Sensitivity Improvement of TbDyFe Thin-Film Coated Saw-Based Current Sensor

In this paper, a novel surface acoustic wave current sensor combining SAW technology and magnetostrictive material is proposed. The typical structure of the sensor is a surface acoustic wave device surface sputtered hysteresis film based on planar lithography. The magnetic sensitive materials with high magnetostriction coefficient are a key factor. In this paper, the TbDyFe giant magnetostrictive film with better performance is used to induce the magnetostrictive strain by applying a magnetic field induced by current, which causes the SAW propagation speed to change. The applied current is evaluated using the differential oscillation frequency offset of the differential delay line oscillating loop. Current experiments show that the current sensor proposed in this paper has high sensitivity and good linearity.