Design of a temperature-stable RF MEM capacitor

This paper presents a novel temperature-compensated two-state microelectromechanical (MEM) capacitor. The principle to minimize temperature dependence is based on geometrical compensation and can be extended to other devices such as MEM varactors. The compensation structure eliminates the effect of intrinsic and thermal stress on device operation. This leads to a temperature-stable device without compromising the quality factor (Q) or the voltage behavior. The compensation structure increases the robustness of the devices, but does not require any modifications to the process. Measurement results verify that the OFF and ON capacitance change is less than 6% and the pull-in voltage is less than 5% when the temperature is varied from -30 to +70°C.