Evaluation of Applied Axial Field Modulation Technique on ME Sensor Input Equivalent Magnetic Noise Rejection

By using nonlinearity effects in magnetostrictive - piezoelectric laminated sensors, modulation techniques can transfer low-frequency signals to higher frequencies. Theory predicts that the transfer ability depends mainly on the amplitude of the carrier signal and the sensor nonlinearity. This was confirmed by our experiments. We present the first analysis on a ME noise model associated to a modulation technique. Furthermore, the overall equivalent magnetic noise was analyzed, and shown to be dominated only by the signal transfer ability and the output electrical noise level appearing around the carrier frequency.