Abstract: In the transmission of a television signal containing a luminance signal between a transmitting station and a receiving station of a television system, the picture resolution at the receiving station is compatibly increased by: effecting planar prefiltering of the luminance signal at the transmitting station and a corresponding planar postfiltering of the luminance signal at the receiving station; effecting offset sampling or offset modulation of the luminance signal at the transmitting station and a corresponding sampling conversion or demodulation of the luminance signal at the receiving station; deriving an additional signal from the luminance signal for increasing picture resolution, reducing the amplitude of the additional signal at the transmitting station and transmitting the additional signal together with the original luminance signal to the receiving station; and increasing the amplitude of the additional signal at the receiving station to an extent corresponding to the reduction performed at the tr

Abstract: A waveguide junction circulator for a high power application at a high operating frequency. The circulator includes a plurality of connecting waveguides, each of which has a standard height dimension corresponding to the operating frequency; a resonance cavity; a plurality of spaced and cooled, superposed metal plates covered with ferrite discs disposed in the cavity; a magnet disposed outside the cavity for generating a magnetic field oriented perpendicular to the ferrite discs and penetrating the cavity; and a plurality of junction arms each having one end communicating with the cavity and another end forming a connection with a respective one of the plurality of connecting waveguides. The circulator has a height dimension in its region penetrated by the magnetic field that is reduced by at least 20% compared to the standard height dimension of the connecting waveguides.

Abstract: A wave two port circuit arrangement for simulating a resistive elementary port two device for use in a wave digital filter. First and second ports are each arranged for receiving input and output signals. A summing device is connected to the first and second ports and produces a sum signal which represents the sum of the input signals present at the first and second ports. A multiplier is connected to the summing device and to one of the first and second ports for producing a negatively scaled sum signal and feeding it to the one port as part of the output signal present at that port.

Abstract: A method for increasing image resolution in a compatible television system, in which system an optical image is scanned along vertically spaced horizontal raster lines by a high definition television camera, the resulting picture signal is subjected to a horizontal frequency band limitation for transmission over a transmission channel having a given bandwidth.

Abstract: A traveling wave tube transmission amplifier arrangement, including the series connection of a predistortion circuit, a preamplifier with limiter circuit and a traveling wave tube amplifier, which is provided with several stabilizing circuits. To limit the output power, a signal which is a measure of the output power of the traveling wave tube, e.g., a signal proportional to the collector current of the traveling wave tube, is fed to a threshold controller which governs a variable attenuator provided at the input of the transmission amplifier arrangement. Moreover, to provide compensation for aging effects, a remote control signal, which is determined on the basis of an intermodulation measurement, is fed to the preamplifier with limiter circuit.

Abstract: A switching regulator for supplying current to a load in order to maintain a selected voltage across the load. Current is supplied to the load from a coil which receives a train of spaced trapezoidal current pulses from an energy source. The spacing between current pulses is maintained constant while the duration of the current pulses is varied to compensate for changes tending to vary the load voltage.

Abstract: A mushroom-shaped semiconductor stripe laser, particularly with transversal, monomode light distribution and a double heterostructure comprised of a substrate, a laser-active zone, a cover layer and an electrically contacting metal layer for the cover layer with the cover layer being underetched such that a mushroom-shaped structure is formed in which the laser-active zone is constricted to a stripe-shaped region. The ratio of the width of the cover layer to the width of the laser-active zone lies in a range between two and five, and the cover layer is electrically conductively connected with the metal layer on its outer surface as well as on at least one of its side surfaces.

Abstract: A modified single-mode W-fiber with a special threshold cladding layer surrounding the inner cladding layer in order to yield a dispersion coefficient having zeros at three different wavelengths, and as a consequence typically less than 1 ps/(nm km) dispersion over a wavelength range of nearly 0.4 .mu.m.

Abstract: A circuit arrangement for detecting a current flowing over a path in a power supply device, which arrangement includes a choke having a primary winding and a measuring winding, with each winding having first and second ends and the choke being connected so that the current to be detected flows through the primary winding, and a comparison stage having first and second inputs, with one of the comparison stage inputs being connected to the measuring winding.

Abstract: An electrical device assembly system composed of plug-in circuit boards each having a plurality of plug-in connectors at an edge presenting input and output terminals. Magazines each mounting a plurality of the circuit boards are provided. The magazines each have a rear side and are disposed adjacent to one another. Each plurality of plug-in circuit boards are mounted in a respective one of the magazines so that the plug-in connectors are located at the rear side. Rear wall circuit boards are fastened to the rear sides of the magazines and include plug-in counterconnectors for mating with corresponding ones of the plug-in connectors at the edges of the plug-in circuit boards. The plug-in connectors of each plurality of plug-in circuit boards define separate regions at the rear side of each magazine. At least one rear wall circuit board is fastened to two adjacent magazines and covers two adjacent ones of the regions, one each from the two adjacent magazines.

Abstract: To establish a connection between a stationary subscriber connected to a telephone system and a mobile subscriber, call signals are transmitted via a call center, an earth radio station and a satellite to a plurality of transceivers distributed over an area. From at least one of these transceivers the call signals are transmitted to the mobile subscriber. This avoids annoying changes in delay in modulation offering trunks which are now no longer required between the call center and the transceivers as well as interference produced by such changes in delay in the simultaneous reception by two adjacent transceivers. All transceivers can therefore operate at the same carrier frequency and simultaneously.

