Nowadays naval industry increases its technical requirements in order to adopt or update its efficient wireless communication technologies for data transmission in underwater environment.
These technologies are developed in a different set of applications: environmental monitoring, advanced control of electro driven underwater equipment (unmanned vehicles), and, in general, when technical focus is related to instruments that are equipped with sensor and controls on-board.
Hence, current challenge of designers about this topic is to conceive reliable electromagnetic devices for communication applications and they have to be suitable for use in environments intrinsically hostile to radiofrequency propagation, like water or oil.
The recent standard communication protocol, IEEE 1902.1, released by IEEE Committee on March 2009 aimed the technical interest about the new technical challenge. Low frequency, long wave magnetic signal, short data packet, and low power consumption identify that this protocol is the optimal candidate to set new communication techniques in underwater environments.
All the technical efforts started from IEEE1902.1 analysis and investigation of different antennas types, either for geometrical characteristics and transmission modes, and two suitable different types of antennas have been identified; they were modeled and analyzed through fem technology, and a set of technical specifications has been issued for their manufacturing. Finally both physical prototypes and industrialized items have been tested and validated.
The paper summarizes main results of scientific interest; they are out of application of traditional high-frequency but FEM analysis methodologies were used into the domain of low frequency transmission, and near field condition with electric field decoupled from the magnetic one and all the results were successfully closed to final product realization.
|