| Popis: |
This paper explores the possibility of using spin-stabilized membrane structures for large phased array microwave antennas (typically L-Band or S-Band from 1 GHz to 4 GHz). The biggest challenge is to be able to sufficiently stabilize the system in order to limit its sensitivity to space disturbances (maneuvering, reaction wheels, and other imposed forces) and manufacturing imperfections. First, a flatness requirement for microwave antennas is derived. Then a frequency analysis of orthotropic flat structures spinning at different angular velocities and with different bending stiffnesses is carried out. These analyses, together with finite element simulations, are used to derive scaling laws to study the behavior of structures spinning in space. A test case, based on a spinning structure perturbed at the hub, is considered. An analytical solution of the free vibration of this test case is compared to the results of finite-element method simulations with Abaqus/Standard. Finally a test setup to study the dynamics of scaled spinning membranes in the laboratory is presented. Gravity effects in such an experiment are expected to be small. |
