The invention relates to an open MR system in which the magnetic RF field is to be adjusted at will in respect of field profile. This is achieved in accordance with the invention by providing an RF coil system for the transmission and/or reception of RF signals, which RF coil system includes two RF coil arrays which are arranged on opposite sides of the examination zone, each RF coil array including at least two RF coils which are decoupled from one another and are connected to a respective channel of a transmit/receive unit. The invention also relates to a corresponding planar RF coil array.