Rejecting a disturbing signal e.g. a radio communications jamming electronic countermeasures signal

摘要

The device 1 is connected to two antennas A1 and A2 of an antenna system and produces an output signal comprising essentially the useful signal component, the useful signal and the disturbing signal being statistically independent of each other and the useful signal being a signal intermittently transmitted during active phases preceded by inactive phases. The device comprises weighting means for weighting, in phase and in amplitude, respective signals simultaneously picked up by the two antennas A1 and A2 so as to conform the overall radiation pattern of the antenna system to exhibit an attenuation in the direction of the source from which the disturbing signal comes, a first feedback control loop for controlling the weighting means, allowing to control them in a power inversion mode, a second feedback control loop for controlling the weighting means, allowing to control them in a source separation mode, means responsive to the system output level for determining inactive and active phases of the transmitted useful signal, and mode switching means controlled thereby so as to select the power inversion mode upon the determination of an inactive phase, then to select the source separation mode upon detection of a subsequent active phase.