Acoustically Actuated Compact Magnetoelectric Antenna for Low-Frequency Underwater Communication

Magnetoelectric (ME) antenna has proven to be an effective solution for antenna miniaturization. In recent years, the ME antennas adopted for communication in atmospheric and water environment has been verified. The ocean accounts for about 71% of the Earth's surface area, which can be used for environmental monitoring, weather forecasting, earthquake forewarning, and marine biological research. The exploration and development of ocean resources depend on underwater communication, so it is promising to study the communication of low-frequency (LF) ME antennas in seawater environments with lossy media. In this work, a laminated sandwich-structured Terfenol-D/lead zirconate titanate (PZT)/Terfenol-D based on an acoustically actuated compact LF ME antenna with 91.8 kHz frequency is proposed to realize bidirectional communication in saline environment with the conductivity of 5 S/m. Experimental results show that the proposed ME antenna achieves the best performance under the action of a 300 Oe dc-biased magnetic field, and the near-field radiation characteristics in the yo z plane and the xo z plane are equivalent to those of the magnetic dipole antenna. In a saltwater environment, the proposed ME antenna is capable of transmitting and receiving electromagnetic (EM) waves, and an effective communication distance of 30 cm is realized by amplitude shift keying (ASK) modulation. This research shed light on the miniaturized LF ME antenna that can realize bidirectional wireless communication in lossy media (such as seawater environment), which is expected to provide technological support of communication for ocean exploration.