I. Introduction
Electromagnetic waves with frequencies used in traditional radio communications are greatly attenuated when passing through a thick layer of conductive material, which is salty sea water. To increase the depth of penetration of the radio signal into the thickness of the earth or sea, the wavelength of the radio transmitter increases, and therefore the necessary length of the antenna elements, since they are directly dependent. Therefore, ultra-low-frequency transmitters are used to transmit control signals to deep-sea objects. The disadvantages of the known ultra-low frequency transmitting antennas are their stationary performance and, therefore, low survivability due to the very large size and known location.