Implementation of Low Voltage RF MEMS Switch with Different Material for Reconfigurable Antennas

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1 Asian Journal of Applied Science and Engineering, Volume 3, No 3/2014 ISSN X(p); (e) Implementation of Low Voltage RF MEMS Switch with Different Material for Reconfigurable Antennas Sardar Masud Rana 1, Rashed Al Amin 2*, Md. Nasrul Hoque Mia 3, Samioul Hasan Talukder 4, Md. Anzan-Uz-Zaman 5 1,3,5 Institute of Electronics, Atomic Energy Research Establishment, Dhaka, BANGLADESH 2,4 Department of EEE, University of Dhaka (Mymensingh Engineering College), BANGLADESH ARTICLE INFO Received: Jul 22, 2014 Accepted: Aug 5, 2014 Published: Aug 20, 2014 *Corresponding Contact rashedoni.eee@gamail.com Cell Phone: ABSTRACT RF MEMS technology can offer enhanced performance and have potential prerogatives over the conventional solid-state devices. RF MEMS Switches can be used because of their extensive electrical characterization in order to the dynamic response in low voltage. This paper presented an implemented design of a RF MEMS switch using ANSYS. After comparing Silicon, Gold and Aluminium material model, this paper also report the best RF MEMS switch model to achieve low voltage, switching frequency and low insertion loss. With applying same voltage on all models, this paper showed the Gold material model gives the most suitable result. Prefix Keywords: RF MEMS, ANSYS, Simple beam, Beam with meanders, Switch. Source of Support: Nil, Conflict of Interest: Declared. How to Cite: Rana SM, Amin RA, Mia MN, Talukder SH and Anzan-Uz-Zaman M Implementation of Low Voltage RF MEMS Switch with Different Material for Reconfigurable Antennas Asian Journal of Applied Science and Engineering, 3, This article is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. Attribution-NonCommercial (CC BY-NC) license lets others remix, tweak, and build upon work non-commercially, and although the new works must also acknowledge & be non-commercial. INTRODUCTION Micro Electro Mechanical Systems (MEMS) are the integration of mechanical elements, sensors, actuators and electronics on a common substrate using integrated circuit process sequences. The increasing demand for more flexible and low-power-consumption wireless systems which has generated the necessity for a technology that can fabricate with low temperature process, friendly with CMOS, SiGe or GaAs integration and reduce manufacturing factor with improve performance and reliability. MEMS for radio Copyright CC-BY-NC 2014, Asian Business Consortium AJASE Page 269

2 Rana etal: Implementation of Low Voltage RF MEMS Switch with Different Material for Reconfigurable Antennas ( ) frequency (RF) applications have provided an opportunity to meet these requirements which is known as RF MEMS. Due to the ability of MEMS technology for the fabrication of electro-mechanical element in a single small device ranging from 1µm to 1cm MEMs devices are rapidly used for sensor, PIN diode and Ga As based FET switches. Aircraftcondition monitoring and distributed-satellite communication is the common applications of RF MEMS switches (Norvell, etl. 1999). Reconfiguring of antenna is achieved through changing its frequency, polarization or radiation characteristics by using Radio-Frequency Micro Electro Mechanical Systems (RF- MEMS), PIN Diodes, Reactors and FETs. The switches showed good actuation on V which was observed in the experiment. According to bridge length such as 15 and 30 GHz,it is reported that the insertion loss better than 0.8 db up to 30 GHz, and an isolation of - 40 db at the resonant frequency. S.M. Rana et al. (2012) presented a RF MEMS model simulation with Silicon material. This paper presented two new ANSYS 3D simulation models by Gold and Aluminium material. After comparing these three material models with the same applied voltage from 3V to 7V it can be reported that, Gold material model provides the best suitable deflection. The dimensions of meanders beam for all models are 4 μm spacing, 4 μmwidths, 56 x 60 μm and 150 x 80 μm. GEOMETRY OF THE BEAM AND METHODOLOGY Two different types of model have been simulated in ANSYS. Simple beam and beam with meanders has been analyzed to investigate the stress, deflection, suspension and frequency. For both model, various applied voltage is performed. Rana et al. (2012) presented only Silicon material and beam with meanders for simulate RF MEMS switch but in this paper two different models andthreedifferent materials are considered. The geometry for the simple beam and beam with meanders has a height about 4µm, a gross length of 300µm, a sequence length of 80µm 50µm and the microwave t-line has 56µm 60µm. the actuation pad is smaller than the beam, so the actuation pad from the anchor is positioned about 150 µm. For both model actuation voltage and with declining electrode position consequential pull-down voltage is around3vto 7 V. To characterize the Silicon, Gold and Aluminium material; density, tensile strength, tensile yield strength, tensile ultimate strength, Young s modulus, Poison ratio and Electrical conductivity properties have been considered. Simple beam and beam with meanders models are shown in Fig. 1 and Fig. 2. Fig. 1: Simple beam model geometry in ANSYS. Page 270 Copyright CC-BY-NC 2014, Asian Business Consortium AJASE

