Low actuation voltage totally free flexible RF MEMS switch with antistiction system (original) (raw)

Low Voltage Totally Free Flexible RF MEMS Switch With Anti-Stiction System

This paper concerns a new design of RF MEMS switch combined with an innovative process which enable low actuation voltage (<5V) and avoid stiction. First, the structure described with principal design issues, the corresponding antistiction system is presented and FEM simulations are done. Then, a short description of the process flow based on two non polymer sacrificial layers. Finally, RF measurements are presented and preliminary experimental protocol and results of anti-stiction validation is detailed. Resulting RF performances are -30dB of isolation and -0.45dB of insertion loss at 10 GHz. I.

Design of low actuation voltage RF MEMS switch

2000

Low-loss microwave microelectromechanical systems (MEMS) shunt switches are reported that utilize highly compliant serpentine spring folded suspensions together with large area capacitive actuators to achieve low actuation voltages while maintaining sufficient off-state isolation. The RF MEMS switches were fabricated via a surface micromachining process using P12545 polyimide as the sacrificial layer. The switch structure was composed of electroplated nickel and the serpentine folded suspensions had a varying number of meanders from 1 to 5. DC measurements indicate actuation voltages as low as 9 V with an on-to-off capacitance ratio of 48. Power handling measurement results showed no "self-biasing" or failure of the MEMS switches for power levels up to 6.6 W. RF measurements demonstrate an isolation of -26 dB at 40 GHz.

Design of H-shaped low actuation-voltage RF-MEMS switches

2006 Asia-Pacific Microwave Conference, 2006

Low actuation-voltage and high reliable microelectromechanical systems (MEMS) shunt capacitive and shunt resistive switches are in this paper proposed. Electrostatic-mechanical coupling using finite element method (FEM) and full-wave electromagnetic (EM) analyses have been performed. The mechanical design of a low spring-constant switch structure has been optimized by calculating the dependence of the actuation voltage on the membrane shape, material properties and geometrical sizes. The proposed switches, based on Al metallization membrane, show a pull-in voltage around 7 and 13 Volts with 0 and 20 MPa residual stresses, respectively. The simulated insertion losses are less than 0.25 dB up to 40GHz with a return loss of about 20 dB in the ONstate. The isolations in the OFF-state for the capacitive-switch are greater than 20 and 35 dB at 12 and 40 GHz, respectively. The shunt resistive switch theoretically works from zero frequency with isolation greater than 25 dB up to 40 GHz. The fabrication of those switches is compatible with standard CMOS technology and they are in process. Index Terms -Low-actuation voltage, MEMS, Pull-in, RF MEMS switch.

RF MEMS Switches Supported by Polymeric Structures

2007 International Semiconductor Conference, 2007

RF MEMS shunt switches in coplanar waveguide (CPW) configuration have been designed, realized and tested for wideband isolation purposes. SU-8 negative photo-resist technology has been introduced for improving the bridge mechanics and the RF performances of the device. The polymeric material is used to elevate the ground planes of the CPW structure, with minor consequences on the electrical matching and an improvement in the bridge ends definition. The EM design has been followed by a sixstep photo-lithographic process on a 4" oxidized high resistivity silicon wafer, up to the release of the bridge by using a plasma etching technique.

A stiff and flat membrane operated DC contact type RF MEMS switch with low actuation voltage

Sensors and Actuators A: Physical, 2009

RF MEMS switches can be divided into electrostatic, magnetic, thermal, and piezoelectric types by their actuation mechanisms. Most research has focused on the electrostatic actuation types because of these types low power consumption, simple fabrication method, and good RF characteristics. However, these types of switches operate at high voltages compared with the other types. One of the main problems that affect the operation voltages is the bending of the membrane due to an internal stress gradient. To solve this problem, a thick and stiff membrane operated RF MEMS switch has been developed and is presented in this paper. This membrane consists of a flexible spring for an up-down actuation mode at low voltage and a pivot under the membrane for a seesaw mode on-off switch operation. This novel RF MEMS switch has been fabricated, and its RF characteristics measured. The minimum actuation voltage is approximately 10-12 V, the isolation approximately −50 dB, and the insertion loss is approximately −0.25 dB at 2 GHz, respectively.The bending range of the membrane has been measured by using an optical 3D profiler and the height is within 0.2 m across the 800 m length membrane. This bending range is uniform across all samples of an entire 4 in. wafer.

