A Bending-mode magnetoelectric antenna for ultra-low frequency wireless communication

Abstract In this study, a novel magnetoelectric (ME) antenna based on metglas-steel-piezo (MSP) is proposed to overcome attenuation in seawater. Many mechanical ME antennas use the length-stretching mode, and their radiation frequency is mostly concentrated at 10–20 kHz. The attenuation of electromagnetic (EM) fields in seawater is proportional to their frequency; therefore, their applications are limited. The converse magnetoelectric effect (CME) model of a bending-mode antenna was derived, and an equivalent circuit was developed based on the piezoelectric and magnetostrictive constitutive equations combined with the deflection equation. An MSP antenna with a volume of only 2.5 cm 3 was successfully manufactured. Utilizing the elasticity and stiffness characteristics of the MSP antenna, the bending mode dominates. The MSP antenna radiation intensity at 1.21 kHz reaches 13.5 nT rms at 1 m in air, with a Q value of 25. Adequate underwater communication of the 2ASK at 300 bps over a distance of 40 cm was achieved. This experiment verifies the excellent wireless communication ability of the bending ME antenna in the air-seawater cross-medium and provides an innovative direction for underwater communication technology.