MOSAIC aims at improving the technical and commercial maturity of the antenna architectures proposed in the ESA invention [1] which describes a design and manufacturing method for large sparse phased arrays for geostationary orbit satellite. Sparse arrays offer power consumption reduction through a not regular lattice, at the cost of increasing the complexity of the BFN as well as a not complete filling of the available aperture.
The main idea of MOSAIC consists in adopting a modular structure, based in subarray, to simplify the antenna architecture and the manufacturing. In particular, the elements of the array are grouped into square tiles of different sizes (2 or 3 at the maximum). This choice makes the whole array architecture more regular as compared to the one considered in [1] since the antenna phase centers may be located in a regular lattice, thus will lead to the design and implementation of a simplified BFN. Moreover, the square tiles allow a complete filling of the aperture, maximizing the aperture efficiency. In order to further reduce the manufacturing costs and increase the antenna robustness, each tile will be controlled by a single isophoric amplifier and a simplified phase tapering to possibly shape the subarray radiation pattern. Exploiting the invention, the single antenna elements will be co-designed with the sub-array layout in order to optimize the shapes of the subarrays patterns with the aim of reducing the scan loss. Regarding the elementary radiator, a full-metal antenna element is envisaged.
The activity includes the manufacturing and test of one or more subarray breadboards to validate the proposed low-cost solution. The targeted mission is the micro-GEOstationary satellite that SWISSto12 is developing with the support of ESA. The consortium believes that the original invention, and hence this activity, have the potential to enable a competitive use of phased arrays in platforms whose DC capabilities are limited.
