The magnetized structure that induces in a central area of interest a homogeneous magnetic field oriented along a longitudinal axis (z) of the structure comprises first and second magnetized rings (111, 121) disposed symmetrically relative to a plane (P) that is perpendicular to said longitudinal axis (z) and that contains said central area of interest, and one median annular magnetized structure (330) disposed between the first and second magnetized rings (111, 121) and also disposed symmetrically relative to the plane (P) of symmetry. The first magnetized ring (111) is magnetized radially relative to the longitudinal axis (z) with divergent magnetization, the second magnetized ring (121) is magnetized radially relative to the longitudinal axis (z) with convergent magnetization, and the median annular magnetized structure (330) is magnetized along the longitudinal axis (z). The median annular magnetized structure (330) is divided into at least two slices (331A, 331B, 332A, 332B) along the longitudinal axis (z) and the first and second magnetized rings (111, 121) and the various slices (331A, 331B, 332A, 332B) of the median magnetized structure (130) are each divided into identical components in the form of regularly distributed sectors.