Abstract: A mechanical switching unit for selectively moving a functional component from a first position to a second position has an input element, an output element, a first holding point and a second holding point. The input element is set in motion by a drive. The output element is in engagement with the input element and is set in motion by the input element. The input element moves the output element from the first position to the second position, and vice versa. In the process, the functional component is moved from the first position to the second position, and vice versa. The first holding point exerts a first holding force on the functional component in the first position. The second holding point exerts a second holding force on the functional component in the second position.

Abstract: A radio-frequency assembly is described which can be used in communication satellites, for example. The radio-frequency assembly contains a signal source in the form of a semiconductor amplifier output, an impedance matching filter, and a radio-frequency waveguide. The impedance matching filter is connected to the semiconductor amplifier output on the input side and to the radio-frequency waveguide on the output side. The impedance matching filter has a different impedance value on the input side from that on the output side and is matched to the semiconductor amplifier output on the input side and matched to the radio-frequency waveguide on the output side. Consequently, a separate matching circuit between semiconductor amplifier output and radio-frequency waveguide is no longer necessary.

Abstract: A waveguide arrangement contains a first ridged waveguide and a second waveguide. The first ridged waveguide contains a first casing with a first cavity and a first ridge extending in the first cavity in the longitudinal direction. The first ridge is conductively connected to a wall of the first casing. The second waveguide contains a second casing with a second cavity. The first ridged waveguide overlaps the second waveguide in the longitudinal direction of the waveguide arrangement in a connecting section to produce a capacitive coupling between the first ridge and the second waveguide.

Abstract: A control device for a frequency generator of an ion thruster is described. The control device permits the detection of zero-crossings in a current and/or voltage characteristic during specific time intervals only, which detection is inhibited during other time intervals. Any incorrect switching performance of the control device associated with erroneously detected zero-crossings is prevented accordingly. A low-pass filter filters harmonics out of the detected current and/or voltage characteristics. A time-delay element offsets stray delays in the detection of zero-crossings. Additionally, plasma energy protective apparatuses are described, which attenuate the impact of any power flashover from a thruster unit to a power supply unit of an ion thruster.

Abstract: An amplifier arrangement has a plurality of function strings, which are required for nominal operation. In addition, the amplifier arrangement has a redundancy circuit and a redundant function string including a redundant converter and a redundant amplifier. If a function string is faulty, the redundancy circuit supplies the input signals of the faulty function string to the redundant function string. In addition, a high-frequency system with an inner housing and an outer housing is described, wherein an air gap separates the inner housing and the outer housing from one another so that high-frequency signals can be transmitted via the air gap between the inner housing and the outer housing.

Abstract: An optical communication unit for sending and receiving optical communication signals is described. The optical communication unit includes an optical unit, an elevation drive and an azimuth drive. The optical unit emits and/or receives optical communication signals. The elevation drive is coupled with the optical unit by way of an elevation bearing and swivels the optical unit about an elevation axis. The azimuth drive is coupled with the optical unit and the elevation drive and turns the optical unit together with the elevation drive about an azimuth axis. The elevation axis is arranged eccentrically with respect to the azimuth axis, so that the elevation axis is offset with respect to the azimuth axis by a lateral offset. This allows the optical unit to be swiveled to alongside the azimuth drive, so that a swiveling range of the optical unit is increased.

Abstract: A hollow conductor has a first flange, a second flange, a flexible hollow conductor section, and a first fastening unit. The flexible hollow conductor section is electrically connected both to the first flange and to the second flange in such a way that a radio-frequency signal (RF signal) can be transmitted from the first flange to the second flange or vice versa via the flexible hollow conductor section. The flexible hollow conductor section has a surface, and a first depression is arranged in the surface. The first fastening unit is connected to the first flange. The first fastening unit rests against the surface of the flexible hollow conductor section in a first overlap region in a longitudinal direction of the flexible hollow conductor section and engages in the first depression of the flexible hollow conductor section and thereby fixes the flexible hollow conductor section with respect to the first flange.

Abstract: An amplifier arrangement has a plurality of function strings, which are required for nominal operation. In addition, the amplifier arrangement has a redundancy circuit and a redundant function string including a redundant converter and a redundant amplifier. If a function string is faulty, the redundancy circuit supplies the input signals of the faulty function string to the redundant function string. In addition, a high-frequency system with an inner housing and an outer housing is described, wherein an air gap separates the inner housing and the outer housing from one another so that high-frequency signals can be transmitted via the air gap between the inner housing and the outer housing.

Abstract: A communication unit and a method for calibrating the alignment of a communication unit in a mobile carrier platform are described. The method incudes the following steps: determining an initial alignment of the communication unit with the moon on the basis of a position and bearing of the mobile carrier platform; moving the communication unit so that it adopts the initial alignment; tracing a search pattern with the communication unit starting from the initial alignment until a detection unit detects the moon; determining a real alignment of the communication unit when the detection unit detects the moon; determining a difference between the initial alignment and the real alignment of the communication unit; using this difference when performing a target alignment with the communication unit.

Abstract: A modulator unit for modulating the phase of a polarization component of an optical signal contains a polarizing beam splitter and a phase shifter. The beam splitter splits an input signal into a first and a second polarization components having different polarization directions and sends the components in opposite directions via an optical ring containing the phase shifter. A polarization rotator is arranged in the optical ring, which changes the polarization direction of passing optical signals, so that the polarization components arriving at the phase shifter are polarized in the same direction. The phase shifter changes the polarization directions of the incoming optical signals such that they are polarized orthogonally to one another in the phase shifter. One polarization component is modulated. When the optical signals leave the phase shifter, their polarization direction is brought back to the original polarization direction.

