Frequency Response and Eddy Current Power Loss in Magneto-Mechanical Transmitters

Magneto-Mechanical transmitters offer a compact and low-power solution for the generation of ultralow-frequency (ULF) magnetic signals for through-ground and through-seawater communications. Resonant arrays of smaller magneto-mechanical transmitters are particularly interesting in this context as the physical scaling laws allow for the increase of operating frequency and reduce the power requirements for ULF signal generation. In this work, we introduce a generalized model for accurate prediction of frequency and mode shape in generalized magneto-mechanical resonator arrays (MMRAs) that account for near-field magnetic interactions as well as magnetically induced nonlinearity. Using experiments, we demonstrate that our predictive capability is significantly improved compared against simplified dipole approximations. We additionally model the eddy current losses internal to the array and find that they are in agreement with experimental observations.

Automated summary

Magneto-Mechanical transmitters are a compact and low-power solution for generating ultralow-frequency magnetic signals for through-ground and through-seawater communications. Resonant arrays of smaller magneto-mechanical transmitters can increase operating frequency and reduce power requirements. This study introduces a generalized model that accurately predicts frequency and mode shape in magneto-mechanical resonator arrays, considering near-field magnetic interactions and magnetically induced nonlinearity. Experimental results show improved predictive capability compared to simplified dipole approximations, and the modeled eddy current losses align with experimental observations.