Abstract A novel magnetic field sensor is presented in this paper. It combines the classical Fluxgate principle with the anisotropic magneto-resistance (AMR) effect exhibited by barber-pole biased AMR film-resistors. It is shown that such film-resistors can be used as Fluxgate magnetic cores, because they exhibit one high-resistivity state and one low-resistivity state depending on the film magnetization polarity. Periodical alteration of the magnetization polarity, forced by an excitation field, makes the film-resistivity become a rectangular function of time, whose duty-cycle is proportional to the measured ambient field intensity. The proposed design helps with the suppression of repeatability and time-drift errors that are common in AMR sensors; the excitation field enhances the spin-alignment along the easy-axis of the film-resistor. The design also provides excellent temperature stability. Moreover, it is shown how a single AMR film-resistor can be employed for simultaneous sensing of two field components (i.e. on a x – y plane); the first component modulates the duty-cycle of the rectangular function (Fluxgate principle) and the latter its amplitude (conventional AMR effect). A complete mathematical modeling of the proposed sensor is presented in this work. The theoretical results have been verified by the use of a Honeywell HMC1021 single-chip sensor. The calibration data fairly agrees with the theory.