A modified meander-line-coil EMAT design for signal amplitude enhancement

This work presents a modified meander-line-coil (MLC) electromagnetic acoustic transducer (EMAT) design with a new magnetic configuration for the enhancement of surface wave generation and detection. Numerical analysis is applied to characterize and optimize the new EMAT. It indicates that the new magnetic configuration can increase the peak flux density by a factor of ∼1.9, compared to the magnetic configuration used in the conventional MLC EMAT. As a result, both the generation efficiency and detection efficiency of the new EMAT are improved dramatically. Experiment has verified that the signal-to-noise ratio of the measurement system with using the new EMATs is increased by a factor of ∼5.3.