Radar sensors are used primarily as signal transducers for controlling automatic doors and gates. They detect the movement of persons and/or industrial trucks and, at the same time, are insensitive to soiling. Objects can be detected depending on their movement direction in order to optimize the opening cycles of the gates. In doing so, it is possible to mask out people so that the sensor responds only when vehicles approach. Furthermore, it is possible to eliminate interference caused by moving objects within the detection range of the sensor. Systems that are also equipped with presence detection monitor the area in front of a gate in order to prevent the gate leaf from coming into contact with vehicles or objects.