Abstract: A method of recovering a signal representing the phase difference between a local carrier signal and the carrier of an amplitude and/or phase shift keyed received signal involves dividing the received signal into two cartesian oriented signal components which are a function of the phase difference and have a quadrature relationship to one another. Each pair of cartesian oriented signal components, representing one of a plurality of possible signal states, is converted into two polar oriented signal components. A decision is made as to which ones of the permitted, unfalsified polar signal components come closest to the polar signal components of the received signals. The phase difference is derived from a comparison between the result of the decision and the received polar signal components.
Abstract: The present invention relates to a method of reducing the quantity of overhead data in image coding wherein the image is subdivided into partial image regions and these partial image regions are characterized by classes. To determine the class, the partial image region is transformed by discrete transformation into the spectral range and the absolute values of the spectral coefficients are then processed in a manner such that all absolute values are compared with their visual discernibility thresholds, singular coefficients are neglected and the result can be represented by term variables, i.e. by a minimum quantity of different individual coefficients. The classes derived from a counter and from a class decoding gate array are compared with the pattern representing the term variables until the first congruent class is found. The associated class code is forwarded for further processing.
Abstract: A method of aligning two optical fiber ends so that they abut at their frontal faces and light that is fed into one of the two optical fibers is coupled over into the other optical fiber with the least amount of attenuation. A manipulator moves the optical fiber end it holds step-wise in the direction of its longitudinal axis (z) toward the other fiber end and after each step the manipulator is displaced transversely. The change in the coupled-over light power (P) is recorded as a function of transverse displacement and the displacement of the manipulator in the longitudinal direction is stopped as soon as a position (z.sub.0) is reached in which transverse displacement of the manipulator no longer produces a change in the coupled-over lightpower (P).
Abstract: In a high power, high-frequency junction circulator which includes a cooled ferrite structure disposed in a microwave junction zone where it is subjected to a static magnetic field, the ferrite structure is composed of a plurality of stacked ferrite balls. A coolant flows around the balls to carry away heat.
Abstract: A circuit including a digital filter bank for effecting conversion between a frequency multiplex signal having a sampling rate f.sub.A and L product sums corresponding to the sampled values of the frequency multiplex signal, the pulse response of the filter bank being of finite length, and a discrete Fourier transformation device for effecting conversion between the product sums and L individual complex signals. The sampling rate is reduced by the factor M.ltoreq.L in the transformation device so that only every M.sup.th value of the product sums is processed therein. In the filter bank, the frequency multiplex signal is a complex signal; the real portion and the imaginary portion of this signal are delayed in respective delay member chains associated with partial sequences of individual signal values which are sampled at a rate of f.sub.A /M.
Abstract: To correct temperature caused changes in symmetry and gain in a voltage controlled amplifier including a logarithm circuit and an antilog circuit, an auxiliary voltage proportional to the absolute temperature is provided to control the antilog circuit; this auxiliary voltage is also contained as a factor in a voltage which controls both the logarithm and the antilog circuits.
Abstract: A nonrecursive digital filter, particularly for filtering signals wherein identical values frequently occur in succession. The problem of making such a filter fully integratable at low expense is solved in that the time of a change in signal state with respect to a reference point in time is stored, with these points in time being utilized to address a further memory in which the system specific step response of the filter is stored. These step responses are weighted in a computer with the amplitude associated with each change in signal state, and are accumulated with the proper sign so that the accumulated output signal of the computer represents the desired filtered signal.
Abstract: A device for stripping the insulation from cables, including a guide block having a passage for receiving a cable and a knife bore extending transverse to, and communicating with, the passage, a knife assembly disposed in the knife bore and including a knife blade for cutting the cable insulation and a spring for urging the blade into the passage, and a handle for lifting and rotating the knife blade, associated with a lever mechanism pivotally mounted on the handle and pivotal relative to the handle in a manner to produce a lifting force which moves the knife blade in opposition to the force produced by the spring.
October 15, 1986
Date of Patent:
October 18, 1988
ANT Nachrichtentechnik GmbH, Wezag GmbH
Abstract: A microwave filter composed of a plurality of cylindrical cavity resonators each having a side wall extending parallel to the direction of wave propagation in the resonator, wherein the cavity resonators are disposed with their side walls in contact with one another in a compact cylinder pack arrangement so that the side wall of each cavity resonator is in contact with the side wall of the maximum number of other mutually adjacent resonators, and coupling structures connecting resonators whose side walls are in contact, via the contacting side walls, for coupling electromagnetic energy between the resonators.
Abstract: A motion compensating field interpolation method which allows the interpolation of several fields between every two transmitted fields of a digital television sequence. Using the model of translatorily displaced objects, a hierarchically structured displacement estimator is applied to cope with relatively large displacements. It provides a displacement vector with integer components for each picture element of the fields to be interpolated. A change detector is used to assure zero displacement vectors in unchanged areas. A two-coefficient spatio-temporal filter interpolates each picture element of the fields to be interpolated.
March 6, 1987
Date of Patent:
September 13, 1988
ANT Nachrichtentechnik GmbH
Matthias Bierling, Robert Thoma, Hans-Georg Musmann
Abstract: A junction circulator for high power, high-frequency use employs cooled ferrite material disposed in the microwave junction zone where it is exposed to a static magnetic field. The cooled ferrite material is provided by a plurality of small ferrite particles which are suspended in a liquid coolant.
