The present invention relates to a device for adjusting the beam direction of a beam radiated from a stationary array of antenna elements. Antenna element feed points are coupled to a common source via a feed line structure having a source connection and feed connection terminals to be connected to the antenna element feed points, the feed line structure being at a distance from and in parallel to a fixed ground plane. A movable element is located adjacent to the feed line structure to change the signal phase of signal components being transferred between the source connection and the respective feed connection terminals. The movable element is movable for effecting a phase shift of the signal components to adjust the beam direction. The device is provided with a detection arrangement for detecting the absolute position of the movable element.