To develop multibeam antennas based on passive reflectarrays and/or transmitarrays. The new antennas shall be designed to generate multiple spot contiguous beams for broadband applications or multiple shaped beams for broadcasting.

Reflectarrays and transmitarrays can be designed to steer the reflected and transmitted beam away from the specular direction or to shape it according to preassigned requirements. Their properties can be tuned also with respect to the frequency. Their increased number of degrees of freedom may be beneficial in the design of multibeam antennas. The main expected improvements are: 1) the reduced number of apertures with respect to architectures based on conventional reflectors; 2) the planarity of the panels with benefits in terms of accommodation and deployment; 3) minimized crosspolarized components. The main expected criticalities are: 1) discrimination in frequency: contiguous beams have to work at different frequencies really close one each other; 2) discrimination in angle: contiguous beams have point in different directions; 3) discrimination in polarization: contiguous beams have to exhibit different polarizations (circular or linear).The activity will be organized in 4 parts: 1) identification and preliminary design of reflectarray and transmittarray antenna architectures suitable for the generation of multibeam coverages as defined in operational Telecom missions; 2) detail design of a promising configuration; 3) identification, design, manufacturing and testing of the most critical components needed to validate the antenna concept; 4) comparison in terms of RF performances but also mass, cost and complexity between the multibeam antenna based on reflectarrays and/or transmittarrays and a conventional reference antenna. The activity is proposed by TEC-EEA in coordination with TEC-ETP and TEC-SBS.