학술논문

Formulae for the Impedance and Transmission Factor of an Electrically Small Half-Sheath Dipole Antenna Immersed in Seawater
Document Type
Periodical
Source
IEEE Antennas and Wireless Propagation Letters Antennas Wirel. Propag. Lett. Antennas and Wireless Propagation Letters, IEEE. 21(3):640-644 Mar, 2022
Subject
Fields, Waves and Electromagnetics
Impedance
Transmitting antennas
Electric fields
Radio frequency
Electrodes
Dipole antennas
Electronic countermeasures
Antenna impedance
electrically small antennas
seawater
transmission factor
underwater
Language
ISSN
1536-1225
1548-5757
Abstract
To develop optimal antennas for underwater radio frequency communication, we formulate the impedance and the transmission factor of an electrically small half-sheath dipole antenna immersed in seawater and validate the results by comparing them with full-wave electromagnetic simulations. The derived formulas are quite practical because they express the impedance and the transmission factor only in terms of the antenna dimensions and the physical properties of the medium. Furthermore, they reveal that the transmission factor increases with decreasing impedance, thus providing important insight into designing underwater antennas.