Abstract: A modulator unit for modulating the polarization of an optical signal includes a light source, a polarization-dependent phase modulator, and a reflector. The light source outputs an optical signal and emits it as the input signal directed at the phase modulator. The optical signal contains a first and a second polarization components having a first and a second polarization directions, respectively. The phase modulator modulates a first phase of the first polarization component in the first polarization direction and passes on the modulated input signal to the reflector. The reflector retroreflects the received optical signal towards the phase modulator and changes its polarization by 90°. The phase modulator modulates a second phase of the second polarization component of the retroreflected optical signal in the first polarization direction. The modulator unit outputs the modulated optical signal as the polarization-modulated output signal.

Abstract: A filter arrangement for high frequency signals, HF signals, is described. The filter arrangement includes a housing in which there is a cavity that extends in the longitudinal direction of the housing. The waffle-iron arrangement is arranged in the cavity and includes a carrier plate having a plurality of recesses, wherein there is an electrically conductive material arranged in at least some of the recesses, wherein the electrically conductive material in each case forms a pin in the at least some recesses. This structure makes it possible to provide a filter arrangement for very high frequencies, because the structure allows the carrier plate and the pins arranged therein to be provided with very small geometrical dimensions.

Abstract: A method for producing a hollow conductor is specified. The hollow conductor has a first hollow-conductor section and a connecting section. The first hollow-conductor section contains a non-weldable aluminium alloy and the connecting section contains a weldable aluminium alloy. The method includes the step of: connecting the first hollow-conductor section to the connecting section by a laser-welding method.

Abstract: A radio-frequency assembly is described which can be used in communication satellites, for example. The radio-frequency assembly contains a signal source in the form of a semiconductor amplifier output, an impedance matching filter, and a radio-frequency waveguide. The impedance matching filter is connected to the semiconductor amplifier output on the input side and to the radio-frequency waveguide on the output side. The impedance matching filter has a different impedance value on the input side from that on the output side and is matched to the semiconductor amplifier output on the input side and matched to the radio-frequency waveguide on the output side. Consequently, a separate matching circuit between semiconductor amplifier output and radio-frequency waveguide is no longer necessary.

Abstract: A waveguide arrangement contains a first ridged waveguide and a second waveguide. The first ridged waveguide contains a first casing with a first cavity and a first ridge extending in the first cavity in the longitudinal direction. The first ridge is conductively connected to a wall of the first casing. The second waveguide contains a second casing with a second cavity. The first ridged waveguide overlaps the second waveguide in the longitudinal direction of the waveguide arrangement in a connecting section to produce a capacitive coupling between the first ridge and the second waveguide.

Abstract: An optical communication unit for sending and receiving optical communication signals is described. The optical communication unit includes an optical unit, an elevation drive and an azimuth drive. The optical unit emits and/or receives optical communication signals. The elevation drive is coupled with the optical unit by way of an elevation bearing and swivels the optical unit about an elevation axis. The azimuth drive is coupled with the optical unit and the elevation drive and turns the optical unit together with the elevation drive about an azimuth axis. The elevation axis is arranged eccentrically with respect to the azimuth axis, so that the elevation axis is offset with respect to the azimuth axis by a lateral offset. This allows the optical unit to be swiveled to alongside the azimuth drive, so that a swiveling range of the optical unit is increased.

Abstract: An amplifier arrangement has a plurality of function strings, which are required for nominal operation. In addition, the amplifier arrangement has a redundancy circuit and a redundant function string including a redundant converter and a redundant amplifier. If a function string is faulty, the redundancy circuit supplies the input signals of the faulty function string to the redundant function string. In addition, a high-frequency system with an inner housing and an outer housing is described, wherein an air gap separates the inner housing and the outer housing from one another so that high-frequency signals can be transmitted via the air gap between the inner housing and the outer housing.

Abstract: A reception unit for use in a data link and a method for error correction on a reception word in a data link are specified. A low-density parity-check code, LDPC code, is used to iteratively adapt the reception word by virtue of bit node messages and check node messages being exchanged. The check node messages that are transmitted to the bit nodes are quantized in three levels and adopt the values ?1, 0 or +1. The method may thus be implemented with low computational expenditure.

Abstract: A high-frequency module can be used in communication satellites. The high-frequency module contains an electronic unit and a housing. The housing at least partially encloses the electronic unit, and the electronic unit is arranged at least partially in an interior space of the housing. An internal connector is arranged on the housing, which is coupled to the electronic unit such that electrical signals can be transmitted between the electronic unit and the internal connector. The internal connector is constructed integrally with at least a part of the housing. This allows a thermo-mechanical stress on the electronic unit to be reduced.

Abstract: A device for a sending and receiving unit of a communication arrangement is provided. The device includes: a first passage for electromagnetic waves and a second passage for electromagnetic waves; a partially transparent surface which is transparent for electromagnetic waves of a first wave length range and which is reflective for electromagnetic waves of a second wave length range, wherein the second wave length range differs from the first wave length range; and a first retroreflective surface which is retroreflective for electromagnetic waves of the first wave length range. A direction of reflection of the electromagnetic waves of the first wave length range differs from a direction of reflection of the electromagnetic waves of the second wave length range if the electromagnetic waves of the first wave length range as well as the electromagnetic waves of the second wave length range are incoming through the same passage.