volume | PIER Journals

Abstract

Underwater electromagnetic communication is severely limited by the high permittivity and conductivity of water, which cause strong attenuation at higher frequencies. To overcome this challenge, a compact dual-polarized hexagonal loop antenna is proposed and experimentally validated for low-frequency underwater communication at 40-45 MHz. The antenna, fabricated on FR-4 and sealed with epoxy resin, eliminates bulky waterproof housings while ensuring stable impedance performance with a measured return loss better than -10 dB. Experiments conducted in freshwater confirm the effectiveness of polarization diversity, achieving an average received-power improvement of 4.59 dB under maximal-ratio combining. These results demonstrate, for the first time, the feasibility of a practical dual-polarized hexagonal loop design for robust, low-frequency underwater communication systems and future MIMO-like implementations.

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Dr. Joko Suryana

Mr. Ali Rhomadoni

Dr. Ahmad Izzuddin