| Περίληψη: | The present study concerns the student's study and familiarization with the various types of deployable antenna technologies for space applications, which have been successfully developed and operated on a space mission. The ultimate goal is the creation of appropriate theoretical bases and a general understanding of the key elements of each technology as well as the advantages and disadvantages of implementing this specific type of antenna on a mission. After this research, the design, analysis and finally optimization of a deployable antenna that meets the specifications given by the Applied Mechanics and Vibrations Laboratory, may successfully be launched. The deployable antenna shall be truss structure with a 1-meter parabolic reflector. The available stowage volume is 10 × 10 × 30 3.
Initially, the creation of an efficient deployable mechanism, which will be characterized by simplicity, reliability, low weight and cost as well as high ease in the production process is an important first step that will determine the subsequent analysis. The stiffness of the structure is of the utmost importance, as it holds the parabolic mirror and shapes the geometry of its surface, directly affecting the power of the signal it emits. In addition, the kinematic analysis of the structure is necessary, and to be more specific the study of the angular velocity, the angular acceleration, the necessary engine torques as well as the internal spring forces. The antenna deploys itself in 2 minutes with the help of stepper motors and springs. Dynamic analysis using the finite element method provides us with details about the resonant frequencies of the structure, the maximum deformations, stresses and strains at each phase (launch, final phase of operation) as well as the critical components at risk of failure. Finally, a basic radio frequency analysis (RF analysis) was performed and the antenna gain was calculated.
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