Influence of temperature on signal attenuation at microwaves frequencies underwater

Abstract

New wireless applications are emerging subsea. Pinless Subsea Connectors (PSC) aim to transfer high-speed data over short distances. They present several advantages in comparison with previous technologies. However, its design presents several challenges that need to be addressed. For PSC based on electromagnetic signaling, one of the principal factors affecting system planning is signal attenuation. This work characterizes the impact of water temperature on signal attenuation in both freshwater and seawater. We present experimental data in the 0.5-3.5 GHz band at two typical values for the water temperature (5 and 22 °C). The study confirms that higher temperatures may help to enlarge system coverage in freshwater. However, the opposite effect is found in seawater. The obtained patterns of attenuation with the temperature are in agreement with the available empirical data. However, we also show that available data bases are not accurate enough for estimating signal attenuation for the presented working conditions.

Characterization of RF signals in Different Types of Water

“…represents angular frequency, represents dielectric permittivity at low frequency, ∞ is the dielectric permittivity at high frequency and represents the relaxation time [4].…”

“…Underwater radio propagation is also affected by temperature. In seawater, conductivity increases with temperature due to increased ionization, leading to higher losses with increasing temperature, whereas in freshwater, the loss factor decreases as temperature increases [4].…”

Analysis and Simulation of BER Performance of Chaotic Underwater Wireless Optical Communication Systems

“…High-frequency electromagnetic waves cannot be used for communication over long distances underwater due to high attenuation. In the frequency range from 1 to 3.5 GHz, the power of electromagnetic radiation is attenuated by 50 dB at a distance of about 10 cm [6]. At a frequency of 800 MHz, the attenuation of the RF signal is about 70 dB at a distance of 1 m [7].…”

On the Path Loss Model for 5-GHZ Microwave-Based Pinless Subsea Connectors

“…Recently, some developments have shown that the 2.4 GHz band is of tremendous interest for several configurations [12][13][14]. Previous studies have demonstrated the potential of this band in terms of signal propagation under several conditions [15,16].…”