Magnetic-field sensor having a magnetic body with inhomogeneous magnetization

1. A magnetic-field sensor comprising:

a magnetic-field sensor arrangement; and

a magnetic body comprising an inhomogeneous magnetization, wherein the inhomogeneous magnetization comprises a first magnetization vector M at a first point within the magnetic body pointing in a different direction from a second magnetization vector M at a second point within the magnetic body, the magnetic body is a single piece, and the first and second magnetization vectors M are neither parallel nor antiparallel,

wherein the magnetic body comprises a recess facing the magnetic-field sensor arrangement and resulting in a non-convex cross-sectional area, and

wherein the magnetic body is fixedly arranged with respect to the magnetic-field sensor arrangement and forms a back-bias magnet for the magnetic-field sensor arrangement.

2. The magnetic-field sensor as claimed in claim 1 , wherein at least a portion of the cross-sectional area of the recess is polygonal.

3. The magnetic-field sensor as claimed in claim 2 , wherein the cross-sectional area of the recess is polygonal and comprises at least three vertices.

4. The magnetic-field sensor as claimed in claim 2 , wherein the cross-sectional area of the recess is mirror-symmetrical with respect to a symmetry line, wherein the magnetic-field sensor arrangement comprises a substrate comprising a main surface, and wherein the symmetry line intersects the main surface of the substrate at an angle of between 75° and 105° in relation to the main surface of the substrate.

5. The magnetic-field sensor as claimed in claim 1 , wherein the magnetic body comprises the inhomogeneous magnetization in at least 50% of a volume of the magnetic body.

6. The magnetic-field sensor as claimed in claim 1 , wherein the magnetic body comprises a radial magnetization directed at a central point.

7. The magnetic-field sensor as claimed in claim 6 , wherein the magnetic body comprises the radial magnetization in at least 50% of a volume of the magnetic body.

8. The magnetic-field sensor as claimed in claim 1 , wherein the magnetic body comprises an azimuthal magnetization which is tangentially directed with respect to a connecting line to a central point.

9. The magnetic-field sensor as claimed in claim 8 , wherein the magnetic body comprises the azimuthal magnetization in at least 50% of a volume of the magnetic body.

10. The magnetic-field sensor as claimed in claim 1 , wherein the magnetic body comprises a maximum deviation of a magnitude of the inhomogeneous magnetization of the magnetic body, the maximum deviation being smaller than or equal to 20% of a maximum magnitude of the inhomogeneous magnetization of the magnetic body.

11. The magnetic-field sensor as claimed in claim 1 , wherein the magnetic-field sensor arrangement comprises a first magnetic-field sensor element and a second magnetic-field sensor element, the first magnetic-field sensor element being arranged, with respect to the magnetic body, such that the first magnetic-field sensor element is exposed, with regard to a predetermined spatial direction, to a first magnetic flux density caused by the magnetic body and being within a first flux density range, and the second magnetic-field sensor element being arranged, with respect to the magnetic body, such that the second magnetic-field sensor element is exposed, with regard to the predetermined spatial direction, to a second magnetic flux density caused by the magnetic body and being within a second flux density range.

12. The magnetic-field sensor as claimed in claim 11 , wherein the first flux density range and the second flux density range enable operation of the first and second magnetic-field sensor elements outside a saturation range.

13. The magnetic-field sensor as claimed in claim 11 , wherein the first and second flux density ranges only comprise values smaller than or equal to 20 mT in magnitude.

14. The magnetic-field sensor as claimed in claim 11 , wherein the first and second magnetic-field sensor elements are magneto-resistive sensor elements.

15. The magnetic-field sensor as claimed in claim 11 , wherein the first and second magnetic-field sensor elements are arranged on a substrate, and wherein the predetermined spatial direction is parallel to a main surface of the substrate.

16. The magnetic-field sensor as claimed in claim 1 , wherein a vector component of the first magnetization vector M perpendicular to a sensor plane of the magnetic-field sensor arrangement has a same polarity of a vector component of the second magnetization vector M perpendicular to the sensor plane of the magnetic-field sensor arrangement.

17. A method of producing a magnetic-field sensor, the method comprising:

providing a magnetic body, the magnetic body comprising an inhomogeneous magnetization, wherein the inhomogeneous magnetization comprises a first magnetization vector M at a first point within the magnetic body pointing in a different direction from a second magnetization vector M at a second point within the magnetic body, first and second spatial areas existing with regard to the magnetic body, so that in the first spatial area, a first magnetic flux density caused by the magnetic body is within a first flux density range with regard to a predetermined spatial direction, and so that in the second spatial area, a second magnetic flux density is caused by the magnetic body with regard to the predetermined spatial direction, which is within a second flux density range, wherein the magnetic body comprises a non-convex cross-sectional area with respect to a cross-sectional plane running through the magnetic body, the magnetic body is a single piece, and the first and second magnetization vectors M are neither parallel nor antiparallel; and

arranging a magnetic-field sensor arrangement comprising first and second magnetic-field sensor elements, so that the first magnetic-field sensor element is arranged in the first spatial area, and the second magnetic-field sensor element is arranged in the second spatial area.

18. The method as claimed in claim 17 , wherein the magnetic body is a single piece, and the first and second magnetization vectors M are neither parallel nor antiparallel.

19. The method as claimed in claim 18 , wherein a vector component of the first magnetization vector M perpendicular to a sensor plane of the magnetic-field sensor arrangement has a same polarity of a vector component of the second magnetization vector M perpendicular to the sensor plane of the magnetic-field sensor arrangement.

20. A magnetic-field sensor comprising:

a magnetic-field sensor arrangement; and

a magnetic body, wherein the magnetic body comprises a radial magnetization which is directed to a central point, wherein the magnetic body is fixedly arranged with respect to the magnetic-field sensor arrangement and forms a back bias magnet for the magnetic-field sensor arrangement, wherein the magnetic body comprises an inhomogeneous magnetization, and wherein the inhomogeneous magnetization comprises a first magnetization vector M at a first point within the magnetic body pointing in a different direction from a second magnetization vector M at a second point within the magnetic body, the magnetic body is a single piece, and the first and second magnetization vectors M are neither parallel nor antiparallel.

21. The magnetic-field sensor as claimed in claim 20 , wherein the magnetic body comprises a recess on a side facing the magnetic-field sensor arrangement.

22. The magnetic-field sensor as claimed in claim 20 , wherein the magnetic body comprises a permanent-magnetic material having the radial magnetization.

23. The magnetic-field sensor as claimed in claim 20 , wherein the magnetic body comprises an annular or ellipsoidal section.

24. The magnetic-field sensor as claimed in claim 20 , wherein a vector component of the first magnetization vector M perpendicular to a sensor plane of the magnetic-field sensor arrangement has a same polarity of a vector component of the second magnetization vector M perpendicular to the sensor plane of the magnetic-field sensor arrangement.