ULF Multi‐Key Tunable Magnetoelectric Antenna Array with Enhanced Communication Data Rate

Abstract Low‐frequency electromagnetic (EM) waves are essential in underwater, deep‐earth, and other communication environments due to their minimal attenuation. The magnetoelectric (ME) antenna, a novel mechanical antenna, provides a promising solution for low‐frequency EM wave communication, overcoming the limitations of conventional designs in terms of size and efficiency. To address the low transmission rate in low‐frequency EM wave communication, this paper proposes a multi‐key tunable antenna array based on an ME cantilever beam design. Each antenna array element consists of Metglas/0.7Pb(Mg 1/3 Nb 2/3 )O3–0.3PbTiO 3 (PMN‐PT) ME composite. Simulations identified a structure that significantly lowers the resonant frequency, allowing the ME antenna array to operate within the ultra‐low frequency (ULF, 300 Hz‐3000 Hz) band. Furthermore, the resonant frequency can be tuned over a range of 500 Hz, enabling multi‐frequency‐shift keying (MFSK) communication. Using quaternary FSK (4FSK) modulation, a 40 baud color image transmission is successfully demonstrated in a 5 S m −1 saline environment. Compared to binary FSK (2FSK) at the same baud rate, the transmission speed is increased by 100%. This approach achieves both low attenuation and high transmission rates, offering a promising new direction for ocean communications.