An arrangement for electronically steering a radiation lobe of an antenna. Radiators of the antenna are located in a row and two radiators, which are equidistant from a midpoint of the row, form a radiator pair. To steer the radiation lobe, each pair is associated with a reflection-type phase shifter, implemented by a shared transmission line and reflection point, which can be moved. Phase changes take place by moving the reflection point along the transmission line using one movable or several fixed reflection circuits. The phase adjusting for all radiator pairs in a row is implemented simultaneously by a common control circuit. In the former case the reflection circuits of the different transmission lines are slides attached to one and the same movable arm. In the latter case one of the reflection circuits of each transmission line is activated at a time.