SIMULTANEOUS MEASUREMENT OF 2 DC MAGNETIC-FIELD COMPONENTS BY A SINGLE MAGNETORESISTOR

The method relies on a special excitation mode which causes uniform ro tation of magnetization in the plane of a barber-pole magnetoresistive sensor. It is interesting that the uniform rotation of the magnetizat ion is attained when the excitation field is not uniformly rotating. T he rotation of this field should rather be elliptically polarized. The two orthogonal components of an external in-plane measured dc field d isturb the uniform rotation of the magnetization in different instance s of time. This behavior of the magnetization enables simultaneous but still separate measurements of both external field components by dete ction of the time shifts between the corresponding zero-crossing point s of the sensor ac output and the zero-crossing points of the correspo nding orthogonal components of the excitation field. The experimental results confirm the applicability of the method. Possible applications are reviewed.