Shape optimization in mechanically reconfigurable antennas

This paper describes the optimization methodology to mechanically reshape an antenna deformable reflector with a set of actuators in order to produce a desired contoured beam. The set of actuator commands for reshaping the reflector is determined by global optimization with Simulated Annealing. The optimization consists of minimizing the maximum stresses arising in the reflector structure when it is reshaped, while Radio-Frequency (RF) performance requirements such as the Directivity (D) and the Cross-Polar Discrimination (XPD) are specified as constraints. This optimization couples a Finite Element Analysis for the calculation of both the mechanical stresses and the reflector shape response to the actuator commands, with a RF analysis to meet the coverage requirements. This process allows to very significantly reduce the maximum principal stresses in the reflector in comparison to the ones produced by a pure RF optimization. These results can be considered as enabling the technology of mechanically reconfigurable reflectors for providing enhanced flexibility of Telecom and Earth Observation missions, while guaranteeing the strength and stability of the antenna structures.