Abstract: Surface acoustic wave devices are disclosed which have enhanced reflectivity gratings with conductive stripes between grooves in the substrate or conductive stripes within the grooves. For lithium niobate substrates, aluminum stripes coupled together and positioned between grooves or unconnected and positioned within the grooves are preferred. For quartz substrates, gold stripes within the grooves are used. Methods for fabricating such structures are also disclosed.

Abstract: A band pass electromechanical filter of the type comprising an input electromechanical transducer and an output electromechanical transducer and a mechanical filter vibrating in compression-extension mode, disposed between said transducers and comprising a plurality of cylindrical resonators connected to one another by coupling rods, each resonator being formed with a flat portion at the end(s) upon which at least one coupling rod should be secured, each coupling rod being welded onto said flat portion along one generatrix, said generatrix being parallel to the resonator axis, each coupling rod having its end in abutment with a shoulder which terminates the flat portion, the cross-sectional area of the resonator outside the flat portion being equal to the sum of the cross-sectional area of the resonator in the section comprising the flat portion and the cross-sectional areas of the coupling rod(s) secured on said flat portion.

Abstract: A surface elastic wave device comprising a substrate of an insulating material, a thin film of a piezoelectric material provided on said substrate, input transducer means for transmitting surface elastic wave, and output transducer means for receiving the surface elastic wave. At least one of the input and output transducer means includes a comb-like electrode which comprises interdigital fingers, and a plurality of electrodes which extend across the interdigital fingers in opposing relationship with the comb-like electrode, with the thin film being interposed between the plurality of electrodes and the comb-like electrode. The output transducer means may be arranged to receive or eliminate only surface elastic wave which is permitted to propagate in a direction which is different from that perpendicular to the longitudinal direction of the aforementioned interdigital fingers.

Abstract: Filter chain comprising at least two cascaded duals, each provided with two acoustically coupled resonators, only one of the two resonant frequencies of each of the duals falling within the filter pass band; the duals are convex at least on one side so as to render the acoustic coupling between the resonators so strong that the distance between the two resonant frequencies of the dual is as great as possible.

Abstract: A structure consisting of a semiconductive device e.g. an IMPATT diode destined to transmit high frequency electromagnetic waves through a radial waveguide integral with the structure, forming a "easy to handle" unit. A fabrication process allowing a large number of units to be made utilizing batch processing techniques, is provided. The process includes forming a plurality of mesa diodes on a semiconductor wafer, coating the wafer with a first insulating layer (filling the intervals between the mesa tables), then depositing on the wafer a plate of a solid dielectric with openings for access to the upper part of diodes. The diodes are spaced enough to allow forming around each of them a radial waveguide using a portion of the solid dielectric for propagation medium and for walls, on one hand a metallization extending the biassing electrodes of the upper parts of diode, and on the other hand, a metallic base supporting the assembly after grinding of the substrate of the wafer.

Abstract: An impedance element is disclosed which is formed with an electro-elastic surface wave transducing device composed of a substrate for the propagation of an elastic surface wave and an electro-elastic surface wave transducer disposed on the substrate for converting an electrical signal into an elastic surface wave or vice versa. The impedance element has a frequency-impedance characteristic that it exhibits a sufficiently high impedance in a predetermined frequency band but a sufficiently low impedance in the other frequency bands.Further, a band-rejection filter is disclosed which includes the abovesaid impedance element and has a band-rejection filter characteristic dependent upon the frequency-impedance characteristic of the impedance element.

Abstract: A filter connector is disclosed for reducing electro-magnetic interference. The connector may be in the form of an adaptor which is mounted between mating plug and receptacle members of electrical connectors, such as the type utilized in the telephone industry. The adaptor comprises a monolithic ceramic capacitor mounted between the termination ends of plug and receptacle connector members, with the edges of the capacitor disposed between the two rows of contacts in the connector members. The capacitor has a plurality of parallel, spaced live electrodes on its opposite faces engaging the contacts in the connector members. At least one ground plane is embedded in the ceramic substrate of the capacitor, and is coupled to the housing of the connector members. Other connector and capacitor circuit configurations are disclosed.

Abstract: An arrangement of charge transfer devices comprising a main signal transfer path defined by first and second sets of charge transfer electrodes, and an auxiliary path independent of the main path including a predetermined number of electrodes. Capacitances are respectively associated with the electrodes forming the first and second sets of electrodes of the main path, and with the electrodes of the auxiliary path. The electrodes of the auxiliary path are connected to the one of the sets of electrodes of the main channel to establish a desired relationship (e.g., balance) between the capacitances of the first and second sets of electrodes.

Abstract: The IF portion of a television receiver includes a surface acoustic wave filter comprising at least two conductors having electrodes extending therefrom to form comb-shaped elements mounted on one surface of a piezoelectric substrate. Respective electrodes of the comb-shaped elements are interleaved in alternated relationship to form a transducer for launching an acoustic signal along the surface of the substrate in response to an electrical signal coupled between the two conductors. The overlap of each pair of alternated electrodes is substantially uniform throughout the transducer. The transducer includes two end portions and a center portion between the end portions. However, because the location of the center of each pair of alternated electrodes from the location of the center of an adjacent pair of alternated electrodes is substantially the same throughout the transducer, the transducer is continuous.

