Minimizing scattering from a densely packed antenna boom on the Europa Clipper Spacecraft

The placement of multiple antennas onto a single antenna boom on a spacecraft is often done to meet size and mass requirements. On the Europa Clipper spacecraft, one particular boom consists of three unique antennas and an instrument, a sun-sensor. The co-location of these can cause strong scattered fields that can degrade the radiated fields from the antennas. These degradations manifest as ripples or deep nulls in the radiation pattern, resulting in lower data-rates or complete loss of the communications link. To minimize these degradations, a numerical solver based on the Method of Moments (MoM) was used to solve for the scattered fields. The scattered fields are then minimized through an iterative process of changing placement and orientation of the boom's constituents. To validate this approach, a mockup of the antenna boom was constructed and tested in a compact antenna range. The results showed that the measured mockup and modeled radiation patterns compare well, showcasing the value-add of the electromagnetic scattering analysis in-lieu of an expensive full-scale prototype mockup.