Orthogonal fluxgate sensor for measuring an external magnetic field Hext, comprising a conductor for carrying an excitation current lexc, a ferromagnetic material adapted to saturate in the presence of a magnetic field generated by the excitation current, and at least one pick-up coil adapted to detect variations in the magnetic field in the vicinity of the magnetic material. The excitation conductor comprises a substantially linear elongated portion of conductive, non-magnetic material, forming an excitation rod (6). The magnetic material surrounds the excitation rod in the form of a cladding (8).