• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.147-150
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• 2005

Low actuation voltage and no contact stiction are the important factors to apply MEMS RF switches to mobile devices. Conventional electrostatic MEMS RF switches require several tens of voltages for actuation. In this paper we propose PAS MEMS RF switch which adopt PZT actuators and seesaw cantilevers to meet the above requirements. The fundamental structures of PAS MEMS switch were designed, optimized, and fabricated. Through the developed processes PAS SPDT MEMS RF switches were successfully fabricated on 4" wafers and they showed good electrical properties. The driving voltage was less than 5 volts. And the insertion loss was -0.5dB and the isolation was 35dB at 5GHz. The switching speed was about 5kHz. So these MEMS RF switches can be applicable to mobile communication devices or wireless multi-media devices at lower than 6GHz.

• Transactions of Materials Processing
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• v.11 no.2
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• pp.103-107
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• 2002

With the great demand for WDM (Wavelength Division Multiplexing) optical communications, optical switches are expected to become one of the dominant components in future networks. Conventional mechanical switches suffer from poor reliability and large size; however, many micromachined optical switches with moving mirrors have been proposed for high scale OXC (Optical Crossconnect) or ADM (Add/Drop Multiplex) because of the low power consumption and high reliability of these switches. In this paper, we introduce the technological trends of optical switches using MEMS, related micromachining technologies and their characteristics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.5
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• pp.1038-1043
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• 2003

A capacitive-coupled configuration MEMS switch is designed and fabricated, and its characteristics are measured. Low actuation voltage has been achieved by means of small distance between signal line and membrane. Minimum actuation voltage is about 11V. Isolation is around 40dB and insertion loss is about 0.2dB at 2GHz.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.4
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• pp.7-12
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• 2008

This paper presents a lateral resistive contact RF MEMS switch using comb drive. Our goal was to fabricate the RF MEMS switch with high reliability and good RF characteristics for front end module in wireless transceiver system. Therefore, comb drive is used for large contact force in order to achieve low insertion loss and small off-state capacitance in order to achieve high isolation. The single crystalline silicon is used for mechanical reliability. As a result, the developed switch showed insertion loss less than 0.44 dB at 2 GHz, isolation greater than 60 dB, and low actuation voltage at 26 V.

• Transactions on Electrical and Electronic Materials
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• v.18 no.1
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• pp.16-20
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• 2017

A RF-MEMS (radio-frequency microelectromechanical-system) based DPDT (double pole double throw) switch for the Ku band has been designed and analyzed for this article. The switch topology is based on the FG-CPW (finite ground-coplanar waveguide) configuration of a microstrip-transmission line. An FEM-based multiphysics solver is used for the evaluation of the spring constant, stress distribution, and pull-in voltage regarding the requirements of the switch-beam unit. The electromagnetic performance of the switch is investigated for a $675{\mu}m$ thick silicon substrate. For the operational frequency of 14.5 GHz, an insertion loss better than -0.3 dB, a return loss better than -40 dB, and input/output- and output-port isolations better than -35 dB are achieved for the switching unit.

• Transactions on Electrical and Electronic Materials
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• v.17 no.3
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• pp.129-133
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• 2016

Theoretical and graphical analysis of pull-in-voltage and figure of merit for a fixed-fixed capacitive Micro Electromechanical Systems (MEMS) switch is presented in this paper. MEMS switch consists of a thin electrode called bridge suspended over a central line and both ends of the bridge are fixed at the ground planes of a coplanar waveguide (CPW) structure. A thin layer of dielectric material is deposited between the bridge and centre conductor to avoid stiction and provide low impedance path between the electrodes. When an actuation voltage is applied between the electrodes, the metal bridge acquires pull in effect as it crosses one third of distance between them. In this study, we describe behavior of pull-in voltage and figure of merit (or capacitance ratio) of capacitive MEMS switch for five different dielectric materials. The effects of dielectric thicknesses are also considered to calculate the values of pull-in-voltage and capacitance ratio. This work shows that a reduced pull-in-voltage with increase in capacitance ratio can be achieved by using dielectric material of high dielectric constant above the central line of CPW.

• Transactions on Electrical and Electronic Materials
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• v.17 no.2
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• pp.92-97
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• 2016

This paper presents design and simulation of wide band RF microswitch that uses electrostatic actuation for its operation. RF MEMS devices exhibit superior high frequency performance in comparison to conventional devices. Similar techniques that are used in Very Large Scale Integration (VLSI) can be employed to design and fabricate MEMS devices and traditional batch-processing methods can be used for its manufacturing. The proposed switch presents a novel design approach to handle reliability concerns in MEMS switches like dielectric charging effect, micro welding and stiction. The shape has been optimized at actuation voltage of 14-16 V. The switch has an improved restoring force of 20.8 μN. The design of the proposed switch is very elemental and primarily composed of electrostatic actuator, a bridge membrane and coplanar waveguide which are suspended over the substrate. The simple design of the switch makes it easy for fabrication. Typical insertion and isolation of the switch at 1 GHz is -0.03 dB and -71 dB and at 85 GHz it is -0.24 dB and -29.8 dB respectively. The isolation remains more than - 20 db even after 120 GHz. To our knowledge this is the first demonstration of a metal contact switch that shows such a high and sustained isolation and performance at W-band frequencies with an excellent figure-of merit (fc=1/2.pi.Ron.Cu =1,900 GHz). This figure of merit is significantly greater than electronic switching devices. The switch would find extensive application in wideband operations and areas where reliability is a major concern.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.809-812
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• 2002

This paper presents the structures for a CPW shunt RF switch using MEMS(Micro Electro Mechanical System). Recent development in MEMS technology has made the design and fabrication of micro-mechanical switches as new switching elements. The micro-mechanical switches have low insertion loss, negligible power consumption, and good isolation compared to semiconductor switches. The fabricated structure shows an insertion loss of 2dB at 20GHz When a bias voltages of 12V is apply.

• Journal of Sensor Science and Technology
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• v.19 no.4
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• pp.320-327
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• 2010

In this paper, electrostatically actuated direct contact type RF MEMS switches have been designed and demonstrated. As driving structures of the switch, cantilever, bridge, and torsion spring beam structures are used and the actuation voltage characteristics of the switches have been compared and discussed. The designed RF switches are fabricated with the surface micromachining technology using the electroplated gold and nickel structures. The characteristics of the fabricated switches are measured and analyzed. The switch, which is fabricated using the 510 ${\mu}m$-length bridge structure with the thickness of 1.5 ${\mu}m$, is actuated with 15 V driving voltage. The insertion losses are less than 0.2 dB over the measured frequency ranges from 0 to 20 GHz and the isolations are more than 30 dB.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.652-655
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• 2004

RF MEMS is a miniature device or an array of integration devices and mechanical components and fabricated with If batch-processing techniques. RF MEMS application area are in phased arrays and reconfigurable apertures for defence and telecommunication systems, switching network for satellite communication, and single-pole double throw switches for wireless application. Recently, RF MEMS switches have been developed for the application to the milimeter wave system. RF MEMS switches offer a substantilly higher performance than PM diode or FET switches. In this paper, SPDT(single-pole-double-throw) switch are designed to use 10 GHz. Actuation voltage and displacement are simulated by tool. And stress and distribution are simulated.