Applications of Reflectarray Technology for Radio Astronomy Interference Mitigation

High-gain reflector antennas commonly used to make observations in radio astronomy are especially susceptible to the reception of undesirable radiation through their sidelobes. One source of this radiation is megaconstellations associated with satellite based communications systems. In this paper, we present some recent advances in the application of reflectarrays for mitigation of interference from these megaconstellations. By placing a reflectarray along the rim of a reflector and thereby repurposing reflections to generate destructive interference to unwanted incoming radiation, interference can be nulled. The first example is a dual band reflectarray capable of producing a null to track interference throughout the sidelobe envelope in two frequency bands associated with Iridium and Starlink satellite systems. The second example is a proof-of-concept demonstration utilizing a C-band planar reflectarray of which the elements along its perimeter are made reconfigurable. Both examples point to the possibility of utilizing reflectarrays for radio astronomy interference mitigation.