Abstract: An arrangement is described for the equalization of a frequency signal, the arrangement including a channel filter and an equalizer connected downstream of the channel filter, for a satellite communication system in particular. The equalizer is an at least partially superconductive reflection equalizer.

Abstract: An electrically tunable planar filter has a filter element including a substrate having an upper side and a wave-guide arranged on the upper side of the substrate, at least one tuning element composed of at least one material selected from the group consisting of a ferroelectric material and an antiferroelectric material with adjustable voltage applied to the tuning element and thereby with an adjustable dielectric constant, the tuning element being arranged at the upper side of the substrate.

Abstract: In a cooling apparatus for a high-frequency receiver having an input circuit which carries signals that are not yet sufficiently amplified, the input circuit is thermally connected to a miniature cooler and is thermally insulated, including a cold output of the miniature cooler, from the environment. It is particularly favorable if the miniature cooler has no moving parts on the cooling end. The miniature receiver is preferably configured as a pulse tube cooler.

Abstract: A portion of the superconductor in a planar resonator made from that superconductor can be switched into the normally conducting state so that its effective lateral dimensions are changed. The special advantage of this planar resonator is that a switchable filter can be constructed very economically based on its planar resonator structure. Since no perturbing bodies are necessary in the field, the invention points the way to a switchable filter with reduced high frequency losses.

Abstract: The superconductor bandpass filter for electromagnetic signals includes a substrate (5); striplines (1) made of a type II superconductive material arranged on the substrate and a tuning device (2) for tuning the superconductor bandpass filter consisting of a device for changing a magnetic penetration depth .lambda.(T) of the striplines (1), so as to change the effective length, effective width and effective spacing of the striplines and thus to change the center frequency and/or the bandwidth. The device for changing the magnetic penetration depth .lambda.(T) of the striplines (1) advantageously includes a device for exerting a mechanical force or stress on the striplines and/or a device for varying a magnetic field applied to the striplines.

Abstract: The planar superconducting resonator includes a substrate (1), a symmetrically shaped stripline (2) applied to the substrate (1) in which two orthogonal electromagnetic modes are excitable and including a symmetry perturbation for coupling the two orthogonal electromagnetic modes, an additional stripline (5) arranged on the substrate in the vicinity of the symmetry perturbation, a Josephson junction (3) arranged between the symmetry perturbation and the additional stripline (5) and a device for generating and controlling a magnetic field at the Josephson junction (3) so that the degree of coupling between the two orthogonal electromagnetic modes is varied. The Josephson junction (3) is formed by a non-superconducting layer (4) arranged between the symmetry perturbation and the additional stripline (5).

Abstract: A planar filter is proposed in which a plurality of striplines arranged next to one another on a substrate are supplemented by an overcoupling stripline which couples to one another two striplines which are not immediately neighboring. The length of the overcoupling stripline is an integral multiple of a half wavelength of the center frequency of the filter.