Abstract: A two-cavity notch filter including an input terminal inductively coupled to an output terminal having a low impedance connection therebetween, a first relatively high impedance resonant tank circuit including the series combination of a circuit grounded capacitor and circuit grounded inductor having a tap point thereon, a capacitor and optionally in series therewith an inductor connected between the input terminal and tap point. The notch filter also includes a second relatively high impedance resonant tank circuit including the series connection of a circuit grounded capacitor and circuit grounded inductor having a tap thereon, and a capacitor and, optionally, in series therewith an inductor between the output terminal and tap point of the second tank circuit inductor. There is capacitive coupling between the capacitors forming the first and second tank circuits.

Abstract: An interstage coupling network is provided comprising a series connection of an even number of reactive elements coupled between the input and output terminals of the interstage network, a junction point of said series connection of inductors being coupled to a signal reference potential via a first reactive shunt element. A series connection of oppositely-poled switching diodes is coupled in parallel with a portion of said series connection of reactive elements, the junction between the series-coupled diodes being coupled to the signal reference potential via a second reactive shunt element. A third reactive element is coupled between the network output terminal and a point on the series connection of reactive elements which is remote from the input terminal of the network.

Abstract: A tuned resonant circuit including inductive and capacitive components useful as a marker in electronic marker surveillance systems, comprising a laminate of a dielectric and conductive-multi-turn spirals on opposing surfaces of the dielectric, wherein the capacitive component is formed as a result of distributed capacitance between the opposed spirals, and wherein an electrical connection is provided between predetermined opposing portions of the respective spirals.

Abstract: A switched bandpass filter includes a plurality of triple tuned bandpass filter sections coupled in parallel between an input and an output terminal and complemented by input and output parallel resonant circuits. Each bandpass filter section includes a switch such as a switching diode by means of which the filter section is either rendered active for passing or inactive for suppressing the frequency band to which it is tuned. Portions of the inactive bandpass filter sections contribute to the resulting frequency response with notches at frequencies outside of the passband of the active filter section. Thus, some components of the inactive bandpass filter sections are reused with the active filter section to gain steep out-of-band rejection slopes. In one embodiment, the switched bandpass filter employs only one switching diode per frequency band and, by reusing two-thirds of the filter components, provides a highly efficient switched bandpass filter arrangement.

Abstract: A method of constructing an LC network, and the resulting LC network manufactured by cutting and removing a predetermined pattern from a first and a second conductive sheet, leaving on each sheet a generally coil-like configuration of windings with a sufficient number of interconnections between the adjacent windings to add rigidity to the sheets, laminating these conductive sheets to opposing faces of a non-conductive sheet, thereby forming at least one capacitor, cutting and removing a pre-determined pattern from the lamination eliminating at least some of the interconnections and leaving a conductive path on the conductive sheets which is in the configuration of a coil.

Abstract: A protective circuit for reducing subsynchronous natural resonant frequency signals in a multiphase power supply system includes a damping resistor connected in series with each phase winding of the system. A resonant circuit tuned to the rated line frequency of the system is connected in parallel with each resistor so that signals having frequencies other than the rated line frequency will be damped by the resistors. An inductor can also be placed in parallel with each resistor to maximize the damping effect of each resistor at predetermined subsynchronous frequencies.

Abstract: A method of constructing an inductive-capacitive (LC) network is disclosed in which a predetermined pattern is cut from a metallic sheet to provide a multi-turn, essentially spiral-like configuration in which a plurality of interconnecting regions are left between adjacent turns. A pre-laminate is then formed by laminating one surface of the configured sheet to a surface of a sheet of dielectric material. A completed multi-turn inductor is formed by a second cutting operation in which the remaining interconnecting regions between the adjacent turns are removed. The LC network is completed by laminating a second metallic sheet to a dielectric layer overlying the completed multi-turn inductor. The first and second cutting operations and assembly of the respective sheets are performed such that any burrs resulting from the operations are directed away from the interlying sheet of dielectric material, thereby avoiding problems due to shorting out between the two metallic sheets.

Abstract: A lumped circuit loop-gap resonator is formed by a plurality of openings formed through a block of material. The openings form inductive loop elements and these are interconnected in a variety of possible networks by capacitive gap elements. String, star, ring and lattice networks are described.

Abstract: A noise filter and terminal structure therefor are disclosed. An insulator case composed of a case main body and a cap are utilized, with the case main body including coil fixing projections and capacitor position restricting ribs. A plurality of metallic terminals provide electrical connections to the electrical components within the insulator case and extend out of that case between adjacent edges of the case main body and cap. The metallic terminals are generally flat, with a generally U-shaped bent portion and a connection part extending from the bent portion. The bent portion is fitted into a corresponding concave part in the case main body. The connection part includes hook-shaped projections adapted to hold a wire, and the projections of all terminals are at generally the same level to facilitate automatic soldering.

