A Method for Precisely Calculating the Radiation Resistance of Loop Antennas in Seawater

ABSTRACT With the increasing demand for underwater communication, the study of electromagnetic (EM) wave propagation in complex marine environments, especially for unmanned platforms, is crucial. Loop antennas are widely used in underwater wireless communication for their simple structure and high efficiency. But the traditional spherical integration for calculating their radiation resistance is inaccurate due to seawater induced EM wave attenuation. This paper proposes a cylindrical surface integration based method, validated by simulations and offshore experiments, to calculate it more accurately, offering a reliable basis for underwater loop antenna and communication system design.