Optimizing Beam Congruence of a Solid Cassegrain Reflector and an Offset-Fed Deployable Mesh Reflector

Two multi-beam Ku-band reflector antennas are designed for a NASA’s Earth Science mission concept. This satellite could carry two antennas: a center-fed Cassegrain fixed reflector and an offset-fed deployable mesh reflector. Each support 7 near-nadir beams at Ku-band with matched patterns between the two antennas. The feeds are arranged to achieve a desired cross-track overlap at the 1.5 dB point of the antenna pattern. This solution takes advantage of the platform motion to achieve the desired scan pattern with a simple switched-horn solution. This paper describes the design approach of the two antenas to achieve identical beam pointing and beamwidth despite using different optical prescription.