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: In an acoustic wave device having a pair of spaced apart reflectors forming a resonant cavity, each reflector consists of an array of parallel reflective elements. At least one of the reflectors is weighted not by simple withdrawal of reflecting elements from a nominal uniform array but instead by substituting reflective elements of the uniform array with elements providing both net-zero reflection at required positions and also at least partial compensation for the velocity perturbation which would be produced by such simple withdrawal. Such weighting may be used to suppress the side lobes of the reflector response and hence improve the stopband performance of the acoustic wave device and, for example, a coupled resonator filter in which that device is incorporated.

Abstract: An acoustic surface wave device including a three-phase unidirectional transducer. The transducer has three sets of interdigitated electrodes. The first and second sets of electrodes are each connected to bus bars, one on each side of the central axis of the transducer. The electrodes of the third set are connected to two bus bars one on each side of the central axis. The structure of the third set of electrodes and the bus bars connected thereto is symmetrical with respect to the central axis. The balanced structure of the transducer permits simplified impedance-matching and phase-shifting networks for enabling three-phase unidirectional operation of the transducer from a single phase electrical source.

Abstract: A surface acoustic wave filter is disclosed having an interdigitated structure of transducer fingers on a piezo substrate. Spurious signals are suppressed by employment of a slanted placement of transducer fingers at an output region of a weighted input transducer or at an input region of a weighted output transducer.

Abstract: An elastic surface wave device including interdigital finger electrodes comprising interdigital fingers each of which consists of a pair of divided finger elements having an equal width. The spacing between adjacent ones of the interdigital fingers is equal to the spacing between the pair of divided finger elements thereof. Importantly, at least one of the interdigital fingers is differentiated from the remainder of the interdigital fingers in respect of the distance from the center of the spacing between one of the interdigital fingers and that one of the interdigital fingers which is adjacent thereto on one side to the center of the spacing between the aforementioned one interdigital finger and that one of the interdigital fingers which is adjacent thereto on the other side. Furthermore, the interdigital finger electrode is designed such that the width of the respective finger elements is equal to the spacing therebetween.

Abstract: An acoustic surface wave filter element provided with two input and two output pins connected with the input and the output interdigital electrodes, respectively and an earth pin connected with a filter element shield casing is disposed on one surface of a circuit board, with the five pins extending through corresponding through holes in the circuit board to the other surface of the circuit board on which the pins are connected with corresponding conductive circuit patterns of the circuit board. The circuit patterns include a first signal pattern to be connected with one of the input pins, a first earth pattern connected with the other of the input pins, a second and a third signal pattern connected with one and another of the output pins, and a second earth pattern connected with the earth pin of the filter element.

Abstract: An elastic surface wave device includes a transducer having an elastic surface wave propagated in the direction of 75 to 133 degrees to a Y-axis on an X-cut lithium tantalate (LiTaO.sub.3) substrate.

Abstract: Electroacoustic apparatus is described incorporating a substrate having a plurality of transducers on an upper surface and a plurality of transducers on a lower surface each positioned for receiving bulk acoustic waves from a respective transducer on the upper surface wherein each receiving transducer has a predetermined acoustical path length from its respective transducer on the upper surface, means for coupling an input signal to the transducers on the upper surface, and means for coupling an output signal from the transducers on the lower surface. The invention further provides a plurality of bulk mode acoustic delay lines having predetermined acoustical path lengths which are coupled in parallel to suppress the triple transit signal.The invention overcomes the problem of spurious triple transit signals in bulk mode acoustic delay lines for input signals having a wide bandwith, such as an octave.

Abstract: A surface acoustic wave filter device having an input transducer and an output transducer, in which triple transit effects are minimized by the addition of a second output transducer spaced from the input transducer, preferably by a distance three times the spacing between the normal input and output transducers, to duplicate the triple transit path length. A triple transit signal is thereby simulated at the second output transducer, is adjusted in amplitude and phase, and is applied to a summing circuit in which the simulated triple transit signal is subtracted from a signal derived from the original output transducer, to effectively cancel the triple transit component.

Abstract: This invention provides an elastic surface wave device utilizing Bluestein-Gulyaev wave and constructed by a unitary body of a piezoelectric plate having a plurality of transducers thereon, wherein the wave propagation surface being coated with an insulating rubber and being embedded in molding by an insulating powdered epoxy resin, or whose body is attached on a unitary supporting substrate via double adhesive layers; wherein one layer is composed of one kind of adhesive resin and the other is composed of another kind of adhesive resin different from the former in ultrasonic property. This device is advantageous because it has a low spurious signal level without increasing insertion loss, and is easy to manufacture and inexpensive. This invention also provides an effective method for making the device.

Abstract: This disclosure depicts a surface wave transmitting device having a piezoelectric surface wave propagative medium and interdigitated comb-type input and output transducers on a surface of said medium. The input transducer is responsive to a source of input signals for launching on the surface of the medium surface waves of predetermined center wavelength. The output transducer receives the surface waves from the input transducer and develops output signals. The device is improved by one of the input and output transducers having at a transducer boundary or at an internal irregularity in the transducer tooth pattern a first tooth on a first comb connected to its associated bus bar. On an opposed second comb, there is provided a second tooth collinear with the first tooth but electrically isolated from its associated bus bar.