Abstract: A surface acoustic wave apparatus is disclosed in which a conductive earth pattern is formed on almost all the upper surface of a header, a surface acoustic wave element is provided on the header through the conductive earth pattern, and the conductive earth pattern is separated between an input side earth pin and an output side earth pin.

Abstract: A charge-coupled analogue delay line has a plurality of analogue storage locations, and a gating means, which may include charge-coupled shift register, for enabling input to and output from each of the storage locations in turn. The storage locations are formed on a semiconducting substrate and each has a diffused zener diode to act as a source of minority carriers and a priming electrode for drawing off and holding a charge of minority carriers from the zener diode. A sample-holding electrode, upon receipt of a gating signal by a gating electrode, receives from the priming electrode and holds a charge of minority carriers of magnitude indicative of the magnitude of the signal to be stored. An output electrode is arranged to transfer the charge held by the sample-holding electrode to a diffused output channel.

Abstract: A device for treating electrical signals by correlation or convolution, by means of elastic surface waves. It comprises a semiconductor substrate on which a network of Schottky diodes is formed and which, in one embodiment, is covered by a thin layer of piezoelectric material. The end faces of the device each carry an electrode. The piezoelectric surface carries an electromechanical transducer at each of its ends. This device provides for the memorization of a reference signal applied to one of the transducers and for the correlation or convolution of that signal with a second signal applied to one of the transducers.

Abstract: An electromechanical filter comprising a plurality of parallel mounted mechanical resonators which are generally cylindrical in shape with a plurality of input and output resonators operating in a bending mode and at least one intermediate mechanical resonator operating in a torsional mode and being generally dumbbell shaped with two or more cylindrical portions connected by a torsion member and with electrostrictive transducer input and output members connected to the input and output resonators so as to provide filters having wide band characteristics.

Abstract: A method for making tuned resonance passive electronic filters. The method consists of computing the values of the filter components and then using standard unmatched components that approximate the computed values in conjunction with certain components that are made variable for the purpose of tuning out the unmatched characteristics of the unmatched components. A typical filter may include several poles where each pole includes an unmatched component, such as a capacitor, and a variable component such as an inductor. Adjacent poles may be coupled by unmatched or variable inductors or capacitors. Each pole is tuned for resonance by applying the output of a signal generator to a particular pole, while shorting adjacent poles, and tuning the variable component of that pole for resonance. Resonance may be indicated by a null on an a.c. voltmeter connected to measure pole.

Abstract: A transversal filter utilizing a double tapped delay line, is provided. Input samples of analogue signals are successively introduced into a charge transfer device comprising two tapped delay lines using split electrodes. Tap weights of both polarities are provided by collecting portions of split electrodes and summed on a single bus bar connected to a reading system delivering filtered signals.

Abstract: A shielded, floating ground RF input connector assembly is provided by a conductive enclosure having an aperture in one wall. A coaxial connector is mounted with both the inner and outer conductors extending through the aperture and with the outer conductor spaced from the aperture. A conductive flange extends radially from the outer conductor within the enclosure and covers the opening of the aperture with the flange closely spaced by a member of dielectric material from the inside wall of the enclosure. Bypass capacitors are connected between the conductive flange and the enclosure.

Abstract: A reverberation apparatus is adapted for mechanical matching characteristics and comprises at least one reverberation unit comprising a plurality of lattice construction systems of coil springs for transmitting sound-frequency mechanical vibrations, each spring system of which is connected to an electro-mechanical driver transducer and to a mechanical electrical pick-up transducer. Each system of coil springs forms parts of a lattice in at least two dimensions and in the system, the coil springs are mechanically interconnected at a number of coupling points. In each system of coil springs at least some of the coil springs are connected to a rigid frame.

Abstract: A bulk acoustic wave delay line adapted to increase triple-transit signal suppression by selective aperture limiting, the device including a bulk acoustic wave-supporting body having a planar end face at each end of the bulk acoustic wave propagation path, the device also including an annular absorbing structure disposed on at least one of the end faces immediately adjacent to and surrounding a transducer for absorbing the portion of the propagating bulk acoustic wave energy impinging on an end face not covered by the transducer.

Abstract: An electronic part comprises a plastic core holder having a sectional ] shape which has an opening part and a stopper in one side and a bottom; and a plurality of drum cores having windings which are arranged in the core holder to contact the flanges of the adjacent drum cores.

Abstract: A crystalline body having two or more domains interfacing at respective domain walls is utilized as an acoustic wave device. Input and output transducers and, in some embodiments, acoustic wave reflectors, are disposed on the crystalline body such that the delay experienced, or the path followed, by acoustic waves propagating between the input and output transducers is varied by varying the positions of the domain walls. This, in turn, is accomplished by way of control signals applied across the crystalline body.