Description
The objective of this activity is to design, manufacture and test a partial RF breadboard of a transmit Ka-band, active phased array antenna and associated beamforming network for user links NGSO, exploiting irregular layouts for the radiating elements and beamforming networks.Targeted Improvements: In comparison to a standard, fully populated array:- 25% reduction in the number of active controls,- 5% increase in the DC to RF power efficiency at antenna level due to the reduced exploitation of amplitude tapering,- 15% reduction in the overall mass for the entire antennaDescription: After two decades of research and development sparse arrays have been successfully deployed in space, although not by European companies. The main advantages offered by aperiodic arrays include:- sidelobe levels that may be controlled by implementing a density-tapering strategy with a reduced exploitation of the amplitude tapering;- a reduction of the number of radiating elements for a given aperture size with a limited reduction of the beamwidth;- anaperiodic spatial distribution that allows spreading and controlling the grating lobe power;- suitability for wideband applications thanks to the reduction of grating-lobe levels;- less problematic mutual coupling thanks to the unequal inter-element spacings.In this activity, active phased array antennas exploiting sparse radiating element layouts and sparse topologies for beamforming networks shall be developed for Non-Geo-Stationary-Orbit (NGSO) satellite user links. One of the main challenges is the design of beamforming networks compatible with irregular layouts for the radiating elements. The difficulties are not only related to RF aspects; accommodation and thermal control are also of paramount importance and require consideration due to the non-homogeneous character of the power generation and dissipation caused by the irregular distribution of array control centres. For this reason, transmit and receive operations could be implemented in two separated antenna apertures. Single vs dual-polarisation operations shall be traded off,and the two most promising and sufficiently different architectures shall be identified for a detailed design covering RF, mechanical and thermal aspects. The most critical components should be identified, manufactured, and tested.