Very large antenna for low frequency space-borne SAR

The recent frequency allocations for space-borne radars in P band (432-438 MHz) have aroused the interest of the scientific community. Possible applications for radars operating in this frequency band range from ice sounding to biomass monitoring. Due to the low operational frequencies and accordingly long wavelengths, the required surface for a P-band radar antenna is in the order of 60 or more square meters. Such dimensions demand lightweight and robust mechanical structures, capable of a compact stowed volume in order to be compatible with small and low cost launchers. In the frame of the ESA contracts on Very Large Space Antenna Apertures and on Passive Subarray Technological Development, Thales Alenia Space studied and proposed an innovative architecture satisfying both the high performance requirements and the mechanical constraints. Several prototypes have also been manufactured and a test campaign validated the RF design.