Abstract: A bulk acoustic delay device incorporating a transmitting transducer, a substrate, and two receiving transducers is described which may reduce the amplitude of undesired received reflected bulk acoustic waves by positioning one of the two receiving transducers to receive only the reflected wave having a longer acoustic path length due to wave diffraction to provide an output signal having a normal delayed signal and an attenuated triple or quadruple transit echo signal due to destructive interference. An alternate embodiment utilizes one composite receiving transducer.

Abstract: A surface acoustic wave device having spaced tapping output transducers disposed in the path of surface acoustic wave energy propagating along a planar substrate surface from an input transducer. The device including an ion-etched groove array disposed in the planar surface between the tapping transducers to reduce acoustic wave reflections at desired frequencies within a desired passband and suppress spurious signal-producing surface acoustic wave reflections.

Abstract: A microwave low pass harmonic absorber having a main waveguide which passes a desired fundamental frequency. A plurality of shunt waveguides are disposed on the walls of the main waveguide for providing an absorptive path for the harmonic energy. Each of the shunt waveguides includes at least one ridge for lowering the cutoff frequency of the shunt waveguide. In another embodiment, the shunt waveguides include two ridges disposed opposite each other.

Abstract: A surface elastic wave filter in which Rayleigh waves experience only small attenuation and phase-shift, the number of radiating elements encountered by the surface wave during the wave propagation having a direction parallel to an axis xx through the filter, being restricted. The filter comprises at least one electromechanical transducer constituted by two metallic comb structures A and B whose teeth d.sub.A1, d.sub.A2, d.sub.A3 and d.sub.B1, d.sub.B2, d.sub.B3 are interdigitated and are arranged at either side of an axis yy in symmetrical fashion vis-a-vis a point M located upon said axis, at the center of the transducer. The filter can be used to the filtering of video-frequency signals in television circuits.

Abstract: A two stage surface wave termination for a surface acoustic wave device, such as a filter or delay line. The termination includes a wafer of an acoustically lossy, relatively hard polymeric material that is bonded to the surface of the SAW device's piezoelectric substrate between an end of the substrate and an interdigitated transducer provided thereon. A band of an elastomeric material is bonded to the substrate along the edge of the wafer nearest the transducer.

Abstract: An electrical LC resonant circuit, particularly useful for channel filters in carrier frequency technology, has a fixed-tuned coil and a capacitor tunable by the removal of layer surface portions. The capacitor is constructed as an essentially flat, self-healing layer capacitor having a relatively small number of layer surfaces and dielectric layers lying one upon the other.

Abstract: A method that permits essentially exact synthesis of a cylindrically symmetric static magnetic field of specified and fixed characteristics and either spatially uniform or non-uniform, as required, in a magnet of arbitrary, but feasible, shape and apparatus that provides such cylindrically symmetric static magnetic field.

Abstract: An electromechanical filter comprises a mechanical resonator, a pair of electromechanical transducers mechanically coupled to each other with the resonator interposed, and a pair of external matching circuits electrically connected to the respective transducers. Each matching circuit comprises a coil and a temperature-compensation capacitor connected to form a resonance circuit with the equivalent parallel capacitance of the associated transducer included therein. Resonant frequencies of the respective resonance circuits are rendered different from the passband center frequency of the filter. Preferably, the first-order temperature coefficients of the resonant frequency and the equivalent inductance of each transducer are selected to be (1) both negative and (2) positive and negative as the resonant frequency of the associated resonance circuit is rendered (1) higher and (2) lower than the center frequency.

Abstract: A transmission line is disclosed which comprises a conductive layer, a resistive semiconductor layer disposed on the conductive layer and a blocking electrode disposed on the resistive semiconductor layer. By applying a biasing voltage between the blocking electrode and the conductive layer, a depletion layer is produced in the resistive semiconductor layer, the depletion layer formed in the semiconductor layer being used as a medium for transmission of electromagnetic wave.

Abstract: The surface acoustic waves reflecting from the edges of a surface acoustic wave device, designed for low frequency application, are attenuated by placing an epoxy resin or a powder-epoxy resin mixture near the edge of the surface acoustic wave device.

Abstract: A tapped surface acoustic wave (SAW) delay line with time-resolved outputs sing piezoelectric leaky wave coupling and bulk wave amplification, and having low loss characteristics. A solid piezoelectric semiconductor is placed adjacent to a solid piezoelectric substrate. A pulsed rf input signal is applied to interdigital transducers (IDT) on the substrate. The applied signal launches a SAW in the substrate in a direction parallel to the interface between the substrate and the piezoelectric semiconductor solid. Upon reaching the interface, the SAW is piezoelectrically leaky-wave coupled across an air gap to a bulk acoustic wave in the piezoelectric semiconductor. Reflections of the bulk wave occur at both surfaces of the piezoelectric semiconductor, and piezoelectrically couples back across the air gap to excite a SAW on the piezoelectric substrate. The resultant rf output includes the normal delayed SAW pulse and additional delayed and time-resolved pulses.

