Improving the Spatial Resolution of Magneto Resistive Sensors via Deconvolution

State of the art GMR sensors are becoming more and more popular for a variety of applications, due to the progress in the area of magnetic field sensor technologies in the recent years. Especially in the area of non–destructive testing, the number of applications based on magnetic field sensors is steadily increasing. Up to now a major concern of these applications has been to improve the sensor’s sensitivity to be able to measure even minimal magnetic field variations. But an equally important characteristic, the sensor’s spatial resolution, is often neglected to discuss. In this paper the spatial resolution of two different GMR sensors are analyzed. The sensors are modeled as linear space–invariant systems. Based on the analytical solution for the magnetic field above a current carrying conductor and a corresponding measurement, the attainable spatial resolution is determined comparing two different deconvolution methods, an inverse and a Wiener filter. Finally, the determined sensor characteristics are used to improve the measurement accuracy significantly.