Mems Power Switch Implementation Using Sugar Simulator

In this work, a study of MEMS (Micro electro mechanical system) and SUGAR simulator is presented. A MEMS power switch is implemented and the insertion loss, return loss with respect to frequency and ON and Off states of these loss with respect to frequency is studied. Ultra low ON state insertion loss, high off state isolation and high RF signal power handling characteristics are achieved .Many of the inherent problems associated with the more traditional switches is overcome with this power MEMS switch. The SUGAR simulator is used to obtain the performance analysis of the MEMS power switch. Keywords— MEMS, Power Switch, SUGAR Simulator, [1] INTRODUCTION MEMS process is used to create tiny integrated devices or systems that combine mechanical and electrical components. These are fabricated using integrated circuit (IC) batch processing techniques and can range in size from a few micrometres to millimetres. These devices have ability to sense, control and actuate on the micro scale and generate effects on the macro scale. The complexity of MEMS is in the extensive range of markets and applications that incorporate MEMS devices and found system ranging across automotive, medical, electronic, communication and defence applications. It includes accelerometers for airbag sensors, inkjet printer heads, computer disk drive read/write heads, projection display chips, blood pressure sensors, optical switches, micro-valves, biosensors and etc. MEMS are defined miniaturized mechanical and electro-mechanical elements that are using the techniques of micro fabrication, where it vary from one micron on the lower end of the dimensional spectrum, to several millimetres. MEMS consist of mechanical microstructures, micro sensors, micro actuators and microelectronics, all integrated onto the same silicon chip as shown in Figure 1. Fig. 1 Schematic Illustration Of MEMS Components Micro sensors detect changes in the system’s environment by measuring mechanical, thermal, magnetic, chemical or electromagnetic information or phenomena. Microelectronics processes the information and signals the micro actuators to react and create some changes to the environment. These devices are very small and their components are usually microscopic. 1.1 MEMS Applications The MEMS and micromachining techniques advantages are, [1] MEMS with its batch fabrication techniques enables components and devices to be manufactured with increased performance and reliability, combined with the advantages of reduced physical size, volume, weight and cost. Journal of Theoretical and Applied Information Technology 31 st October 2014. Vol. 68 No.3 © 2005 2014 JATIT & LLS. All rights reserved. ISSN: 1992-8645 www.jatit.org E-ISSN: 1817-3195 587 [2] Provides manufacture products that cannot be made by other methods. [3] MEMS potentially are more pervasive technology than integrated circuit microchips. MEMS applications in various functional domains are used to refer to a domain in which the MEMS device performs a function (such as sensing or actuation). MEMS technology is used in various fields of the physical domain such as, [1] Mechanical (e.g., Pressure sensors, Accelerometers, and Gyroscopes) [2] Microfluidics (e.g., Inkjet nozzles), Acoustics (e.g., Microphone) [3] RF MEMS (e.g., Switches and Resonators), and [4] Optical MEMS (e.g., Micromirrors). MEMS technology has demonstrated unique solutions and delivered innovative products in chemical, biological and medical domains as well. It penetrated into consumer electronics, home appliances, automotive industry, aerospace industry, biomedical industry, recreation and sports, etc. 1.2 Classifications of MEMS The microsystems incorporate the use of microelectronics batch processing techniques for their design and fabrication. It is difficult to recently and have ability to perform high spacebandwidth product, as well as obtaining real-time encryption to unauthorized decryption and its portability [8]. Moreover, an encryption has the possibility of supporting biometric based approaches also. The polarization encryption (EP) provides additional flexibility in the key encryption design by adding a polarization state manipulation to the phase and amplitude manipulation (conventionally used in optical encryption methods) and makes EP method more secure. categorise MEMS devices in terms of sensing domain and/or their subset of MST. The classifications of microsystems technology is shown in Figure 2. Fig. 2 Classifications Of Microsystems Technology 1.3 MEMS Description MEMS technology is implemented using a number of different materials and manufacturing techniques are, [1] SiliconAbility to incorporate electronic functionality makes silicon attractive for a wide variety of MEMS applications and has significant advantages engendered through its material properties. [2] PolymersIt produced in huge volumes with a variety of material characteristics and made from polymers by processes such as injection molding, embossing or stereo lithography. It is suited to microfluidic applications also (such as disposable blood testing cartridges). [3] MetalsIt exhibits very high degrees of reliability and deposited by electroplating, evaporation and sputtering processes. 