Abstract: Circuit arrangement for dynamic real time testing of a synchronous digital circuit having a clock pulse input, a stimulus input and a circuit node at which a digital test signal is produced after a time delay of .tau. seconds relative to the time of receipt of a signal at the stimulus input. The arrangement includes a clock pulse generator for generating clock pulses; a transmitter device connected to the clock pulse generator and including a counter for counting the clock pulses and a digital signal generator for generating a reproducible digital stimulus signal having a length corresponding to a predetermined count of the counter. The transmitter device is connected for coupling a number of clock pulses corresponding to the predetermined count of the counter to the clock pulse input of the digital circuit and for delivering the digital stimulus signal to the stimulus input of the digital circuit in synchronism with the clock pulses coupled to the clock pulse input.

Abstract: An integrated, micro-optical device for use in combination with a monomode fiber, a laser and a photodiode. A common substrate includes means for connecting the fiber, laser and photodiode to the device. A film waveguide is disposed on the substrate and presents a first beam path between the means for connecting the fiber and the means for connecting the photodiode. A refraction grating is disposed in the first beam path of the film waveguide. A second beam path is present by the film waveguide between the means for connecting the laser and the refraction grating. The refraction grating is constructed and positioned on the substrate so that the refraction grating transmits radiation coming from the fiber toward the photodiode and deflects radiation coming from the laser in the direction toward the fiber.

Abstract: Method and apparatus for detecting defects in an optical cable composed of a series of cable units. Light pulses are sent through one cable conductor and returned to the starting end via a second conductor and an electrical signal representative of the light intensity exiting the second conductor is derived. The electrical signal is applied to a sensitivity control circuit which is switched through a succession of sensitivity levels starting from a minimum level and proceeding to a maximum level. Each sensitivity level corresponds to the attenuation produced by a cable composed of a given number of cable units and is associated with a particular ratio between the output signal provided by the sensitivity control circuit and the electrical signal applied thereto.

Abstract: An automatic information transmission system for a mobile object, the system including a response unit arranged to be carried along with the mobile object, and an interrogation unit arranged to be disposed alongside the path of movement of the mobile object for movement of the response unit past the interrogation unit. The interrogation unit is arranged to emit a carrier signal at a first frequency and to receive a signal at a second frequency different from the first frequency.

Abstract: In a method and apparatus for determining, in a system having a transmitting end and a receiving end, displacements of image features occurring between successively transmitted image sequences, by the operations of: determining, at the receiving end, peak values of pixel correlation between successively transmitted image sequences; deriving representations of estimated displacement values from the peak values of pixel correlation; and producing representations of optimized displacement values by a recursion operation which includes recursively deriving a correction value and adding the correction value to an existing estimated displacement value to form a new estimated value, the correction value is derived by performing a mathematical division operation in which the dividend is a selected function of pixel values in successive image sequences and the divisor is proportional to the average of a first value resulting from crosscorrelation of successively transmitted image sequences and a second value resulting

Abstract: A four-port network which is connected to a microwave antenna feed horn for separating four signal paths associated, in pairs, with two polarizations and two frequency bands, and with the network also being utilized for the derivation of antenna tracking signals according to the monopulse principle. A conductor is disposed along the longitudinal axis of the waveguide connecting the antenna feed horn with the four-port network, with this conductor extending, on the one hand, to the region of the antenna feed horn throat and, on the other hand, into the four-port network so as to couple in signals of a higher order mode for the derivation of the antenna deviation signals.

Abstract: A broadband switching network in matrix form composed of a plurality of rows and a plurality of columns, and including a plurality of crosspoint switching circuits each having an input and an output and each associated with a respective row and a respective column; a plurality of input circuits each associated with a respective row and connected to the input of each switching circuit associated with the respective row; and a plurality of output circuits each associated with a respective column and connected to the output of each switching circuit associated with the respective column. Each crosspoint switching circuit includes a transistor connected in common emitter configuration and control elements connected for applying to the emitter of the transistor a potential controlling the switching state of the crosspoint switching circuit and each input circuit and output circuit is a decoupling circuit.

Abstract: A method for transmitting communications services signals in time division multiplex operation with multiple access via a satellite equipped with a plurality of receiving and transmitting units between which any desired associations can be made by means of a switching matrix. A plurality of received communications services signals are switched through to at least one transmitting unit, where they are initially demodulated, then stored as pulse bursts and thereafter read out of a memory continuously at a lower bit rate than the pulse bursts had previously, to finally be transmitted as modulated data in the form of at least one continuous bit stream.

Abstract: A system for transmitting television signals on a radio link. The system includes a transmitter having a modulator for modulating a carrier signal to produce a vestigial sideband amplitude modulated signal for transmission. The modulator includes a first converter for converting the frequency of video signals to an intermediate frequency and a second converter for converting the intermediate frequency of the video signals to a radio frequency. The system further includes a receiver having a demodulator for demodulating a received vestigial sideband amplitude modulated signal. The modulator includes a Nyquist filter connected between the first and second converters, and the demodulator includes a filter having a rectangular characteristic for processing the signal to be demodulated.

Abstract: A dual band polarization filter can be produced at low expense includes two hollow waveguide sections arranged one behind the other. A fin-type conductor structure is provided in each hollow waveguide section. The fin-type conductor structures produce polarization and frequency band separation of the signals fed into the hollow waveguide sections, these signals being associated with two different frequency bands and two polarization directions.

