Development of a smart reconfigurable reflector prototype for an extremely high frequency antenna

A prototype of a space-borne smart reconfigurable reflector whose reflector surface can be changed intentionally using surface adjustment actuators has been developed, and its performance was evaluated through experiments. The smart reconfigurable reflector was designed as a sub-reflector of a space antenna for observations in the extremely high frequency band and is used for correcting the path length errors in the antenna system caused by surface deformations of the main reflector. It consists of a solid surface, supporting members, and surface adjustment actuators. The surface adjustment actuator is a key part of the smart reconfigurable reflector and consists of a piezoelectric stack actuator and a displacement magnifying mechanism. In order to investigate the performance of the actuator, functional tests were performed. The results indicate that the actuator has a stroke more than 0.9 mm with an accuracy of 0.01 mm and a force more than 90 N. The control accuracy was much better than the required surface accuracy for an EHF antenna system. The effectiveness of the developed reflector system was demonstrated through numerical simulations and shape modification experiments. In order to clarify the effectiveness of the developed smart reconfigurable reflector for the antenna system, the performance of the antenna system equipped with the smart reconfigurable reflector was evaluated. It was observed that the received power changed while changing the surface shapes of the smart reconfigurable reflector, and the changes in the power increased with an increase in applied voltage. The experimental results corresponded to the performance expected from the numerical simulation and indicated that the antenna performance was adequately controlled as expected. These results clearly indicate that the smart reconfigurable reflector system is effective for a future antenna system used for observations in the extremely high frequency band.