Abstract: A device is disclosed for converting a circularly polarized electromagnetic radiation into linearly polarized electromagnetic radiation. The device includes a depolarizer with depolarizing elements supported in a polarization mode converter for rotation between a vertical output and a horizontal output. A depolarization position for circularly polarized radiation exists between the horizontal output and the vertical output. The rotation direction of the depolarizer can be adjusted to selectively direct left-handed circularly polarized and right-handed circularly polarized radiation either to the vertical or the horizontal output.

Abstract: A tracking system for maintaining an alignment between a reflector antenna and a source of electromagnetic radiation, includes a reflector for reflecting electromagnetic radiation generated from a electromagnetic radiation source, a receiver, and a rotary sub-reflector which is positioned in front of the reflector for deflecting the radiation reflected by the reflector to the receiver and for generating triggering signals for measuring the strength of signals of the reflected radiation, whereby the sub-reflector is arranged at an inclination with respect to the reflector by an offset angle.

Abstract: A pair of filter units directs incoming signals from an antenna and outgoing signals to the antenna. One of the filter units blocks the outgoing signals and passes the incoming signals while the other of the filter units blocks the incoming signals and passes the outgoing signals.

Abstract: A coaxial antenna includes a vertical half-wave dipole with a lower section in form of a sleeve and an upper section in form of a first conductor bar, with the sleeve being dimensioned so as to resonate at a first frequency or first frequency range. A second conductor bar is operatively connected to the free end of the first conductor bar to define an assembly of first and second conductor bars which is dimensioned so as to resonate at a second frequency or second frequency range.