.

Abstract: An interdigital surface acoustic wave transducer comprises a substrate having at least two areas. One area has piezoelectric properties. Laid down on it is a main row with electrodes. The other area has no piezoelectric properties and carries an additional row with electrodes. Each row comprises two groups of electrodes arranged in parallel with one another. The electrodes of first groups of the rows are connected electrically to respective current-conducting pads. The electrodes of second groups of the rows are connected conductively to one another and are positioned between the electrodes of the first groups of the rows. As a result, overlap portions of the electrodes of the two groups are formed which have a constant length in the main row and a variable length in the additional row.

Abstract: A convolver based on the propagation of acoustic waves at the surface of a piezoelectric solid comprises a piezoelectric substrate, means for exciting two backward-traveling acoustic waves at the frequency f, means consisting of at least two electrodes for collecting the signal at the frequency 2f, the signal being produced as a result of nonlinear interaction of the two acoustic waves. The convolver device is connected to one of the two electrodes by means of a plurality of electrical contacts placed lengthwise and at intervals along the axis of propagation of the two interacting acoustic waves which are representative of the electrical signals applied to the two convolver inputs.

Abstract: An acoustic surface wave device is disclosed for generating an output signal that is the phase-conjugate of the input signal to the device. Disposed on the piezoelectric substrate is a first interdigital transducer for receiving a modulated input signal having a carrier center frequency f.sub.1 and for converting the input signal to an input acoustic wave. A semiconductor material is disposed over the surface of the piezoelectric substrate. A second interdigital transducer is disposed on the surface of the piezoelectric substrate between the first interdigital transducer and the semiconductor material. A standing wave at frequency f.sub.1 is generated by counterpropagating pump waves in the nonlinear acoustic wave interaction region in the area of the semiconductor material.

Abstract: A method for trimming the resonant frequency of fabricated SAW devices. The resonant frequency of SAW devices of the type having a substrate with structures made of a second material, other than the substrate material, upon its surface, is decreased by removing quantities of the substrate material until the desired change in frequency is obtained. In one embodiment, the substrate material of the SAW device is removed by etching the substrate in a fluorocarbon plasma, which leaves the structure made of the second material substantially unchanged. In a second embodiment, the resonant frequency of SAW resonators is increased by heating the SAW device at a temperature in excess of 250.degree. C. until the desired change in resonant frequency is obtained.

Abstract: A surface acoustic wave variable time delay includes a surface acoustic wave device (10) which is secured within a housing (30). The device (10) is provided with an input transducer (12) and an output transducer (16) which are respectfully connected to input lines (14) and output lines (18). An electrostrictive element (20) is secured within housing (30) between an end of device (10) and an interior wall (34) of housing (30). A control signal is applied to electrodes (22, 24) connected to element (20) to vary the size thereof. Element (20) applies a mechanical force to the surface acoustic wave device (10) to alter the distance between the input transducer (12) and output transducer (16) to thereby control the delay time between the signal supplied to the input lines (14) and the output signal at the output lines (18).

Abstract: A continuously variable delay line (10) includes a piezoelectric crystal (12) having an input transducer (14) and an output transducer (16). An input signal is transmitted through input lines (18) to the input transducer (14) and received through output lines (20) from the output transducer (16). The input signal is converted to a surface acoustic wave for transmission across the surface of crystal (12). Control electrodes (22 and 24) are applied to surfaces of the crystal (12) and are connected to control lines (26). A control signal is applied to the control lines (26) to apply an electric field to the crystal (12). The electric field thus applied alters the longitudinal dimensional characteristic of the crystal (12) and thereby controls the propagation distance between the input transducer (14) and the output transducer (16).

Abstract: A surface acoustic wave device is provided which includes a phase-modulated interdigital electrode and a uniform interdigital electrode having an equal electrode finger width and spacing, and the device is arranged to avoid occurrence of deviation of the actual performance thereof from the designed one. To this end, the electrode finger width and spacing of the uniform interdigital electrode are determined such that the ratio of metal surface to unmetallized substrate area in the phase-modulated interdigital electrode becomes equal to the ratio of metal surface to unmetallized substrate area in the uniform inter-digital electrode.

