A radar device includes a RF signal source, two or more antenna interface units, a feed network, and a control unit. The RF signal source is arranged to provide a RF signal; each of the antenna interface units includes an antenna port and one of the following: an amplifier and a mixer; the feed network includes two or more buffers, each buffer has an active and an inactive state; the control unit is arranged to generate or receive a selection signal which specifies none, one, or more of the antenna interface units as active antenna interface units and the remaining antenna interface units as inactive antenna interface units; the control unit is arranged to activate and deactivate the buffers in dependence on the selection signal so as to feed the RF signal to the none, one, or more active antenna interface units and not to the inactive antenna interface units.