New Method of Canceling Line Spectrum Noise in a Magnetic Shield by Using the Beat Phenomenon

Abstract

A new method is presented by which line spectrum noise can be cancelled, using the beat phenomenon. A reference magnetic field is superposed on the magnetic noise field in order to obtain a beat waveform, from which the phase and the amplitude of the magnetic noise can be identified. We applied the method to an open-structure, vertical cylindrical magnetic shield employing magnetic shaking, and evaluated the effect of canceling a line spectrum.