MR antenna system MR apparatus so and operating method thereof

An MR antenna system (AS1) has at least a high frequency source (G1-G4) for emitting a radio frequency signal (HF1-HF4) and a plurality of the at least one high-frequency source can be fed antenna elements (A1-A4), which via a passive network (BM) with the at least one high-frequency source (G1-G4) are connected. The MR apparatus (MRI) can adjust to the network (BM) to be fed high-frequency signals so that they are selectively distributed over the network outputs. The method is used (AS1) for operating an MR antenna system, wherein a plurality of different relative phase and / or signal level high frequency signals are fed to respective network inputs of a Butler matrix, the output is connected with antenna elements and the phase and / or signal level may be varied in time, a distribution of high-frequency signals to vary the antenna elements in time. The invention is applicable to, for example, MR devices or MR system with a sequential excitation or activation of the MR antenna elements. The invention is particularly applicable to MR devices that produce ultra high B0 fields from seven Tesla, especially for a very high resolution and / or fast imaging in magnetic resonance tomography.