Shunt-Excited Sea-Water Monopole Antenna of High Efficiency

Dynamic-type sea-water monopole antenna of high efficiency is presented by using a new shunt-excited feeding structure. The shunt-excited feeding structure is mainly formed by a conducting tube and a Gamma-shape (Γ-shape) feeding arm connected to the conducting tube near the top. An equivalent circuit model and ANSYS HFSS software are used in the analysis and design of the sea-water monopole antenna. In order to verify the validity of our design concept, two prototypes of shunt-excited sea-water monopole antennas are designed and fabricated: static-type and dynamic-type. Measured results of the two fabricated antenna prototypes are in reasonably good agreement with simulated ones, which demonstrates that the proposed shunt-excited feeding structure offers a great potential for designing high-efficiency dynamic-type sea-water monopole antennas.