Thin film integrated AMR sensor for linear position measurements

A simple anisotropic magnetoresistive (AMR) sensor for linear positioning is designed as integrated bridge structure and implemented based on standard technology processes and rotation of the initial anisotropy axis after the patterning of the resistors. The behavior of the separate resistors is investigated by varying the intensity (0 +/- 5 kA/m) and direction (0 degrees, 45 degrees, 90 degrees in respect to the initial anisotropy axis) of the applied magnetic field. The experimental results are compared with data from simulation based on detailed analysis of the energy profile. Good agreement is obtained at assumed declination of151 between the anisotropy and geometrical axes of the resistors. It is shown that in spite of asymmetries and hysteresis observed at low magnetic fields at higher fields used usually for the purposes of automation the response of the structure is single-valued and stable. (C) 2008 Elsevier B.V. All rights reserved.