A generator of time-variable magnetic fields of a magnetic resonance apparatus, said apparatus having an examination space for imaging of at least one area of an examination subject to be examined, incorporates the following features: the conductors of a gradient coil arrangement of the generator extent over an essentially disk-shaped area, the area includes at least one sub-area which is free from conductors of the gradient coil arrangement and within which are arranged conductors of a high-frequency antenna of the generator, and a field backflow space, which is available inter alia for fields of the high-frequency antenna, extends away from the examination space, starting from the sub-area.