Abstract: A method for establishing a radio connection between a stationary subscriber terminal connected to a telephone system and a selected mobile subscriber terminal equipped with a transmit/receive device. A search request filed by the stationary subscriber terminal is transmitted to a satellite which broadcasts this search request over a given area of the earth. This search request contains the number of the selected mobile subscriber terminal and the number of the stationary subscriber terminal to be called back or the identification number of a radio transfer exchange with which the stationary subscriber terminal is connected and the circuit number of the connection existing between the radio transfer exchange and the stationary subscriber terminal.

Abstract: A method for transmitting a color television signal between a transmitting station and a receiving station of a television system and for compatibly increasing picture resolution at the receiving station. In order to reduce crosstalk noise during motion adaptive picture processing of the color television signal with increased resolution, the following measures are taken: the offset modulation or offset sampling frequency is reduced; additional signals to increase resolution are limited in bandwidth at the transmitter; the chromaticity spectrum is obtained at the transmitter from a full frame sequence of the picture and is bandwidth limited at the transmitter in the direction of vertical spatial frequencies; the luminance signal and the additional signals are complementarily filtered at the receiver; and finally, at the receiver, the chromaticity spectrum is obtained from a full frame of the transmitted color television signal.

Abstract: A circuit arrangement in combination with an electronic one-way switch connected between a voltage supply and a load, the arrangement freeing the one-way switch of high power dissipation stresses during turn-on and turn-off. The arrangement includes a shunt circuit connected across the one-way switch, the shunt circuit including an inductive storage element and a first capacitive storage element; a free-wheeling diode connected for providing a current path for current through the load when the one-way switch is turned off; a second capacitive storage element connected to the first capacitive storage element; and an auxiliary voltage source connected for charging the second capacitive storage element and for causing the second capacitive storage element to drive a current through the load via the first capacitive storage element after the switch is turned off and before the path provided by the free-wheeling diode begins carrying the current through the load.

Abstract: In a microwave push-pull frequency converter having the form of a waveguide for effecting frequency conversion of a broadband microwave signal, which converter includes a converter module composed of a waveguide section and a pair of semiconductor mixer elements disposed in the waveguide section for effecting frequency conversion between a high frequency microwave signal and a low frequency microwave signal without intermediate frequency conversion, the converter further including a waveguide filter for the low frequency microwave signal connected to one side of the module, the waveguide filter includes a plurality of ridged waveguide sections and a plurality of blocking waveguide sections interposed between, and coupling, the ridged waveguide sections, and the converter module includes fastening devices supporting the semiconductor mixer elements and configured to give the coverter module the form of a ridged waveguide which permits the high and low frequency microwave signals to pass in a single mode.

Abstract: In the transmission of a color television signal containing chrominance burst and sync signals over a Nyquist channel between a transmitting station and a receiving station, a method for modulating and synchronously demodulating the television signal according to the offset modulation and offset sampling principle. The chrominance burst or sync pulses are used as a reference signal for frequency recovery at the receiving station. An additional reference signal is generated at the transmitting station and transmitted over the Nyquist channel. The additional reference signal is utilized for phase recovery at the receiving station.

Abstract: A symmetrical waveguide coupler having two signal channels for coupling a first signal having a wavelength .lambda..sub.1 and a second signal having a wavelength .lambda..sub.2 which is longer than .lambda..sub.1. The coupler includes a carrier substrate and first and second dielectric strips embedded in the substrate to form two identical dielectric waveguides which together with the substrate define a coupling region. The first waveguide has first and second arms connected to the coupling region and the second waveguide has a third arm connected to the coupling region. The second and third arms are oriented in a direction facing away from the first arm. The dielectric strips are so dimensioned and arranged within the substrate as to present an effective coupling length c.sub.1 L.sub.1 equal to .pi./.sub.2 at a wavelength of .lambda..sub.1 for coupling the first signal between the first and third arms and an effective coupling length c.sub.1 L.sub.1 equal to .pi. at a wavelength of .lambda..sub.

Abstract: In order to effect motion adaptive interpolation of nontransmitted television image sequences, each based on at least two transmitted television image sequences, the transmitted sequences are received and segmentally divided into stationary and moving components, and the displacement of the moving components is determined by picture elements. These operations are carried out by electronically segmentally dividing each sequence into background regions which are to become visible and background regions which are to become hidden due to the movement of each moving component and deriving characteristic segment information having four possible values; deriving a set of filter coefficients from the character segment information and from information obtained as a result of determining displacement; and applying the filter coefficients to a motion adaptive interpolation filter for causing the filter to generate the nontransmitted image sequences.

Abstract: A rotary microwave switch is composed of a housing having a side wall, a housing interior cavity, and a plurality of waveguide ports distributed around the side wall. A rotor having at least one rotor cavity is mounted within the housing interior cavity and an electrically conductive plate is fastened to the rotor and has at least one gap constituting a waveguide section. The gap is in communication with the housing interior cavity and the rotor cavity. The rotor is mounted for rotation, relative to the housing, into at least one operative position for causing the waveguide section to establish a signal conducting connection between two of the ports.

Abstract: A TDMA point-to-multipoint communications system composed of a central station and a plurality of substations, with multiple utilization of a transmission band and with the transmission time between the central station and the substations having a different value for each substation, is operated to effect transmission between the central station and the substations in a succession of time frames, by the steps of:transmitting from the central station, during a first time period, a succession of signal groups, each directed to a respective substation, in a sequence such that the first transmitted signal group is directed to the substation having the longest associated transmission time and the last transmitted signal group is directed to the substation having the shortest associated transmission time;transmitting a respective signal group from each substation to the central station during a second time period following the first time period, the respective signal group being transmitted from each substation at