Computational Prototyping of an RF MEMS Switch using Chatoyant

By controlling the degrees of freedom for the components in the system and using a PWL solver, a tradeoff between speed and accuracy is realized. Electrical components are modeled using a similar MNA technique. The interaction between electrical and mechanical components is accomplished by modeling the coupled energy between the domains. In this paper we demonstrate the capabilities of our system-level CAD tool, Chatoyant, to model and simulate an RF MEMS switch. Chatoyant is a mixed signal, multidomain CAD tool that can be used to design and analyze complete mixed-technology micro-systems. We perform a system level simulation of an RF MEMS switch. This is accomplished by coupling mechanical and electrical domains of this system. We verify our mechanical results using the commercial simulation packages, ANSYS, and CoventorWare. 2 RF MEMS DEVICE The RF MEMS device we model was designed and fabricated at the University of Michigan [2, 3]. It is composed of electrostatic actuation plates and a capacitive plate suspended over a coplanar waveguide by spring meanders (Figure 2). This device works as an electrically switched shunt capacitor. With no voltage applied to the actuation pads, most of the RF signal can pass through the signal line. Applying a voltage to the actuation pads, results in an increase in the coupling capacitance between the signal line and the central capacitive plate. This lowers the impedance between the signal and ground, which effectively “shunts” the RF energy to ground and stops the RF propagation through the signal line [4]. The sensitivity of the device is directly related to the number of meanders in the spring assembly. Increasing the number of meanders will ideally lower the required voltage for switch operation. For this research, we considered a device having four meanders.