3 Asian Journal of Applied Science and Engineering, Volume 3, No 3/2014 ISSN X(p); (e) Fig. 1: Beam with meanders model geometry in ANSYS. Appling same voltage and pressure on both model the deflection of the RF MEMS switch model is shown in TABLE 1. Table 1: Deflection of the both model with applied voltage and pressure. Beam type Voltage Deflection Pressure Deflection Simple Beam 5 Volt 0.205µm 100 pa µm Beam with meanders 5 Volt 2.85 µm 100 pa µm It is seem from output deflection, the beam with meanders model is better than the simple beam model. SIMULATION Simple beam model and beam with meanders model has been conducted on ANSYS 3D work bench module. Each parts of the both beam model has been defined in work bench. After designing the model, meshing has been performed using brick meshing method. For solution the initial and boundary conditions have been defined on beam model. After the end parts of the beam model fixed, the different voltage is applied on all material beam model t o study the deflection and stress distribution. The deflection for Silicon, Aluminium and Gold material models are shown in Fig. 3 and Fig. 4 respectively. Fig. 3: Deflection of Silicon material when 5V is applied. Copyright CC-BY-NC 2014, Asian Business Consortium AJASE Page 271

4 Rana etal: Implementation of Low Voltage RF MEMS Switch with Different Material for Reconfigurable Antennas ( ) Fig. 4: Deflection of (a) Aluminium and (b) Gold material when 5V is applied. The equivalent stress for all material with respect to the different voltage is shown in Fig. 5 and Fig. 6 respectively. Fig. 5: Equivalent stress of Silicon material when applied voltage is 5V. Fig. 6: Equivalent stress of (a) Aluminium material when applied voltage is 4V and (b) Gold material when applied voltage is 5V. Page 272 Copyright CC-BY-NC 2014, Asian Business Consortium AJASE

5 Asian Journal of Applied Science and Engineering, Volume 3, No 3/2014 RESULTS AND DISCUSSION ISSN X(p); (e) Deflection and equivalent stress for all material models with respect to different voltage is shown in TABLE 2. Table 2: Deflection and equivalent stress for all material model with respect to voltage. Applied Voltage (V) Silicon Aluminium Gold Deflection (µm) Equivalent Stress (Mpa) Deflection (µm) Equivalent Stress (Mpa) Deflection (µm) Equivalent Stress (Mpa) 3V V V V V The output graph for deflection with respect to voltage is shown in Fig. 7. Fig. 7: Applied voltage vs deflection graph for all material. The output graph for equivalent stress with respect to voltage is shown in Fig. 8. Fig. 8: Applied voltage vs equivalent stress graph for all material. Copyright CC-BY-NC 2014, Asian Business Consortium AJASE Page 273

