Asymmetric self-biased LF magnetoelectric antenna system for underwater temperature sensing and communication

To meet the dual requirements of miniaturizing low-frequency (LF) communication and sensing systems in complex underwater environments, this work proposes an asymmetric self-biased LF Magnetoelectric (ME) antenna system based on a magnetic gradient structure for integrated underwater temperature sensing and communication. Experimental results demonstrate that the self-biased ME antenna overcomes the limitations imposed by the traditional Chu-Harrington limit for electrically small antennas. Operating at 99.4 kHz in simulated seawater, the system achieved a temperature sensitivity of 0.17 μV/°C over 30 cm under a 40 V_PP drive, demonstrating stable performance from -1.4°C to 29.6°C with reliable data transmission and low bit error rates. This approach is expected to provide new insights for the development of the underwater Internet of Things and holds significant potential for advancing the exploration and utilization of marine resources.