Design of RF MEMS Switch with High Stability Effect at the Low Actuation Voltage

Sensors & Transducers, 2009

MEMS switches are one of the most promising future micro-machined products that have attracted numerous research efforts in recent years. This paper presents an innovative design of RF MEMS switch, with low actuation voltage (VT), improved mechanical stability and reduced stiction. The proposed switch is fabricated on a coplanar waveguide (CPW) & actuated by electrostatic force. The mechanical and electrical performance of the switch has been tested. The simulation results show that the actuation voltage can be reduced by using serpentine folded spring, and improved mechanical stability and reduced stiction can be achieved by using a hydrophobic material with high Young's modulus as insulator in between top and bottom electrode. The measured pull-in voltage is 4 V.

Ultra low actuation voltage RF MEMS switch

Micro and Nano Systems Letters, 2015

In this brief a new low actuation voltage RF MEMS switch is presented which can be integrated and controlled with available CMOS technologies. Despite the advantages in the design of RF MEMS switches designing a low actuation voltage RF MEMS switch is still a challenging task. To overcome this problem, a small size RF MEMS switch utilizing a moving plate with multiple holes supported by a low spring constant beam is presented in this work. Experimental measurement results indicate pull-in voltage of 0.5 V and lift-off voltage of 0.3 V for 1.5 μm displacement. The measured return loss and insertion loss are better than −20 dB and −0.1 dB respectively for a frequency range extending from 3 kHz to 3GHz. The switching time is less than 0.22 ms when the switch is turned on with a CMOS buffer from TSMC-65 nm technology with 1.00 V supply voltage.

Fabrication and testing of RF-MEMS switches using PCB techniques

In this paper some design considerations and process development for fabricating RF MEMS switches on microwave laminate printed circuit boards (PCBs) are presented. PCB MEMS is a new technology, in which RF MEMS devices can be fabricated on any substrate, and can be monolithically integrated with other elements on the same substrate offering adaptability and reconfigurbility features to the communication systems. This work describes an alternative technique to improve manufacturing for fabrication of RF-MEMS switches on PCB. The integrated process uses metal as part of the sacrificial layer and the isotropic profile (undercut) of the wet etching to help on the bridge release. The mechanical characteristic and theory of operation of capacitive membrane switches is detailed. Pull-in voltage is in the range of 30-40 V. In the OFF state (up-position), the insertion loss is less than 0.3-0.4 dB up to 6 GHz. In the ON state (down-position), the isolation value is about 16 dB at 6 GHz and increases to 34 dB at 18 GHz.

DESIGN OF NON-UNIFORM SHAPED RF MEMS SWITCH

TJPRC, 2013

In this paper, we present aNovel Non-uniform shapedcantilever based DC contact RF MEMS switch. This switch can be employedfor various microwave applications in frequency range of DC-10GHz as it shows excellent RF characteristics. The design is optimized in the terms of electrostatic actuation mechanism, which included switch beam thickness, beam gap and materials. Also the due to its optimized shape and size of contact geometry and material ensures the high reliability, high isolation and very low insertion loss. The main features of our switch aresimplicity of structure, reliability of contact, excellent RF characteristics, low actuation voltage and excellent figure of merit. The pull-in voltage, contact force and S-parameters are analyzed with software such as Coventorware. Various Switching parameters areanalyzed for the performance of the switch in terms of switching speed and power consumption. The paper briefly outlines the Design of RF MEMS switches and also focuses on the research efforts that have gone into maturing the technology.

Low-Voltage High-Isolation DC-to-RF MEMS Switch Based on an S-shaped Film Actuator

IEEE Transactions on Electron Devices, 2004

This paper presents a new electrostatically actuated microelectromechanical series switch for switching dc to radio frequency (RF) signals. The device is based on a flexible S-shaped film moving between a top and a bottom electrode in touch-mode actuation. This concept, in contrast to most other microelectrochemical systems (MEMS) switches, allows a design with a low actuation voltage independent of the off-state gap height. This makes larger nominal switching contact areas for lower insertion loss possible, by obtaining high isolation in the off-state. The actuation voltages of the first prototype switches are 12 V to open, and 15.8 V to close the metal contact. The RF isolation with a gap distance of 14.2 m is better than 45 dB up to 2 GHz and 30 dB at 15 GHz despite a large nominal switching contact area of 3500 m 2 . Index Terms-Broadband switches, microwave switches, millimeter wave switches, RF MEMS.