Abstract: A surface acoustic wave (SAW) device includes a SAW element disposed on a printed circuit. The printed circuit has an insulation substrate having input and output wiring conductors and input side and output side grounding conductors formed thereon. Interdigital transducers of the SAW element are connected to the input and output wiring conductors. The input side grounding conductors and the output side grounding conductors are disposed apart from each other with an isolation gap inbetween, thereby obtaining desirable filtering characteristics by suppressing undesirable coupling between input side and output side caused by a feed through electromagnetic wave.

Abstract: The tuning device comprises a hollow cylindrical part and a moving rod which penetrates a cavity by passing from one side to the other of the hollow cylindrical member. This cylindrical member is fixed and integral with the cavity. It has an end located within the cavity, the end being longitudinally cut to form n slots (n being an integer greater than 1) for forming n elastic members, which are covered with an electrolytic silver deposit. Joined silver contacts are welded to the end of the elastic members to provide the contact with the moving rod and prevent poor conduction of surface currents due to wear to the electrolytic deposit at the contacts.

Abstract: A rectangular wave guide H-elbow bent across the narrow side of the wave guide and having its outer corner flattened by a symmetrically angled conducting plane. The present invention provides for the reduction of the reflection factor in such elbow by providing that the relative corner flattening of the wave guide produces a value of x.sub.H /a greater than 0.73 wherein a is the length of the wide side of the wave guide and x.sub.H is the distance from the apex of the wave guide before it is flattened by the conducting plane to the junction of the conducting plane with the narrow side of the wave guide. Furthermore, capacitive loading means of cylindrical form are arranged in the area of the geometrical median w of the bend of the wave guide and being in the form of conductive cylinders 1 or 3 as illustrated in FIGS. 2 and 3.

Abstract: An elastic surface wave filter for use as an intermediate frequency filter in a color television receiver, comprising an input electrode provided on a piezoelectric substrate plate for converting an electric signal into elastic surface waves propagating through the surface layer of the piezoelectric substrate plate, a propagation path for the elastic surface waves in the piezoelectric substrate plate and an output electrode for converting the propagated elastic surface wave into an electric signal, wherein the fingers of the input electrode are so arranged that the position at which the overlap of the interleaved fingers is maximum is farther with respect to the output electrode than the middle point along the lengthwise direction of the input electrode and wherein the pitch between the adjacent interleaved fingers is non-uniform on both the sides of the position of the maximum overlap, whereby desired group delay and amplitude characteristics for predetermined frequencies are easily and simultaneously obtain

Abstract: The treatment is directly effected on the waves propagated. Zones, for creating interruptions in propagation, are created on the useful surface of the propagation material. Several parallel tracks for propagating the elastic waves are thus delimited by these zones, the length and width of which are selected in dependance upon the required treatment.

Abstract: A microwave distributed-constant filter of a band-pass characteristic having at least one attenuation pole comprises resonator rods, each of which has an open and a shorted end and of which two first are inductively coupled in series through at least one second resonator rod. The first resonator rods are capacitively coupled direct to each other with a projection attached adjacent on at least one of the first resonator rods to the open end thereof. The first resonator rods may be coupled directly to input and output terminals of the filter. Alternatively, two third resonator rods may be interposed between the respective ones of the first resonator rods and the input and the output terminals. The third resonator rods may be inductively coupled direct to each other.

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: A tuning apparatus and a method of producing the same. The tuning apparatus comprises a base having a recess for receiving a capacitor therein, and coils mounted on the base, wherein the front ends of the comb teeth of two comb-shaped formed parts obtained by press-working an electrically conductive metal sheet are received in the recess and are fixed in position by pouring resin into the recess, the roots of the comb teeth of the comb-shaped formed parts being then severed, thereby separating the comb teeth from each other to provide independent external terminals. The comb teeth include connector comb teeth whose ends are directly connected to the capacitor terminals, and a presser tooth which urges the capacitor toward the connector comb teeth.

Abstract: An electro-mechanical filter comprises an inlet electro-mechanical transducer (12) an outlet electro-mechanical transducer (14) and a mechanical filter constituted by a series connection of resonator bars (1 to 11) which are interconnected by couplers (20 to 29). The bars are half a wavelength long at the central frequency of the pass-band while the couplers are one-quarter of a wavelength long. Instead of being connected to the ends of the bars, the couplers are connected to recessed stepped flats (40) located near the ends of the bars. The positions of the flats (40) are determined to be close to nodes in the first few orders of partials in bending mode vibration of the bars. This has the effect of greatly attenuating the excitation of such parasitic bending modes of vibration. Clearance to enable the couplers to reach the flat (40) is provided by a more deeply stepped positioned flat (41) extending to the end of the rod. Such filters may be used in terminals for analogue transmission systems.

