Development of Multi-beam Ka-band Mesh Reflector Antenna for NASA INCUS Mission

This paper presents the design, development, and performance evaluation of a multi-beam Ka-band 1.6m deployable offset mesh reflector antenna for NASA’s INCUS mission. The mission involves three time-spaced observatories aimed at providing Ka-band observations of tropical atmospheric convection. The antenna incorporates a seven-feed cluster with partially overlapping beams, which relaxes pointing accuracy requirements while maintaining adequate ground coverage and high gain. A robust reflector design features tensioned dual-net construction, ensuring precise deployment and surface stability. This paper details the critical aspects of the antenna design, including the feed, detailed simulations for multi-beam performance, RF performance of the measured reflector surfaces, and the effect of on-orbit thermo-elastic distortions. The reflector’s performance was extensively validated through multiple deployment trials of an engineering development unit, which showed high repeatability of the reflector shape and a minor positional uncertainty. Using an optimized average feed position derived from these tests, the antenna demonstrated a consistent RF performance within the mission’s requirements. Thermal performance analyses further evaluated dynamic pointing and gain stability under orbital temperature variations. The reflector antenna is expected to meet mission needs for high-resolution atmospheric observations, with flight units currently in production.