An Underwater Simultaneous Wireless Power and Analog–Digital Hybrid Signal Transfer System

An underwater simultaneous wireless power and analog–digital hybrid signal transfer system is proposed in this letter to meet the needs of analog and digital signal transmission in underwater sensor networks in seawater. The system transmits two digital signals and one analog signal through the same coil, meeting the practical needs of multiple signal transmissions, improving the communication rate, and retaining the precision and continuity of analog signals as well as the accuracy of digital signals. The system uses a coaxial coil coupling structure, with the outer ring for power transmission and the inner ring for signal transmission, featuring a simple and compact design. The experimental platform achieved a 400 W output power, 1 Mbps bidirectional digital signal transmission, and 20 kHz unidirectional analog signal transmission in seawater, with a transmission efficiency of 90.8%, verifying the feasibility of the proposed theory.