ABSTRACT

This chapter focuses on the design, development and complete characterization of a push–pull type of microelectromechanical systems (MEMS) actuator. It draws on the utility of the push–pull bridge. The concept of the push–pull actuator is validated using an analog-type distributed MEMS transmission line phase shifter topology, which gives us the ability to achieve a complete differential phase shifter with a very low actuation voltage at 40 GHz frequency. A systematic analytical design methodology of the push–pull actuator is comprehensively worked out and discussed. The microelectromechanical push–pull actuator works on the principle of electrostatic actuation. The push–pull actuator and a complete phase shifter is fabricated using a simple surface micromachining process on 635 µm alumina substrate. The push–pull bridge is thoroughly characterized for its mechanical response using laser Doppler vibrometer. The effect of dielectric charging affects the reliability on the device performance due to low stiffness and inhomogeneous distribution of trapped charges.