DESIGN AND ANALYSIS OF MEMS CAPACITIVE SHUNT TYPE SWITCH FOR RF APPLICATIONS (original) (raw)
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Novel design and analysis of RF MEMS shunt capacitive switch for radar and satellite communications
2019
In this paper, a new type of Radio Frequency Micro-Electro-Mechanical System (RF-MEMS) shunt capacitive switch is designed and studied. RF MEMS switch has a number of advantages in a modern telecommunication system such as low power consumption, easy to fabricate and power handling capacity at radio frequency. At high frequency applications, this switch shows very superior performance due to which it now became one of the key elements for RF application. In this proposed design, an innovative type of MEMS switch is designed. The MEMS switch structure consists of substrate, co-planar waveguide (CPW), dielectric material and a metallic bridge. The proposed MEMS switch has a dimension of 508 µm × 620 µm with a height of 500 µm. The substrate used is GaAs material. The relative permittivity of the substrate is 12.9. This proposed MEMS switch is designed and simulated in both UP (ON) state and DOWN (OFF) state. The proposed RF-MEMS switch is designed and simulated using Ansoft High frequency structure simulator (HFSS) electromagnetic simulator. The simulated result shows better performance parameters such as return loss (<-10 dB) and insertion loss (>-0.5 dB) in UP state, whereas return loss (>-0.5 dB) and isolation (<-10 dB) in DOWN state. This switch has good isolation characteristics of-43 dB at 27 GHz frequency. 1. INTRODUCTION The term RF-MEMS means Radio Frequency Micro-Electro Mechanical System. Therefore it is combination of two different systems that is mechanical and electrical systems. The MEMS switch exhibit both mechanical and electrical characteristics during the function. The mechanical property helps to up and down movement of RF MEMS switch for the transmission of radio frequency signal through the CPW conductor [1, 2]. This MEMS switch are extensively used for radio frequency applications [3]. Initially MEMS are used for several devices such as tempreture sensor, pressure sensor, gas chromatographs etc and at the same time MEMS switch are also used at low frequency applications [4-6]. The MEMS switches integrates the benefits of mechanical and semiconductor properties in small size. This property of MEMS switch can be used for radio frequency, hence called RF-MEMS switch. Like MEMS switch, there have alos been several standard switches such as PIN diode and FET for the switching function at RF frequency. The RF-MEMS switch provides better performances such as low power consumption, high isolation, less noise, low insertion loss, high bandwidth than the conventional solid state PINdiode and FET switches [7-8]. However, for the designing and operation of RF-MEMS switch, it has also some disadvantages such as switching speed, low power handling capacity [9-11], electrostatic discharge [12-13], high actuation voltage, packaging and low switching lifetime [14]. In order to overcome
HELIX
The electromagnetic and the electromechanical characteristics of the radio frequency micro-electro-mechanicalsystem (RF MEMS) switches for high-frequency applications are the critical performance metrics that need to optimize. Performance indices of the RF MEMS switches such as isolation, insertion loss, pull-in voltage, holddown voltage, reliability are dependent on types and properties of conducting and insulating materials that are used in the construction of switch. This article proposes the design and analysis of the two terminal capacitive shunt switches built on a coplanar waveguide (CPW) for applications in subsets of Ka-and V-Band frequency range. The proposed switch used a fixed-fixed gold membrane with the low-spring constant uniform single meander flexures support and achieved a low pull-in voltage of 5.1 Volts. An impact of the variation of the geometric parameter trade-offs like conducting membrane height, dielectric material height, and the air gap between the membrane and the dielectric materials like Silicon Nitride (Si3N4) and Hafnium Dioxide (HfO2) are studied to investigate RF and electromechanical performance of the switch.
International Journal of Computer and Electrical Engineering, 2013
This paper critically analyses the DC and RF performance of RF MEMS capacitive coupled switches with respect to changing beam geometry. Switches are designed for operation in the range 10-40 GHz. Pull-in analysis of the switch is performed with aluminum, gold, titanium and platinum as the membrane material. Simulation reveals that for the same geometry, actuation voltage of the switch with aluminum beam is 18.75 V and that with platinum beam is 27.1875 V. RF analysis shows that insertion loss as low as 0.2 dB and isolation as high as 60 dB can be achieved by proper switch design. Design and DC analysis of the proposed switch is carried out using CoventorWare 2010 and RF performance by High frequency Structure simulator (Ansoft HFSS) v 13.0
Study of RF-MEMS Capacitive Shunt Switch for Microwave Backhaul Applications
IOSR Journal of Electronics and Communication Engineering, 2017
In this research paper, we have proposed a new type of capacitive shunt RF-MEMS switch. Micro-Electro-Mechanical System (MEMS) is a combination of mechanical and electromagnetics properties at micro level unit. This MEMS switch can be used for switching purpose at RF and microwave frequencies, called RF-MEMS switch. The RF-MEMS switch has a potential characteristics and superior performances at radio frequency. The MEMS switch has excellent advantages such as zero power consumption, high power handling capacity, high performance, and low inter-modulation distortion. In this proposed design, a new type of capacitive shunt switch is designed and analyzed for RF applications. The switch is designed both in UP and DOWN-states. The proposed switch design consists of substrate, co-planar waveguide (CPW), dielectric material and suspended metallic bridge. The proposed MEMS switch has dimension of 508 µm × 620 µm with a height of 500 µm and implemented on GaAs as a substrate material with relative permittivity of 12.9. The geometry and results of the proposed switch is designed using Ansoft HFSS electromagnetic simulator based on finite element method (FEM). The electrostatic and electromagnetic result showed better performances such as return loss, insertion loss and isolation. The switch has also excellent isolation property of-48 dB at 26 GHz.