Abstract: A sensor formed on the surface of a body of piezoelectric material. Two input transducers disposed on the surface in parallel spaced apart relation produce surface acoustic waves in the body in response to the application of signals to the input transducers. A row of output transducers is disposed on the surface between the input transducers. Individual output transducers are offset from one another by amounts related to the wavelength of the surface acoustic wave so that at or near only one of the output transducers will the two surface acoustic waves from the input transducers cancel each other. An analog circuit and a digital circuit for ascertaining which output transducer experiences maximum cancellation to afford a determination of the delay difference between the two signals applied to the input transducers.

Abstract: The invention relates to bulk or surface magnetostatic wave devices. The invention provides in the ferrimagnetic substrate of such a device, at least one area with absorption increased by a treatment consisting in local sanding of the substrate or its support to produce several defects by the impact of abrasive particles. The invention is applicable to magnetostatic wave lines and filters.

Abstract: That face of the non-epitaxied substrate of high resistivity which supports the junction 3 formed by the planar method is treated by a mesa attack in such a way that it is smaller than the opposite face 7. An insulating ring 4 covers the periphery of the junction and projects beyond the substrate. This ring has external dimensions smaller than those of the face 7 beyond which it projects. A metallic layer 6 ensuring an ohmic contact covers in particular the lateral walls of the diode created by the mesa attack except for those zones of these walls beyond which the insulating ring 4 projects. This metallization of the lateral walls acts as an electrode and connects the diodes generally formed on one and the same substrate to one another.

Abstract: A surface-acoustic-wave filter for a channel selection tuning system of a television receiver includes at least two comb filter elements, each of which comprises an input transducer provided on a piezoelectric substrate and adapted to convert an input electrical signal into an elastic surface wave, and first and second output transducers disposed on the substrate for receiving the elastic surface wave propagating in the same direction from the input transducer. The first and second output transducers are positioned from the input transducer with different distances. The transducers of the two comb filter elements are so designed that the respective comb filter elements respond to frequencies of different program channel bands over for example VHF and UHF bands.

Abstract: A transducer region and lead-out electrodes connected to the transducer region are formed on one main surface of a surface acoustic wave substrate and a sheet having a thickness directionally conductive property and a plane directionally insulating property is layered on the one main surface of the substrate through a spacer. The spacer achieves a function for forming a necessary gap in the transducer region between the sheet and the substrate and a function for adhering the sheet onto the substrate. The lead-out terminals are connected through the sheet to the lead-out electrodes by virtue of the thickness directional conductivity of the sheet.

Abstract: A monolithic surface acoustic wave (SAW) signal processor which combines the functions of acoustic wave interaction, nonlinear product mixing, and integration, together with rapid-scan readout capability, which may be used, for instance, in correlation of amplitude and/or phase coded signals of a duration order of magnitude larger than the total propagation delay time of the SAW device, includes launching transducers at opposite ends of an interaction region, and a plurality of interaction taps, each tap comprising a Schottky barrier field effect transistor (FET), the sources and drains of the FETs being connected in common, but each FET gate being isolated.

Abstract: A beamforming apparatus is provided for processing the outputs of a linear rray of spaced apart receiving elements. The beamforming apparatus includes a surface acoustic wave device which has a pair of transducers mounted on a substrate in a spaced apart relationship. Each transducer is capable of receiving and converting an electrical chirp signal into an acoustic signal for propagation across the surface of the surface acoustical wave device. A plurality of taps are mounted on the substrate in a spaced apart relationship between the pair of transducers for receiving, sharing and converting the acoustic signals back into electric signals. Each tap is adapted to receive a bias voltage. A device is provided for mixing the signal from each tap with a signal from a respective receiving element so as to produce a plurality of mixed output signals, and another device is provided for summing the mixed output signals so as to provide a summed output signal.

