Mechanical modeling of RF MEMS switches is important for performance optimization and device reliability. 1-D, 2-D, and 3-D linear analytical models have been proposed to analyze the electrostatic pull-in of a fixed-fixed beam at small deflection. However, most RF MEMS switch structures work at large deflection range. In this paper, 1-D, 2-D, and 3-D nonlinear analytical models suitable for lar...