Effect of the Permittivity and Conductivity of the Buffer Material on Axial-Mode Helical Antenna Performance for Underwater Application

Wireless underwater communication is designed to monitor and transmit data from underwater environments without physical cables or direct connections to the surface. It is very useful for surveillance purposes, especially environmental monitoring, underwater infrastructure protection, underwater research, and maritime security. In certain shallow water or near-surface situations, wireless underwater communication can be facilitated via radio frequency technology. From previous research, most of the underwater antennas produced an omnidirectional radiation pattern with a poor antenna gain. An underwater network would require directional antennas with high gain due to the losses from the water. This research proposes a high-gain axial mode helical antenna that operates with distilled water as a buffer medium for freshwater applications. The lambda in water is used during the calculation of the antenna parameters, which results in a smaller antenna size. To figure out the best condition for the proposed antenna to perform, a few antenna arrangement conditions were examined. The result reveals that the antenna that was placed in a PET container filled with distilled water showed the best performance in terms of S
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, radiation pattern surface current.