Abstract: An apparatus is provided for processing the outputs of a two dimensional nar array of spaced apart receiving elements. The receiving elements are grouped and spaced apart in rows, which may be horizontal and vertical however, the rows may be in other directions provided they lie within a plane. The apparatus includes a plurality of surface acoustic wave (SAW) devices, each SAW device corresponding to a respective horizontal row of receiving elements and being capable of producing a plurality of horizontal phase shift outputs which linearly correspond to the number and horizontal spacing of receiving elements in a respective horizontal row.

Abstract: A tag transponder which is capable of receiving a signal from a transmitter and re-transmitting the signal after a delay. The incident electromagnetic wave from the transmitter is converted into an acoustic wave in a piezoelectric member of the tag, the acoustic wave traversing the piezoelectric member before re-transmission as an electromagnetic wave; the lower velocity of the acoustic wave compared with the electromagnetic wave provides the delay between the signal received and transmitted by the tag. During the signal pulse from the transmitter the tag continuously re-transmits the signal, and the re-transmitted signal from the tag is sustained after cessation of the signal from the transmitter for a sufficient duration to be distinguished from other transient reflected signals.

Abstract: An acousto-electric convolver having a relatively long effective interaction region for counter-propagating surface acoustic waves and, therefore, a relatively large time-bandwith product implemented by distributing a coupler, such as a multistrip coupler or an array of interdigital transducer taps, over a plurality of parallel-connected single-channel acousto-electric convolvers.

Abstract: An acoustic surface wave device comprises a transducer including an interdigital electrode formed on the surface of a piezoelectric material substrate and cooperative with the same for converting an electrical signal into an acoustic surface wave and vice versa. The interdigital electrode comprises at least two divided comb shaped electrodes divided in the propagating direction of the acoustic surface wave and a common comb shaped electrode commonly coupled in an interdigital manner to the two divided comb shaped electrodes. Thus, the above described two comb shaped electrodes are disposed such that both divided electrodes arranged in succession in the propagating direction of the acoustic surface wave while the fingers of both divided electrodes extend in the same direction and the common comb shaped electrode is disposed such that the fingers of the common comb shaped electrode are interdigitated with the fingers of both divided comb shaped electrodes.

Abstract: A surface wave phase correlator comprises a pair of substantially identical launch and receiving filter electrode patterns disposed on a common piezoelectric substrate. The correlator is employed with receiving and processing circuitry in a monopulse radar system to provide relative phase information for target calculations by a digital processor. Fast rise and fall times for the correlator output signals enable rapid digital processing of incoming target signals.

Abstract: A surface acoustic wave (SAW) device having a substrate of desired material is vacuum encapsulated in a structure fabricated from the same material as that comprising the substrate.

Abstract: The invention relates to piezoelectric devices employing a piezoelectric layer deposited on a substrate devoid of piezoelectric properties at ambient temperature. The device in accordance with the invention is provided with a piezoelectric layer made from a mono-atomic crystalline material, namely selenium. The invention is applicable to the excitation of surface elastic waves along non-piezoelectric substrates, to the excitation of bulk elastic waves and to the detection of infrared radiations.

Abstract: Signals extracted from the taps of a surface acoustic wave (SAW) device, as a consequence of a single wave propogating therein or as a consequence of interaction between a pair of waves propagating therein, are processed by linearly-controlled nonlinear product mixing and/or amplifying devices, to provide output signals in a serial chain of chips of RF, the magnitude of chips being dependent upon unique, selected bias applied to corresponding ones of the devices. The devices may be diodes operating in a bias range to provide impedence greater than the capacitive reactance impedance of the taps to which they are attached, thereby providing a linear RF voltage to DC bias current characteristic, while at the same time providing a nonlinear DC voltage to DC current characteristic for RF product mixing (where used); or the devices may comprise transistors, either field effect or bipolar, with similar suitable bias considerations when linearly-controlled product mixing is desired.