6 Rana etal: Implementation of Low Voltage RF MEMS Switch with Different Material for Reconfigurable Antennas ( ) From the above result it is seem that, the suitable applied voltage for the RF MEMS switch is 5V.In addition, for 5V the deflection of silicon and Gold material is almost same but the spring constant and suspension of Gold material is better than Silicon (Rebeiz). So, it can be reported that the Gold material beam with meanders model is the most suitable model for RF MEMS switch. CONCLUSION MEMS based switches are and very attractive because these are small in size, low cost, reliable, accurate and high performance. This paper presented an implemented design and analyzing result of RF MEMS switch. The best suitable deflection is 2.856µm and the equivalent stress is 3.067MPa is achieved in Gold material model. By using ANSYS simulation analysis for achieve low voltage, switching frequency, better suspension and low insertion loss it had been showed the Gold material beam with meanders model for 5V applied voltage is most suitable for RF MEMS switch. REFERENCE Amit Mehta, Practical realization of dual S arm antenna for beam steering applications, Journal of Zhejiang University SCIENCE A, November 2007, Volume 8, Issue 12, pp B.R. Norvell, R.J. Hancock, J.K. Smith, M.L. Pugh, S.W. Theis, and J. Kviatkofsky, Micro Electro MechanicalSwitch (MEMS) technology applied to electronicallyscanned arrays for space based radar, IEEE Aerospace Conference, Aspen, CO 1999, pp Chang won Jung, Ming-jer Lee, G. P. Li, and Franco De Flaviis, Reconfigurable Scan-Beam Single- Arm Spiral Antenna Integrated With RF-MEMS Switches, IEEE Transactions on Antennas and Propagation, vol. 54, no. 2, February Christos G Christodolou, Youssef Tawk, Steven A Lane and Scott R Erwin," Reconfigurable antennas for wireless and space applications ", Proceedings of the IEEE, Volume 100 No.7,July D. Peroulis, S. Pacheco, K. Sarabandi, L. P.B. Katehi, "MEMSDevices for High Isolation Switching and Tunable Filtering",2000 IEEE MTT-S Int. Microwave Symp. Dig., Boston, MIT, pp , USA, June Gabriel M. Rebeiz, RF MEMS: Theory, Design, and Technology, John Wiley & Sons, Inc, page Greg H. Huff, and Jennifer T. Bernhard, Integration of Packaged RF MEMS Switches With Radiation Pattern Reconfigurable Square Spiral Microstrip Antennas IEEE Transactions on Antennas and Propagation, vol. 54, no. 2, february 2006 J. B. Muldavin, G. M. Rebeiz, "30 GHz Tuned MEMSSwitches", 1999 IEEE MTT-S Int. Microwave Symp. Dig.,Anaheim, CA, pp , USA, June J. B. Muldavin, G. M. Rebeiz, "High-Isolation Inductively Tuned X-Band MEMS Shunt Switches", 2000 IEEE MTT-SInt. Microwave Symp. Dig., Boston, MIT, pp , USA, June J. Y. Park, G. H. Kim, K. W. Chung, J. U. Bu, "FullyIntegrated Micromachined Capacitive Switches for RFApplications", 2000 IEEE MTT-S Int. Microwave Symp. Dig., Boston, MIT, pp , USA, June J. Y. Qian, G. P. Li, F. De Flaviis, "A Parametric Model ofmems Capacitive Switch Operating at MicrowaveFrequencies", 2000 IEEE MTT-S Int. Microwave Symp. Dig.,Boston, MIT, pp , USA, June Madani, S. (2014). Effect of Different Parameters on Solar Pond Performance. Asia Pacific Journal Of Energy And Environment, 1(1), doi: /apjee/2014/v1i1/53746 N.Haider, DCaratelli & A.G.Yarovoy," Recent developments in Reconfigurable & Multiband and Antenna technology", Microwave Sensing,Signal and Systems, Delft University of Technology, January S. M. Rana, M. W. Ashraf, N. Afzulpurlkar, S. Tayyaba, C. Punyasai, Simulation of Low Voltage RF MEMS Switch form Reconfigurable Antennas, IEEE EDSSC, Page 274 Copyright CC-BY-NC 2014, Asian Business Consortium AJASE