Deformation of the DC support capacitor housing

Can MEMS variable parallel plate capacitors deform a movable plate?

However, MEMS variable parallel plate capacitors often experience deformation of the movable plate, then the electric filed becomes nonuniform and the expression of calculating the capacitance and the pull-in voltage becomes invalid. In this paper, we model the deformation of the movable plate and analyze the mechanical behavior of the capacitors.

What is a variable capacitor on a substrate?

It consists of two parallel plates, four T-shape beams to suspend the top plate, the air is between the top plate and bottom plate. When voltage is applied to the two pads, the top plate will be pull down because of electrostatic force. When the parallel Fig. 1. Schematic illustration of variable capacitor on substrate.

How do MEMS variable capacitors work?

Because electrostatic actuation and air dielectrics have led to devices with low power consumption and high quality factors, MEMS variable capacitors with two plates (one movable plate and one fixed plate) have been fabricated. When a dc voltage V is applied across the capacitor, the movable plate is pulled down to the fixed plate.

How to measure the electromechanical behavior of a variable capacitor?

The electromechanical behavior of the suspension, the surface profile of the variable capacitor at different values of applied voltage is measured using WYKO NT1100 optical surface profiler. The change of the spacing as a function of the applied voltage is extracted from the surface profile measurement.

When does a parallel plate variable capacitor pull in?

For electrostatically actuated parallel plate variable capacitors in conventional theory, pull-in occurs when the deflection of the movable plate is one-third of the original air gap. However, the electrostatic force is nonlinear, only the center of the movable plate nearly fully reached their maximum displacement when pull in occurs.