Antenna subsystem far-field characterization of the spin-stabilized satellite Eu:CROPIS

In this paper, we present the far-field characterization of the antenna subsystem of the Eu:CROPIS (Euglena and Combined Regenerative Organic-Food Production in Space) satellite. Its specialty, in contrast to other satellite missions, is the spin-stabilization used in order to simulate the Moon and Mars gravitational fields for the biological on-board experimentation. Thereby, spin rates of up to 30 rpm are obtained, which have influence on the communication link. From the perspective of the ground station, the far-field becomes dynamical, including phase rotations and amplitude variations. Both can degrade the communication link and might lead to a loss of signal. Hence, a detailed analysis of these destructive phenomena is essential to be able to test possible effects on the receiver electronics beforehand and to avoid such issues in orbit. The far-field characterization is therefore an essential part of the overall design and verification process. It is initially performed by an Electromagnetic (EM)-field simulation, utilizing a (Multi-Level Fast Multipole Method) MLFMM-solver. After the identification of critical regions a mock-up based measurement in an anechoic chamber is performed to verify the simulated results. This paper introduces both characterization methods and compares the results.