Magnetic Field Distortion From Conductive Layers for High-Frequency Speed Sensor Applications

Abstract

In previous works, the known scalar approach for the vector potential was extended to determine the influences of eddy currents in metallic layers in a closed form, based on a connection between infinite integrals of Bessel functions and the complete elliptic integrals. While the original idea treats only thin layers with respect to the penetration depth, in this paper, the formalism is extended to the opposite limit of thick layers. It was shown that the developed formalism can be used as a framework to analyze and classify the development of eddy currents in speed sensor systems and even to advocate on chip layout. This extension to thick layers is of great interest in this context as it describes the regime where eddy currents strongly influence the sensor output signal.