Abstract: Method for the interpolative conversion of an analog input signal to a digital output signal including forming an intermediate signal from the input signal; integrating the intermediate signal; sampling the integrated intermediate signal at a sampling frequency which is a multiple of the Nyquist frequency to form a sampled signal; quantizing the sampled signal with an amplitude resolution corresponding to one bit to form a quantized signal; forming a feedback signal from the quantized signal, the feedback signal comprising pulses the peak amplitude of which can be one of two representative values and which return to a mean value within an interval equal to one period of the sampling frequency; combining the feedback signal with the input signal to form the intermediate signal; passing the quantized signal through a digital lowpass filter; and sampling the output of the digital lowpass filter to produce a PCM signal, the PCM signal constituting the digital output signal.

Abstract: A reflection phase shifter connectable to a waveguide for shifting the phase of a high frequency signal received from the waveguide. The phase shifter includes a waveguide section having two pairs of opposite side walls and an end wall forming a short-circuit. The side walls define a cavity and an opening opposite to the end wall for communication with the waveguide. The waveguide section has a broad dimension between one pair of opposite side walls corresponding to the width dimension of the waveguide and a narrow dimension between the other pair of opposite side walls which is smaller than the height dimension of the waveguide. A switchable semiconductor arrangement, including a switching semiconductor element and a housing for accommodating the switching semiconductor element, is adjustably mounted in a side wall of the waveguide section and penetrates into the said cavity with a controllable penetration depth for tuning said waveguide section for a desired phase angle shift.

Abstract: A microwave ring hybrid on a dielectric carrier substrate is provided with connecting arms designed in microstrip technique. The ring of the hybrid comprises a slit line made in a conductive layer on the side of the carrier substrate opposite that on which the strip conductors of the microstrip lines for the connecting arms are disposed.

Abstract: A method for transmitting digitally coded analog signals which are combined in coding blocks in a digital packet multiplex system permits transmission of coding blocks having a length which does not correspond to the normal useful packet length. In such an instance, packets having a different content are generated and information identifying such packets is transmitted to the receive side of the system in the form of a designated number of bits in the existing available transmission capacity of the beginning of the packet, so that the beginnings of the coding block can be recognized at the receive side.

Abstract: A potential free actuation circuit for a pulse duration controlled electronic power switch having a control electrode and two major electrodes, the circuit including a driver stage having a control input and two major electrodes, and a pulse transformer connected for supplying control pulses to the driver stage for turning the power switch on and off. The driver stage and pulse transformer are connected and operated so that when the power switch is being turned off, its control electrode is placed at the potential of one of its major electrodes to thereby achieve greater freedom from disturbance, and so that the power switch is actuated with very low resistance by the driver stage, resulting in very short switching times which lead to low switching losses.

Abstract: A switching regulator whose switching transistor is controlled by a pulse width modulator wherein an electronic switch is provided which connects the potential carrying output terminal of the switching regulator with a control input of the pulse width modulator (PWM) as long as energy is flowing out of the smoothing capacitor at the output end of the switching regulator. This arrangement permits detection of the average value of the output voltage without the need for phase integration members.

Abstract: A method and apparatus for deriving control signals for enabling an antenna to track a signal source and this antenna is operated to produce at least one beam having a maximum on the boresight axis and one beam having a minimum on the boresight axis, by deriving a sum signal associated to the beam having a maximum on the boresight axis and a difference signal associated to the beam having a minimum on the boresight axis, sequentially and cyclically varying the relative phase relationship between the difference and the sum signal among four different phase values, and combining the sum signal with the difference signal for producing signals constituting a source of the control signals for enabling the antenna to track the signal source.

Abstract: A cooling system for communications equipment includes a closed container for housing the equipment and protecting the equipment against environmental influences. The container has an outer wall made of heat conductive material and is constructed for at least partial burial in the earth and for a heat transfer relationship therewith. A fluid filled conduit system includes conduits disposed outside the container and in heat transfer relationship with the outer wall thereof. The conduits outside the container are arranged to be buried in the earth for a heat transfer relationship with the earth. Heat conducting means are in thermal contact with the equipment and the container wall for transmitting heat generated by the equipment to the wall and to the conduit system. Thus, heat generated by the equipment is transferred to the fluid and heat in the fluid is transferred to the earth, and the fluid is circulated in the conduit system solely due to temperature and density variations of the fluid.

Abstract: The present invention relates to a method for automatically regulating the HF output power of a high frequency amplifier wherein a regulating voltage is utilized to produce a control voltage or a control current for controlling the gain of the amplifier, a first voltage which depends on the HF output power is derived from the supply voltage and/or from the supply current of the current supply device providing the power required to generate the HF power; the regulating voltage is formed of two components, with the first component being generated from the first voltage and a first reference voltage, and with the second component being generated from a second voltage which depends on the control voltage or on the control current generated by the control voltage and from a second reference voltage; and that for high HF power essentially only the first regulating component is active and for low and medium power, whose range approximately covers the linear operating range of the amplifier, essentially only the seco

Abstract: A stabilized microwave oscillator having a selected operating frequency range, composed of a rectangular waveguide dimensioned to have a cutoff frequency above the selected operating frequency range, at least one active semiconductor element and components connected for supplying a direct operating voltage to the element, mounted in the rectangular waveguide, a transmission resonator, and a coupling device coupling the rectangular waveguide to the resonator, the coupling device including a waveguide section having a length of about .lambda./2, where .lambda. is the wavelength of the center frequency of the operating frequency range, and dimensioned at least in part to operate as an evanescent mode waveguide and/or a waveguide having a cutoff frequency in the vicinity of the upper end of the selected operating frequency range.