October 2, 1987
Date of Patent:
September 13, 1988
ANT Nachrichtentechnik GmbH
Gunter Morz, Wolfgang Weiser, Sigmund Lenz, Erich Pivit
Abstract: Circuit device including: a waveguide for transmitting electromagnetic waves with an electric field extending in a selected direction; a diode mounted in the waveguide; a coaxial line connected for supplying a DC voltage to the diode; and a planar line for supplying at least one high frequency signal, the planar line extending perpendicular to the direction of the electric field and projecting into the waveguide, and the line being disposed at a distance from the diode for establishing a capacitive coupling with the diode.
Abstract: A method for producing antenna follow-up signals in which a sum signal and a difference signal are derived from a received beacon signal and an amplitude modulated signal is produced by superposition from these two signals. The amplitude modulated signal is converted into another frequency by means of a mixer which receives both the amplitude modulated signal and a mixing signal. The converted amplitude modulated signal is fed to an amplitude detector via a narrowband bandpass filter which permits only the signal frequency to pass. A voltage controlled oscillator is cyclically switched to produce a mixing signal which is fed to the mixer and which cyclically changes its frequency between two frequencies for the duration of each phase state of the difference signal. The converted signal at the output of the mixer changes its frequency between two further frequencies in response to the change of frequency of the mixing signal.
Abstract: An amplifier for ground symmetrical signals includes a compressor at the input and an expander at the output, with the slope of at least one of its expansion or compression characteristics being adjustable for at least one half-wave polarity with the aid of an adjustment voltage. In order to reduce second order distortions at the amplifier output, a circuit is provided for determining the arithmetic mean value of the voltage across the amplifier output. A control value is produced from the determined mean value and the slope of the expansion or compression characteristic is regulated with this control value in the opposite direction so that the distortions are reduced.
Abstract: A method and circuit for decoding binary signals processed according to an error correcting convolution code, in which the path metrics are transformed from the arithmetic into the logic range of operation. The path metric having the extreme value is subtracted from all other path metrics. All possible binary signal states occurring at the encoder are simulated in real time and are utilized to address hypothetical source data channels. From such a hypothetical source data channel fed by path decision bits, a buffer memory is actualized as well as the simulated binary signal states at the encoder. The output of decoded data from a buffer memory is effected in accordance with their addresses, namely for the extreme value of the path metric. For branching in the trellis diagram, the buffer memories whose associated trellis paths did not survive are overwritten.
Abstract: An arrangement for coupling waveguide modes between two waveguides via a semiconductor element. The two waveguides each have a short-circuiting end wall and a common side wall constituting a common partition wall between the waveguides so that the two waveguides extend parallel to, and overlap one another at least over a partial length where they are separated from one another by the common side wall. The common partition wall is provided with a coupling aperture and the semiconductor element is inserted into the coupling aperture between the two waveguides and is in ground contact with the common partition wall. The semiconductor element has two connectng arms, one connecting arm extending as a coupling probe into one of the waveguides and the other connecting arm extending as a coupling probe into the other waveguide.
Abstract: A microwave filter composed of at least two cavity resonators disposed adjacent one another, and a coupling aperture disposed between the resonators for coupling microwave energy between the resonators, one of the cavity resonators being operative to propagate microwave energy having a TE mode and the other of the cavity resonators being operative to propagate microwave energy having a TM mode, wherein the coupling aperture is constructed for coupling the TE mode in the one cavity resonator with the TM mode in the other cavity resonator.
Abstract: An arrangement for the equalization of attenuation and time delay in a microwave filter utilizing waveguide technology. An equalizer composed of a multi-circuit cavity resonator is coupled via a first coupling aperture to a waveguide which is connected to the filter. The resonator includes at least two individual waveguide sections coupled to each other via a second coupling aperture. The coupling apertures are dimensioned so that the resonator is critically coupled with respect to time delay characteristics. The resonator includes a power-absorbing tuning device for tuning all of the waveguide sections to substantially the same quality factor. The second coupling aperture presents a stepped cross section defining a first area and a second area having a larger cross section than the first area. The resonator further includes at least two screws arranged symmetrically with respect to the longitudinal axis of the resonator and protruding laterally into the second area of the second coupling aperture.
Abstract: A circuit arrangement for coupling alternating voltage signals having frequencies within the audio frequency range between a low noise audio frequency source and a zero ohm amplifier, wherein the audio frequency source has a known source impedance. The circuit arrangement includes an output connected to the zero ohm amplifier and a highly resistant input for receiving the alternating voltage signals from the audio frequency source. The input is more resistant by at least one power of ten than the source impedance of the audio frequency source and the arrangement has a voltage amplification factor which is so low that no overshooting of the output signal will happen at the maximum occcurring voltage of the signals received at its input. The output of the arrangement is configured as a short-circuit resistant alternating current source which furnishes a maximum effective current of at least 10 mA.
Abstract: A method and apparatus for the transmission of time discrete signals between source and sink systems wherein a first signal x(n) is generated by the source system at a first sampling rate f.sub.i and a second time discrete signal y(m) is generated by a sink system at a second sampling rate f.sub.0. The method is carried out by cyclically distributing the first time discrete signal to each of L filter groups at the first sampling rate f.sub.i. Each of the L filter groups comprises M filter elements which have their inputs connected to a common terminal and have the transfer function H.sub.l,m (z.sup.LM, where L and M are integers, l is an integer 0, 1 . . . L-1 corresponding to the filter group in which the filter element is located and m is an integer 0, 1 . . . M-1 corresponding to the location of the filter element in its associated filter group. The first time discrete signal is filtered in each of the filter elements at a processing rate f.sub.i /L and the filtered signals stored in the filter elements.