Abstract: In the illustrated embodiments, the space required for a transversal filter with a given number of evaluation factors is reduced by providing valuator circuits embodying such factors as inputs to each successive capacitor element of a charge shifting device. In one mode of operation the signal to be filtered is sampled via the valuator circuits on each charge shift cycle while readout from the series output occurs on alternate cycles. Since the readout scanning frequency is a submultiple of the input sampling frequency, the filter is well suited as a low-pass filter.

Abstract: In a band pass filter having a plurality of helical resonators each including a quarter-wavelength winding, at least two of the helical resonators are substantially shielded from each other by a partition wall, while the corresponding two quarter-wavelength windings which are shielded from each other are electrically connected to each other through a lead line which is insulated from the shield casing, thereby improving the cut off characteristic of the filter to cut off the applied signal more rapidly in the high frequency region of the band being filtered than in the low frequency region.

Abstract: For widening the temperature range of a reflective array device configured on a substrate having an anisotropic temperature coefficient of delay, such as ST-quartz material, so that the signal strength does not decrease appreciably as the temperature of the device is changed over a broad range, the structural shape of the reflective array is configured such that the reflection angles of the discontinuity-creating surface structure vary across the reflecting edges of the discontinuity stripe (e.g. groove or rib) pattern. In one embodiment, the stripe pattern of the grating may be varied so that the reflection angles vary for alternating stripes. In another embodiment, opposite edges of a stripe may be non-parallel so that the reflection angles vary for each stripe. It is also possible to amplitude weight the frequency response characteristic of a grating by controlling the physical structure of the individual stripes of which a grating pattern is formed.

Abstract: A delay network, having a chain of all-pass sections, each comprising two separate branches, a resistive and a capacitive branch, which terminate in amplifiers with negligible signal consumption whose output signals are combined. This enables an analog delay network to be realized in integrated circuit technology.

Abstract: To improve the effect of a filter circuit for the harmonics, which contains an L-C-R series resonant circuit in at least one loop, a variable supplementary current excitation which compensates the residual harmonic current in the consumer arrangement at least approximately, is coupled into the series resonant circuit, the supplementary current excitation preferably being supplied by a compensation transformer which is controlled by the current in the loop, the compensation transformer being excited by a source and controlled by an auxiliary transformer arranged in the loop.

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.

Abstract: A SAW signal processor includes a plurality of FET taps having individually programmable source-drain bias which controls both the amplitude and the phase of the mixing efficiency of internal product mixing of waves passing beneath the tap, in dependence upon the amplitude and polarity of the bias, the gates of the FETs may be interconnected so as to provide a summation of correlation at the output. Embodiments include multi-FET taps formed on substrates that are both semiconductive and piezoelectric, such as n-type epitaxial gallium aresenide, and ZnO coated silicon. Simple biphase and weighted biphase of phase-shifted tap pairs, for complete phase control, are disclosed.

Abstract: A multiple track acoustic surface wave filter processes input signals successively flowing in coupled resonant acoustic tracks, each track being realized between pairs of surface wave reflectors in the surface of a planar piezoelectric substrate.

Abstract: An electromechanical filter having two transducers and a mechanical filter vibrating in longitudinal mode, which includes a plurality of resonators connected to each other by coupling rods. The resonators are arranged in two sections and staggered, and the coupling rods connecting two resonators are welded on flat portions provided at the ends of the resonators, each end resonator is connected to the respective transducer through a coupling rod secured to the end face of said resonator adjacent the flat portion, at a point located in the symmetry plane of the resonator, and the coupling rod which connects the end resonator to the next resonator is secured on the flat portion so that the middle of its welded length lies in said symmetry plane.

Abstract: The invention relates to electrical filters comprising piezoelectric crystals.When very considerable variations in slope are required in the transmission curve of filters of this type, it is necessary to use a plurality of crystals having very different equivalent self-inductances, some of which are impossible to obtain. The invention overcomes these limitations by using only crystals (X'.sub.1, X'.sub.2, X'.sub.3 . . . X'.sub.7) having feasible self-inductances and by establishing the desired self-inductances by using transformers such as T.sub.3.The filters according to the invention may be used in particular for the same applications as JAUMANN-type filters in telephone communications.

Abstract: An electrical phase shifting circuit element of the reflection type including a quadrature coupler branch network, a matched pair of selectively coupled transmission lines and an electrical switching element corresponding to each pair of transmission lines, all being separated distributively from each other and a ground plane by a dielectric material, is disclosed. One end of one transmission line of each pair is connected to a corresponding phase splitting port of the quadrature coupler and another end of the other transmission line of each pair is coupled to the switching element which is preferably a pin diode. The pin diodes may be governed by a common switching signal to electrically connect and disconnect the another ends of the other transmission lines to the ground plane.