a time - variable magnetic fields generator for a magnetic resonance apparatus has at least one gradient coil with conductors extending essentially in the region of a subject - receiving hollow opening of the magnetic resonance apparatus , and that is free of conductors in a middle axial region of the hollow opening , a first radio - frequency shield that encloses the conductors disposed on the one side of the middle region , a second radio - frequency shield that encloses the conductors disposed on the other side of the middle region , a radio - frequency antenna element that emits a radio - frequency field , disposed between the first and second radio - frequency shield in the middle region , a third radio - frequency shield proceeding radially , externally around the antenna element , such that the radio - frequency shields delimit a field return space within the generator and that is designed for a return of the radio - frequency field .