Duration: 18 months
Future LEO constellations are considering the possibility to move TT&C functionalities to the Ka-band, using a dedicated channel within the frequency bandwidth typically allocated to the user and feeder links. This allows combining the feeder links and TT&C functionalities on the same ground station antennas, simplifying the overall system architecture. Antenna systems under evaluation comprise four single-band antennas, two (one transmit and one receive) down-looking and two up-looking. There is an interest in combining the pair of antennas in each side of the satellite into a single dual-band solution. While TT&C functionalities typically require a reduced fractional bandwidth, it is more advantageous from an industrial perspective to produce a generic design providing full flexibility to end customers on the frequency allocation. In this context, the ESA invention PAT 782 is a promising building block for the design of such antennas, providing a very compact dual-band dual-polarisation exciter that combines all desired functionalities within a very small envelop and with a fully generic design. The proposed activity is intended to evaluate that specific technical solution for the purposes identified by adjusting its design to specifications compatible with recently received RFIs and RFQs. As part of the commercial maturation, alternative manufacturing techniques will also be evaluated, in view of recent improvements making additive techniques promising for millimeter-waves components. The activity shall also evaluate the radiating part, which requires innovative ideas to achieve hemispherical patterns in both bands and over the complete frequency bands for a completely generic design. Alternatively, an adjustable narrow-band design could be considered for that part, inspired from dual-band hemispherical GNSS antenna solutions.
