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 stationary or 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 the other 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 the capacitor surface facing toward the examination volume are not directly connected with one another in an electrically-conductive manner.