Abstract: To eliminate disturbance signals caused by the reflection from the unitary stem areas of comb-like electrodes of an interdigital transducer in an elastic surface wave device, the edges of the unitary stem areas perpendicular to the surface wave propagating direction includes at least one pair of partial edges, the positions of the partial edges in each of the at least one pair of partial edges differ by (2n+1).multidot..lambda./4 from each other in the surface wave propagating direction, and the lengths of the partial edges in the each pair are equal to each other, where n represents zero or a positive integer and .lambda. represents the wavelength of the elastic surface.

Abstract: A surface acoustic wave device having a unidirectional input transducer is provided with an input tuning circuit which eliminates the reactive portions of the device's input impedance. The input transducer has a pair of input ports, each of which exhibits an impedance A.angle..phi.. A series tuning circuit including reactances having a magnitude of A(sin.phi.+cos.phi.) and A(sin.phi.-cos.phi.) respectively, is connected to the input ports. An alternative parallel reactive tuning circuit is disclosed whose reactances are A/(sin.phi.+cos.phi.) and A/(sin.phi.-cos.phi.) respectively.

Abstract: A surface acoustic wave signal processor having a plurality of taps, each connected to an external nonlinear device are arranged in pairs, each pair having its phase center aligned for interception of propagating waves at the same transversal distance from the launching thereof, the taps having configurations so that each tap in the pair receives signals at a phase which is inverted (180.degree. out of phase) with respect to corresponding signals received at the other tap of the pair, the product mixing output of the external nonlinear device for each tap being summed with the like output for the other tap in the pair, whereby all waves intercepted by the tap pair are cancelled at the product mixer outputs, along with certain of the components of product mixing having odd-ordered exponents. Disclosed configurations include tilted taps with co-propagating waves, longitudinally aligned taps with counter-propagating waves, and co-linear taps with plural channel, transversally displaced waves.

Abstract: An elastic surface wave device for use as an electronic element such as a delay line or a filter in home-use electronic apparatus such as color television receivers and radio receivers and in industrial electronic apparatus such as electrical communication units.

Abstract: A surface acoustic wave device wherein the interdigitated fingers are capacitively weighted with decreasing capacitance from the center of the transducer to the ends thereof has an improved response in the frequency passband in that the dip therein is substantially diminished, if not eliminated, when the interdigitated fingers of the transducer are of the split-connected form except adjacent at the ends of the transducer where the interdigitated fingers are of the split-isolated form, or all of the interdigitated fingers are of the split-isolated form. The increased surface acoustic wave reflection occurring at the end fingers where the weighting capacitors are small is overcome by the decreased surface acoustic wave reflection resulting from the increased impedance of the split-isolated fingers.

Abstract: Applicants discovered that by employing selected transducer geometries, such as unbalanced dual-finger geometries, certain reflections, called "Mechanical electrical loaded" (MEL) reflections, can be generated which tend to cancel reflected waves inherently generated by surface acoustic wave devices.In particular, the disclosure is directed to a transducer for a surface acoustic wave device adapted for coupling to an electrical load and/or source. A pair of interdigitated comb electrodes are formed on an acoustic wave propagating substrate, for example a piezoelectric substrate. Means, such as input or output terminals, are provided for applying an electrical load and/or source across the pair of comb electrodes. Each of the comb electrodes has a plurality of interdigitated electrode fingers.

Abstract: An acoustic surface wave device wherein an interdigital transducer is provided which includes interdigitated electrodes of narrow width and fine spacing extending from parallel bus bars. Means are provided electrically to interconnect members of a set of electrodes at a location spaced from the bus bar from which they extend to provide multiple current paths between the bus bar and metallization elements forming the electrodes. In one embodiment, apodized electrodes are interconnected adjacent ends of electrodes of the opposite set. In split electrode transducers, the electrodes of each pair are also interconnected at the ends opposite the associated bus bar.

Abstract: The invention relates to transducer electrodes for filters or delay lines using surface wave principles on piezoelectric substrates wherein parallel mounted electrodes have interdigital fingers extending toward the electrodes and wherein feeders for the fingers have widths of one half the wave length of the surface wave at the mean filter frequency so as to equalize and eliminate reflections in the device.

Abstract: Transducer electrodes for filters or delay lines using surface waves wherein the transducers are formed by interdigital conducting films formed on the surface of piezoelectric substrates and wherein the length of the interdigital electrode fingers vary and wherein all of the fingers on at least one side are attached to an enlarged metal area which has a width equivalent to the total width of all of the electrode fingers on this side.

Abstract: An acoustic surface wave device having a substrate of a material capable of propagating acoustic surface wave energy. At least one electro-acoustic transducer coupled to a region of a surface of the substrate. The transducer has a first and a second bus bar positioned parallel and a distance from each other. A plurality of electrodes extend from each bus bar. The electrodes from the first bus bar are opposite to the electrodes of the second bus bar with the electrodes from one of the bus bars being forked and surrounding the electrode located in an opposite relationship thereto, thus, reducing substantially any synchronous reflections.

Abstract: An acoustic surface wave interaction device includes a plate of dielectric material provided with two transducers each having at least one pair of comb-shaped electrode arrays having a plurality of teeth. The teeth in one comb-shaped electrode array of each pair are interleaved with the teeth of the other comb-shaped electrode array. At least one transducer has the pair of comb-shaped electrode arrays divided into two or more pairs of comb-shaped electrode arrays which are electrically connected in series, while the length of teeth is varied so that the tip ends thereof are enveloped by a curve representing the inverse Fourier transform of the transfer function of the device. The number of pairs of interleaving teeth to be included in one divided pair of electrode arrays is determined by the length of interleaving of the teeth in order to provide each divided pair of electrode arrays with the same impedance.