Abstract: A band-pass filter circuit has series elements, comprising a parallel resonant circuit and a first inductance, and shunt elements comprising a series resonant circuit and a second inductance, the resonant circuits comprising variable capacitances to permit variation of the frequency over a frequency band. The second inductance may be a transformer. The variable capacitances may be constituted by a plurality of switchable component capacitances, having switches connected between the capacitances and ground.

Abstract: A four-terminal network, especially for filtering frequency bands or values, behaves as an ideal winding, therefore ensures high selectivity and, if equipped with an iron core, the possibility of carrying out switch operations. The network includes a pair of closely adjacent inductor coils having parallel turns for current in opposite directions, and equal inductance with a capacitor connected to at least one end of one of the coils.

Abstract: The invention relates to an electrical filter circuit operated with a definite sampling and clock frequency f.sub.T, such filter being made up of CTD elements, and having at least one bipolar or quadripolar resonator in the form of a self-contained conductor loop (for example, C.sub.1, C.sub.2) with unidirectional transmission behavior.Differences in the transfer capacitances of such circuits are reduced, as far as possible, in order to thereby simplify integrated manufacture as far as possible, by positioning the frequency band to be filtered out at a frequency position which lies above half the clock frequency (f.sub.T /2), or in the range from f.sub.T /2 through 3f.sub.T /2.

Abstract: A circuit having several resonant frequencies is disclosed. The capacitance between coils is used instead of discrete capacitor components. One frequency is the self-resonant frequency of a large single layer coil and another frequency is the resonance of the double layered end of the circuit. The use of such multiple frequency circuits as antenna traps and loading coils is shown.

Abstract: A circuit having several resonant frequencies is disclosed, using the interwinding capacitance between layers of coils for the tuned circuit capacitors. The use of such multiple frequency circuits as antenna traps is shown.

Abstract: There is provided by this invention a novel high power resonance filter utilizing a resistive element between two resonant branches disposed to dampen resonant harmonic currents or voltages while maintaining minimal losses at the fundamental frequency.

Abstract: A frequency selective limiter comprising a plurality of LC series-resonant filters having resonant frequencies uniformly spaced over the passband. Each filter is formed of two identical LC series-resonant sections with a diode limiter coupled between the two sections. The filters are coupled in parallel between the limiter input and the load to form two groups having alternate resonant frequencies with signals passing through one group being shifted in phase by 180.degree. relative to signals passing through the other group.

Abstract: A broadband radio frequency signal are in the range between about 5 and 400 MHz and a single phase 60 Hz AC power signal are transmitted through a cable transmission line of a cable television system. Amplifiers are powered by the 60 Hz AC signal. The amplifiers are operable as repeater stations that transmit the radio frequency (RF) signal. An RF choke connected to the transmission line separates the 60 Hz AC signal from the broadband 5 to 400 MHz signal. The RF choke includes a conductor of a preselected gauge formed in a coil having a preselected number of turns wound around a ferrite coil form. A ferrite bead is in series with the coil on a selected turn of the coil. The ferrite bead displays an RF series resistance or impedance to the inductance of the coil and reduces the series resonance of the coil. A resistor is connected in parallel to a selected turn of the coil at the opposite end of the coil and functions as a shunt.

Abstract: A crossover network is coupled to each transducer in an array of acoustic ansducers, each transducer having a different frequency band, and all of the crossover networks being coupled in parallel to a single driving amplifier. Each crossover network includes a network inductance connected in parallel with a transducer capacitance to form a parallel LC circuit, the resonant frequency of such circuit being equal to the resonant frequency of a transducer RLC series circuit. The network inductance of each network is coupled to the amplifier in series with a driver inductance and a driver capacitance, which are respectively equal to the inductance and capacitance of the RLC series circuit of a transducer.

Abstract: In an electrodeless discharge lamp of the type including an ionizable medium within a sealed envelope capable of emitting radiant energy when subjected to a radio frequency field, an oscillator for generating an output signal at a given radio frequency of 13.56 MHz, an RF amplifier responsive to the oscillator output signal, and an induction coil and a capacitor connected in series and responsive to the output of the amplifier, the coil being positioned in close physical proximity to the medium in the envelope for coupling to the medium an electric field having a magnitude sufficient to initiate ionization of the medium and a magnetic field for maintaining ionization, there is disclosed an improvement wherein a Class D amplifier drives the series connected coil and capacitor without a separate load circuit connected in the output circuit of the amplifier. A specially selected filter and matching network coupled between the Class D amplifier and the series connected coil and capacitor reduces CV.sup.

