Design, Theoretical Modeling, and Experimental Evaluation of Low-Frequency Self-Biased Magnetoelectric Mechanical Antennas

This work presents the design, theoretical modeling, and experimental evaluation of low-frequency self-biased magnetoelectric mechanical (MEM) antennas. The thin magnet layer provides a self-biased magnetic field for achieving MEM antennas with a compact size and large radiation intensity. Bias magnetic field, nonlinear magnetostrictive (MS) effect, and the coupled longitudinal and bending modes are included in the theoretical model to accurately analyze self-biased MEM antennas. A novel self-biased MEM antenna with the bending cantilever mode is designed and optimized with the proposed theoretical model. A prototype of the proposed self-biased MEM antenna is fabricated. The self-biased MEM antenna exhibits an extremely compact size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8.2\times 2\times 0.39$ </tex-math></inline-formula> cm3. Measured results illustrate that the proposed self-biased MEM antenna operates in the ultralow-frequency (ULF) band of 356 Hz and is capable of producing 110-nT magnetic flux density for a transmission distance of 1 m. The measured and numerical results agree well with each other, which validates the accuracy and effectiveness of the proposed theoretical model. This study provides a theoretical framework for the modeling and development of self-biased MEM antennas and is attractive for applications requiring low-frequency long-distance communication.