- Fig. Proposed configurations for the radiating elements in presence of a simplified realistic model: three-arms dipole (a), three-arms monopole (b), optimized meandered antenna (c).
- Fig. Proposed configuration for the miniaturized slot antenna at VHF band. The thickness is λ/130, whereas planar dimensions are lower than λ/2
- Fig. Prototypes of antennas as derived from studies of SHIRED project: three-arms monopole (a), optimized meandered antenna (b). Photographs taken during measurement campaign at laboratories of Istituto Vallauri in Tirrenia (Pisa).
- Fig. Radiation pattern of a shipboard array at 15 MHz obtained through full-wave simulation employing optimized feeding factors.
The project is relevant to the definition of new architectures of the radiating elements of telecommunications and radar systems operating on board of mobile units. In particular, attention is focused on the definition and the design of novel compact antennas, maintaining high performance from an electromagnetic point of view. In a side activity of the same researchers, regarding the definition of novel configurations acting as virtual magnetic ground planes, showed the feasibility of very low profile antennas built on such high impedance surfaces. Recent studies have also shown that, if properly designed, such surfaces are able to reduce the RCS of antennas outside the operating bandwidth. Such properties are very well suited to reducing the total geometric occupancy with respect to conventional HF and VHF shipboard antennas. It is important to highlight that, at these frequency bands, the antennas can be tailored to the geometry of the ship so to consider the whole structure as a radiating element, with a clear improvement of the final performance.
The objectives of the project are:
- the conclusion of the theoretical analysis, also considering the antenna interaction with the operational environment;
- the design of a specific radiating element with predetermined characteristics and the construction of a scale model of the antenna, to be tested both in free space and in the presence of a simplified model of the ship;
- the manufacturing of an antenna prototype, to be experimentally tested.