Maximization of scanning range for a piezo-driven antenna orientation stage

Abstract

A piezo-driven antenna orientation stage is presented where two pairs of rhombic piezoelectric actuators (RPAs) are used to achieve the out-of-plane antenna motion, and the scanning range of this stage is maximized by maximizing the strokes of the RPA pairs. Two maximization strategies are implemented and compared. The first is based on an analytical model, and the second is based on a finite element (FE) model. The analytical model usually shows large errors because of the simplifications that must be made during structural analysis and because it ignores the electromechanical coupling characteristics of the piezo-stack. In contrast, the FE model can provide much more accurate solutions by considering the piezo-stack and its electromechanical coupling characteristics. Then, the particle swarm optimization (PSO) method, which is independent of the mathematical models, is used to determine the optimal FE model parameters. In this way, more accurate optimal geometrical parameters are obtained for the rhombic amplifier. Finally, two specimens, which have different optimal geometrical parameters from the analytical and FE models, are fabricated and tested for comparison. The experimental results show that the optimization method based on the FE model is feasible, and is more accurate and efficient.