2. PREVIOUS WORK Jo-Ey Wong, et al., [2000] proposed an electrostatically actuated MEMS switch for power applications. It presented the design, analysis, fabrication and testing of an electrostatically actuated MEMS for power switch. Joo-Young Choi, et al., [2009] proposed three-dimensional RF MEMS switch for power applications. It presents a new concept in 3-D RF microelectromechanical systems switches intended for power applications. W. Simon, et al., [2002] proposed designing a novel RF MEMS switch for broadband power applications. It considers the RF power-handling capacity varies between architectural designs, which have number of diverse approaches to improve the RF power-handling capacity. D. Peroulis, et al., [2004] proposed RF MEMS switches with enhanced power-handling capabilities. The power handling capacity varies with many variables associated with the switch architecture, which has many diverse efforts to Journal of Theoretical and Applied Information Technology 31 st October 2014. Vol. 68 No.3 © 2005 2014 JATIT & LLS. All rights reserved. ISSN: 1992-8645 www.jatit.org E-ISSN: 1817-3195 588 improve RF signal power handling capacity. S. Di Nardo, et al., [2013] proposed design of RF MEMS based switch matrix for space applications.F. Maury, et al., [2008] presented RF domain is using MEMS switching devices for medium power applications is RF power. S. G. Tan, et al., [2005] presented a study of the behavior of electrically actuated RF-MEMS switches with ohmic contact. C. L. Goldsmith, et al., [1999] presented shunt microwave switches and RF MEMS variables capacitors for tunable filters. S.P. Pacheco, et al., [2000] presented the capacitive shunt switches which are actuated electrostatically with DC voltages varying between 20V and 6V. E. Sovero [1999] presented key MEMS devices for current RF architectures are switches and micro-relays in radar systems and filters in communications systems. 3. MEMS DESIGN PROCESS The basic building blocks in MEMS technology are, [1] Deposition ProcessThe ability to deposit thin films of material on a substrate [2] Lithography Apply a patterned mask on top of the films by photo lithograpic imaging, and [3] Etching To etch the films selectively to the mask. MEMS process is usually a structured sequence of the operations to form actual devices is shown in Figure 3. Fig. 3 Different Design Process used in MEMS 3.1 Fabrication process for ultra insertion loss. MEMS devices employed in RF application are termed as RF MEMS. Requirement of RF MEMS system is for low weight, less volume, low power consumption. RF devices in which a breakthrough has been achieved are micro switches, tunable capacitor, micro machined antennas. RF MEMS are manufactured using conventional 3D structure technologies like bulk and surface micro machining but LIGA and SCREAM are also used for higher ascept ratio. the materials used as the substrate is Si,SiC,GaAs etc. RF MEMS has 0.45db insertion loss,40db isolation, 70dbm linearity,40db return loss. Fully compatibility CMOS IC fabrication needs advancement is improving RF performance silicon substrate. Electroplating process. Step-1 The whole system is coated with special grade Aluminium which is micro fine (600 mesh). Step-2 Then by slow process copper is coated by pulse method [ Pulse method means the system is coated with copper and make to dry for 10 minutes again it is coated with copper and the process continue ] to get super fine structure. Step-3 The whole system is kept in sodium hydroxide [warm solution] so the aluminium dissolves and the internal part alone will be there. Step-4 Again it is coated with silver for the final structure in which the insertion loss is very less. [4] SUGAR SIMULATOR AND DEVICE IMPLEMENTATION SUGAR is an open source simulation tool for micro-electromechanical systems (MEMS) based on nodal analysis techniques from the world of integrated circuit simulation. Beams, electrostatic gaps, circuit elements, and other elements are modelled by small, coupled systems of differential equations. Sugar inherits its name from spice. It’s a simulation tool that used for MEMS. A MEMS designer can describe a device in a compact netlist format and simulate the device’s behaviour. The main components of SUGAR are [1] Netlist Interpreter (Based on LUA programming). [2] Models written in Mat Lab or C language (Describing the characteristics of different components) [3] Command line (for interaction and visualization of specific component) [4] GUI (for interaction and visualization of specific component) [5] SUGAR core (to handle Nodes, elements, Mesh assembly and analysis of the device) The devices in SUGAR are described by input files called netlists (a derivative of the Lua language). By convention, the SUGAR model functions use the familiar MKS (meter-kilogramJournal of Theoretical and Applied Information Technology 31 st October 2014. Vol. 68 No.3 © 2005 2014 JATIT & LLS. All rights reserved. ISSN: 1992-8645 www.jatit.org E-ISSN: 1817-3195 589 second) system of units. This means that beam lengths, for example, are measured in meters instead of micrometers. In order to make it easier to type lengths of microns and pressures of gigapascals, a standard system of metric suffixes that can be appended to SUGAR numbers is adopted. For example: A hundred micron length in SUGAR could be represented as 100u and in scientific notation (100e-6) or as a simple decimal (0.0001 4.1 Netlist Expressions for Length of a Beam Expressions are often used for calculation and it’s very simple inside a netlist. For example, a variable beamL for the length of a beam in a device is written as expressions, beamL = 100u -Make a beam one hundred microns long A = node {0, 0, 0; name = “A”} ... (1) B = node {name = “B”} ... (2) C = node {name = “C”} ... (3) D = node {name = “D”} ... (4) 4.2 Primitives in SUGAR It includes reserved words like node, addpath, node, material, element and subnet. The expressions (1 to 4) is possible to combined to form a beam as, beam3d {A, B ; material=p1, w=2u, l=beamL} It assigns values to the variables to perform various conditional, arithmetic and logical operations as well as in any other language such as in C or Mat Lab. Example: if a then x = a elseif b then x = b else x = c end 4.3 Operations in SUGAR The operations are illustrated in Table 1 (LUA extension). Table 1 Illustrated Operations Levels operators