Abstract: It is arduous or nearly impossible to carry out prototype experiments of large deployable space antennas because of their large apertures and the difficulty of simulating space environments on the ground. In order to solve this problem, a twostep approach is proposed in this article. The ground performance of a scale model of the large deployable space antenna is used to predict the working performance of the prototype in space. Based on this method, the structural natural frequency of the hoop truss deployable antenna working in space is studied. First, the similarity rules are derived. Second, the effect of the structural parameter distortion is taken into consideration and a similarity empirical formula of structural natural frequency is obtained. Finally, the effect of temperature change on structural frequency is studied, and the empirical formula predicting the performance of the large antenna working in space is derived. Simulation results validate the effectiveness of the method, and it can be applied to the design and performance prediction of the other space structures.

Key words: deployable antenna, prototype, models, distortion, performance