Design and optimization of a low-voltage shunt capacitive RF-MEMS switch
2014 Symposium on Design, Test, Integration and Packaging of MEMS/MOEMS (DTIP), 2014
This paper presents the design, optimization and simulation of a radio frequency (RF) micro-electromechanical system (MEMS) switch. The device is a capacitive shuntconnection switch, which uses four folded beams to support a big membrane above the signal transmission line. Another four straight beams provide the bias voltage. The switch is designed in 0.35µm complementary metal oxide semiconductor (CMOS) process and is electrostatically actuated by a low pull-in voltage of 2.9V. Taguchi Method is employed to optimize the geometric parameters of the beams, in order to obtain a low spring constant and a robust design. The pull-in voltage, vertical displacement, and maximum von Mises stress distribution was simulated using finite element modeling (FEM) simulation-IntelliSuite v8.7 ® software. With Pareto ANOVA technique, the percentage contribution of each geometric parameter to the spring constant and stress distribution was calculated; and then the optimized parameters were got as t=0.877µm, w=4µm, L1=40µm, L2=50µm and L3=70µm. RF performance of the switch was simulated by AWR Design Environment 10 ® and yielded isolation and insertion loss of-23dB and-9.2dB respectively at 55GHz.
Analytic Modeling Of RF MEMS Shunt Connected Capacitive Switches
Journal of Electromagnetic Waves and Applications, 2012
This paper deals with a general analytic approach for the design of RF microelectromechanical system (MEMS) switches. The chosen configuration for these microwave devices is composed of twocoplanar transmission line sections separated by a metal membrane providing a shunt connected variable impedance. Using a bias voltage it is possible to actuate the switch. The adopted methodology for the development of the circuital model is based on the image impedance parameter representation of a two-port network. Synthesis equations are presented, and design considerations are discussed. The proposed approach is validated by means of electromagnetic simulations.
RF MEMS Capacitive Shunt Switch: A study based practical overview
2018
This paper gives a study based practical overview of Electrostatically Actuated Radio Frequency Micro-ElectroMechanical-Systems (RF MEMS) Capacitive shunt switches. Switch configurations and their working principles are discussed. Attention is given towards design and modeling considerations of RF MEMS switches i.e. mechanical design, electromechanical design and radio frequency design aspects. Advantages and performance comparisons of RF MEMS switches against semiconductor switches and application areas are highlighted. A study of fixed-fixed gold bridge structure CPW based shunt capacitive switch with dual actuation electrodes is done for analysis and simulation of mechanical and electromagnetic characteristics. Pull-in voltage findings are 7 Volts for perforated gold bridge structure with k= 0.9276 N/m and dual actuation electrode area of 200 × 110 um2. Small capacitance switch with capacitance area of 150X70 μm2 and large capacitance switch with capacitance area of 150X150 μm2 a...
Design, Modeling and Analysis of Perforated RF MEMS Capacitive Shunt Switch
IEEE Access
This paper illustrates the design, modeling, and analysis of bridge type structure based capacitive RF MEMS switch with different beam thickness and materials. We have used Ashby's approach to select the best materials in each and every level which helped to improve the overall performance of the switch in terms of mechanical, electrical and RF properties. Silicon Nitride thin film (ε r = 7.8) is used as a dielectric material. The beam structure stiffness is analyzed with different materials such as gold, titanium, and platinum, with in these materials gold with high thermal conductivity and Euler-young"s modulus of 77 GPa is offering the best performance. Incorporation of meanders and perforations to the membrane helped to reduce the pull-in voltage. The proposed switch is offering very low pull-in voltage of 1.9 V. The deflection of beam thickness is tabulated for the three materials among them the 2 um thickness is best beam thickness for the switch for X-band applications. The switch offers best return loss (S 11) of-21.36 dB, insertion loss (S 12) of-0.147 dB, and isolation (S 21) of-52.04 dB at 8GHz. The switch presented in this paper is preferable in X-band applications.
Integrated Modeling of Mechanical and RF Performance of MEMS Capacitive Shunt Switch
2000
This paper describes a method to combine MEMS mechanical and RF design and simulation. To demonstrate the method a MEMS capacitive shunt switch is designed and simulated using the CoventorWare 3D finite-element software package. Device profiles from this package are imported into the CST Microwave Studio 3D EM simulation package and the RF performance of the MEMS switch is assessed
A NOVEL MODEL OF RF MEMS SHUNT SWITCH
The advancement in the Radio Frequency Micro-Electro Mechanical Systems (RF MEMS) switch has enabled new technologies for microwave switching applications. It is the method used for reduction of material used which in turn decreases the cost and the power dissipation. The RF MEMS shunt switch is constructed for high frequency microwave switching. The switch is driven by electrostatic actuation. The contact line and the RF signal line behaves as the parallel plate capacitor. The Switch provides a good isolation in the off state and less insertion loss. The geometry parameters of the switch is chosen such that the switch can be easily integrated. The Switch Niobium metal is used for the contact lines as it has good superconducting characteristics in cryogenic temperature. The performance of the switch is analyzed and the result shows the deformation of the switch with low actuation voltage.