A magnetic resonance system has a transmission antenna that excited magnetic resonance signals in an examination subject arranged in an examination volume, a radio-frequency source that is stationaryor mobile in the examination volume or in its surroundings and by means of which an electrical field oscillating at the excitation frequency can be generated. A barrier is arranged between the radio-frequency source and the examination volume-the barrier formed of a number of individual resonators that are respectively inherently resonant at the excitation frequency. The examination volume is shielded by the barrier from the electrical field generated by the radio-frequency source. Each individual resonator has two capacitor surfaces of which one faces toward the radio-frequency source and theother faces the examination volume, and they are connected with one another in an electrically-conductive manner via a coil. The capacitor surface facing toward the radio-frequency'source and/or thecapacitor surface facing toward the examination volume are not directly connected with one another in an electrically-conductive manner.