Antenna development for MetOp Second Generation wind scatterometer

This paper describes the wind scatterometer instrument on board the MetOp Second Generation satellites and the associated antennas, which are under development for launch in the 2020 time-frame. The new scatterometer instrument, operating at C-band (5.3 GHz), requires 6 fan-beams in order to measure ocean backscatter at different azimuth angles with respect to the satellite track. Vertical polarization is required for all 6 beams whereby the Mid-beams (in the across-track direction) shall also receive radar echoes in horizontal polarization. The requirements for the antennas are challenging in terms of gain stability, high peak gain, polarization purity and very high power handling (a few kW). The two companion papers [1, 2] describe two different antenna design solutions implemented respectively by Airbus Defence & Space (ADS) and RUAG Space (RUAG).