Magnetic field sensitivity of LC filter-type magnetoimpedance sensors

Abstract In this study, we discuss the basic concept and applicability of the LC high pass filter configuration for the magnetoimpedance sensors, and examine its performance with SPICE simulation and experiment using amorphous ribbon pattern as a sensor element. Special attention is given to the sensitivity of the filter configuration. The LC filter circuit shows the output-changing ratio per 1 Oe of 5% at 50 MHz. This value is larger in 2.5 times than the output-changing ratio expected in a conventional bridge circuit with constant current excitation.