Abstract: Band-stop filter for equipment with carrier-frequency utilization of low-voltage lines, including a current-compensated choke having a closed ferrite core, two center taps, and two coil halves each of which having windings being connected to one of the center taps and wound with the same sense on the closed ferrite core, and a capacitor connected between the center taps.

Abstract: A switched-capacitor filter circuit having at least one simulated inductor and having a resonance frequency which is one-sixth of the sampling frequency as pulse-controlled switches co-operatively operable for connecting a first capacitor to a pair of input terminals during a first clock phase and simultaneously connecting a second capacitor to the output of an inverting integration circuit, followed by discharge of the first capacitor to a capacitor in the integration circuit during a second clock pulse phase, followed by a third clock pulse phase during which the first capacitor is charged from the output of the integration circuit and the second capacitor is simultaneously connected to the pair of input terminals and during a fourth clock pulse phase the second capacitor discharges to the capacitor in the integration circuit.

Abstract: An electronically adjustable capacitor (varactor), an active element such as a Field Effect Transistor arranged to exhibit negative resistance, and an inductor are arranged as a frequency tunable resonator suitable for use at microwave frequencies. The negative resistance of the active element may be adjusted to compensate for the resistance of the other resonator components such that the resonator exhibits very high Q and therefore high selectivity and low loss. The resonator may be used as a filter element in a tunable filter. Alternatively the negative resistance of the active element may be adjusted such that the resonator exhibits net negative resistance and may be incorporated in a tunable reflection type amplifier.

Abstract: An equalizer introduces into the attenuation versus frequency curve of a signal carrier transmission system compensatory bumps of adjustable magnitude and of adjustable frequency location. When the bumps are in their initial frequency locations, they exhibit the following features: (a) The middle frequencies of the bumps are each shiftable with respect to frequency by an amount equal to at least one half the frequency interval to the respective neighboring bump. (b) Adjoining bumps of equal magnitude have facing flanks which overlap and intersect at a point which is at least 0.6 of the way up the height of the bump. (c) The middle frequencies of the individual bumps are distributed within the frequency range to be equalized in at least approximate correspondence to the detail density distribution function d*. The function d* is a novel function defined herein.

Abstract: An electrical frequency responsive circuit comprising a first coil constructed of wire having an insulating coating thereon wound in a single layer about an axis of generation, and a second coil, also constructed of wire having an insulating coating thereon wound about an axis of generation in a single layer, said coils being axially related and having diameters and/or pitch to provide inductance and capacitance between the coils which is at least initially adjustable whereby the circuit is responsive to an electric signal having a predetermined electrical frequency imposed across the coils to provide frequency band suppression about the predetermined frequency.

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: A filter for a telecommunication system, designed to suppress a signal frequency F.sub.a and to transmit an adjoining frequency F.sub.b without significant attenuation, comprises a resonant cavity of prismatic shape longitudinally traversed by a conductive coil wound on a hollow dielectric core into which an adjusting screw is inserted. One end of the coil is grounded at the cavity wall while its other end is left unconnected and forms with the adjusting screw a variable capacitance C.sub.d with distributed constants; a lumped-constant tuning capacitor C.sub.1 is connected between ground and an input lead connected to an intermediate tap on the coil, the inductance L.sub.2 " of that lead and the inductance L.sub.2 ' of the coil portion between the tap and ground forming an inductive voltage divider bridged by the lumped-constant capacitor C.sub.1. The remainder of the coil, lying between the tap and the unconnected end, forms an inductance L.sub.1 which together with the distributed-constant capacitance C.

Abstract: A coupling device for a microwave tube including a first length of waveguide and a second length of waveguide of rectangular cross-section. The two lengths of waveguide are connected together and have their free ends coupled when operating to a load and to the tube respectively. The large side of the cross-section of the second length of waveguide is equal and parallel to the corresponding side of the first length of waveguide. The small side of the cross-section of the second waveguide is several times smaller than the corresponding side of the first waveguide. Two connected lengths of waveguide form a transition. The first waveguide contains an iris and the coupling device forms an assembly of matched impedance.

Abstract: A bandpass filter is described for filtering a television signal. The filter has a passband which may be selectively centered for filtering signals in one of two channels of the television receiver. The television channel at which the filter passband is centered is selectable by applying a voltage to a control terminal. The filter frequency response for each channel selected may be independently controlled and a linear phase response is realized for the selected channel minimizing distortion.