Abstract: An octave band phase shifter/polarization switch is disclosed which is comprised of a plurality of serially coupled phase bits arranged to provide, in combination, a four bit phase shifter and a polarization switch capable of providing any selected one of six separate polarization senses. The device is fabricated in a stripline package and each of the phase bits is comprised of a hybrid coupler whose output ports are terminated in switchable reactances. Either packaged microwave P-I-N or N-I-P diodes are utilized as the switchable reactances, and bias voltage for the diodes is provided by means of an octave band choke, comprising a dielectrically loaded coil disposed within a center dielectric layer of the stripline package.

Abstract: An input transducer for a surface wave filter with a transfer function T(F) the inverse Fourier transform of which is a function I(t) having maxima the amplitude of which vary within wide limits; such an input transducer comprises at least two elemental transducers of which one has a pulse response comprising the high-amplitude maxima of I(t), while the other(s) has/have a pulse response comprising maxima equal to n times the low-amplitude maxima of I(t); the first is fed by the signal to be filtered; the other(s) is/are fed by a signal equal to 1/n of the signal to be filtered. Such a transducer arranged at one end of a piezoelectric substrate of which the other end comprises a wide-band output transducer, provides for the construction of high quality filters.

Abstract: A pi pin filter employs a tubular ferrite which receives a pin contact therein. The ferrite tube is metalized over at least a portion of its inner surface, at least two portions of its outer surface, and about its ends and receives the pin contact therein for electrical connection to the metalization by means of a spring contact, solder bonding or fusing. A plurality of dielectric layers extend radially of the ferrite tube and are bonded together to form an integral structure having metal capacitor plates between the layers. Some of the capacitor plates are interconnected, by a metalization to form the ground plates for connection to the metal shell of an electrical connector, while others of the metal plates located intermediate the first-mentioned metal plates are interconnected in two separate groups by a separate metalizations which, upon assembly, are fused to the respective metalized areas on the outer surface of the ferrite tube.

Abstract: Acoustic surface wave resonator device having two sets of reflector arrays on a piezoelectric substrate with structurally modified coupling transducers interposed therebetween, wherein the transducers are coupled to the standing wave resonance in the resonance cavity but are respectively decoupled from the surface wave launched by the other transducer, thereby suppressing direct coupled response without materially affecting the resonance response. In a typical embodiment, a pair of interdigital transducers are disposed between two sets of reflector arrays on a piezoelectric substrate, with the fingers of the respective transducers including intermediate off-set portions thereof. Specifically, the intermediate off-set portion in each interdigital finger extends over a distance .lambda./4, with the space between successive fingers in a transducer being .lambda./2.

Abstract: An electric filter includes a first conducting strip, a second conducting strip and two dielectric strips. The first and second conducting strips are rolled up together and are separated by the dielectric strips. The filter also includes a first terminal, a second terminal and a third terminal. One end or a point close to it of the first conducting strip is connected to the first terminal and the other end or a point close to it of the first conducting strip is connected to the second terminal so that at least a substantial part of the inductance of the first conducting strip due to its being rolled up is in series with the first and second terminals. The third terminal is connected to the second conducting strip.

Abstract: A multistrip surface acoustic wave filter having directional coupling characteristics may be used to transfer acoustic wave energy between acoustic wave channels or tracks. The devices are characterized by predetermined signal filtering pass bands, since the degree of transfer of energy is made a function of the excitation frequency. The fanned multistrip surface wave filter elements may be cascaded or weighted to provide a range of design selectivity of frequency response.

Abstract: The following specification describes a connector assembly employing a capacitor assembly having axially spaced radially extending capacitor plates carried by a ceramic or dielectric member. One plurality of plates are connected in common to the connector shell and other radially extending axially spaced plates are connected to respective contacts of the connector to form a filter capacitor for each contact. A conductive elastomer or metal spring engaging one of the common plates under axial pressure ensures a secure electrical ground connection between the plates common to the connector contacts and the shell while a metal spring preassembled to each contact at an axial position coincident with the capacitor assembly exerts a radial outward pressure to ensure an electrical connection to the capacitor plates associated with the respective contact.

Abstract: A circuit for the parallel coupling of audio frequency transmitting stations in a wave band filter construction is described, in which the wave band filter consists of two resonant circuits tuned to an audio frequency essentially free of the line harmonics, coupled magnetically to each other, and electrically separated, and in which the line-side circuit has been designed as a series resonant circuit, and the capacitor of the generator-side resonant circuit has been connected in parallel to the audio generator and to the coupling inductance of an ironless coupling transformer.

Abstract: An electronic filter circuit having controlled "Q" with variations in attenuation. A plurality of filter networks are connected in parallel between the output and the input of an amplifier in a manner such as to be capable of selectively providing negative feedback to the amplifier. Each filter network includes inductive, capacitive and resistive elements, with a potentiometer forming part of the resistance thereof. Each potentiometer is connected in series with a resistor having the same value thereas, the arm of the potentiometer being connected to its associated filter network such that the "cut" to which the potentiometer is set determines the total value of the resistance presented by the filter network in the feedback circuit. The potentiometers and associated resistors are each connected in series with each other, these series connected elements being connected in parallel between the input and the output of a unity gain amplifier.