Advanced Research in Electrical and Electronic Engineering Print ISSN: 2349-5804; Online ISSN: 2349-5812 Volume 1, Number 3 (2014) pp. 25-28 © Krishi Sanskriti Publications http://www.krishisanskriti.org/areee.html Simulation of Capacitive Shunt RF MEMS Switch for Low Actuation Voltage using Coventorware 2012.000 Deepankar Saini 1 , Rakesh Narwal 2 , Anil Gurjar 3 , Mukesh Kumar 4 , Dinesh Kumar 5 1 M.Tech Student, Electronics Science Deptt., Kurukshetra University Kurukshetra 2 Research Scholar, Electronics Science Deptt., Kurukshetra University Kurukshetra 3,4 Electronics Science Deptt., Kurukshetra University Kurukshetra 5 Chairman, Electronics Science Deptt., Kurukshetra University Kurukshetra Abstract: The design of capacitive shunt RF MEMS switch for low actuation voltage is described. The switching element is a thin metallic membrane which has two states: up and down. A RF signal can be transmitted or blocked through these states. Electrostatic actuation mechanism is used to actuate the membrane by applying a voltage bias to actuation electrode. The actuation voltage is reduced by using meander structure and reducing the air gap between electrode and membrane. The optimized actuation voltage comes out to be 5.3 volts which is comparable to contemporary MOS switches. Major advantage over MOS switch is negligible power dissipation. Keywords: RF MEMS switch; Actuation voltage; Anchors; Air gap. 1. INTRODUCTION As early as 1979, microelectromechanical switches have been used to switch low frequency electrical signals. Since then, switch designs have utilized cantilever, rotary and membrane topologies to achieve good performance at RF and microwave frequencies [7]. Radio frequency (RF) microelectromechanical systems (MEMS) switches have found applications in several communication systems. These applications require signal conditioning circuitry which is usually fabricated on low resistivity silicon using IC fabrication technique [8]. RF MEMS switches are low cost, high performance devices used for radio frequency switching now days because of their potential benefits over contemporary switching devices. Development in technology has made possible switching of high frequency signal through these devices. The moving metal contacts have low parasitics at microwave frequency hence become beneficial to achieve high on state capacitance [3]. RF MEMS switch has many advantages over FET switches like negligible power consumption, very high isolation, very low insertion loss etc. RF MEMS switches have a lot of advantages over their counter parts, however they have their own set of problems. The major shortcomings include the switching time, high actuation voltage and reliability. 2. SWITCH OPERATION The switch is actuated using electrostatic actuation by applying a dc voltage bias on actuation electrode. This type of switch works opposite as compared to its counterparts. When no bias is applied to actuation electrode switch is in up state and transmission of RF signal takes place through the coplanar waveguide transmission line. On other hand when sufficient voltage bias called actuation voltage is applied to actuation electrode the membrane snaps down and switch is in down state then RF signal is capacitively shunted to the co-planar grounds through the metallic membrane and transmission is off, hence, it require zero or negligible power for operation. The two states of switch operation are as shown in the figures 1 and 2. Figure 1. Up state of switch