Development of a novel actuator for the Application of a reconfigurable reflect array antenna

With the advancement of spacecraft payload technologies, multi-functional antennas are increasingly in demand This paper presents a planar reconfigurable antenna technology that combines reflectarray antenna technology and micro-actuator technology. This antenna can realize wide angle beam scanning by rotating all patches simultaneously. Every patch is rotated by an innovative micro-actuator. This paper is mainly divided into three parts. The first part describes the patch of the antenna. The concentric dual split-rings patch structure is designed and analyzed. The Radio Frequency (RF) phase was found to be almost a linear function of the rotating angle of the patch. To verify the RF performance of this antenna, an antenna with 756 patches was designed and simulated. Simulation results show that the antenna has high gain and aperture efficiency. Finally, a novel rotational actuator was designed, optimized, fabricated, and tested. Unique characteristics of this actuator include small volume, low energy consumption, high controllability, fast response, and high reliability. These characteristics are essential to the successful performance of this antenna. For the architecture of this actuator, bimorphs were used as the driving units and micro-gears were used to form the transmission system. This actuator can rotate clockwise and counterclockwise alternately by altering the applied voltage. The control system is simple and easy to implement; only feedforward control is required. For a positioning application, this actuator does not have any accumulative error. The geometry of this actuator was optimized using the multi-physics coupling finite element method (FEM). Components of the actuator were fabricated by micro-electric-mechanical-system (MEMS) fabrication processes and precise machining technologies. Glass fiber reinforced composite (GFRC) and Lead Zirconium Titanite (PZT) materials were used to fabricate the bimorph. Copper and stainless steel were used to fabricate the housing and the gear, respectively. Several actuators were assembled and tested to investigate their characteristics. The relationship between the rotating angle and the applied voltage was studied both analytically and experimentally. In addition, response time was assessed using a high-speed camera.