AVS 50th International Symposium
    Microelectromechanical Systems (MEMS) Tuesday Sessions
       Session MM-TuA

Paper MM-TuA2
Fabrication and Characterization of a Capacitive Micromachined Shunt Switch

Tuesday, November 4, 2003, 2:20 pm, Room 320

Session: Fabrication and Characterization of MEMS Devices
Presenter: S.L. Firebaugh, United States Naval Academy
Authors: S.L. Firebaugh, United States Naval Academy
H.K. Charles, Jr., Johns Hopkins University
R.L. Edwards, Johns Hopkins University
A.C. Keeney, Johns Hopkins University
S.F. Wilderson, Johns Hopkins University
Correspondent: Click to Email
Microelectromechanical switches offer many advantages over solid-state devices, including greater linearity, increased isolation and lower insertion loss.@footnote 1-5@ One disadvantage of such switches is that they require high actuation voltages (20-100 V), leading to problems with dielectric charging and system integration. Furthermore, when reducing the actuation voltage one must consider the dependence of power handling capability on actuation voltage.@footnote 6@ This paper describes the design, fabrication and testing of a shunt switch@footnote 3,4@ based on a bridge suspended over a coplanar waveguide. When a sufficient DC voltage is applied the bridge pulls down towards the signal line, creating a high-frequency short circuit and causing the signal to reflect back towards the source, blocking transmission. The switch is used as a test vehicle to explore the effects of bridge shape on performance, as well as to investigate the limits of micromachined switches. A common problem for MEMS switch developers is obtaining equipment to test device characteristics such as power handling limits on a wafer probe station. In this work, standard microwave connectors and equipment are facilitated by a custom test fixture. The pull-in effect is studied in detail, as well as methods for switching the device while avoiding dielectric charging effects and maintaining reasonable power handling levels. @FootnoteText@ @footnote 1@ C.T.C. Nguyen et al., Proc. IEEE, vol. 86, no. 8, pp. 1756-1768, August 1998.@footnote 2@ J.J. Yao, J. Micromech. Microeng., vol. 10, pp. R9-R38, 2000.@footnote 3@ Z.J. Yao et al., IEEE J. Microelectromech. Syst., vol. 8, no. 2, pp. 129-134, 1999. @footnote 4@ J.B. Muldavin and G.M.Rebeiz, IEEE Trans. Microwave Theory and Tech., vol. 48, no. 6, pp. 1045-1052, June 2000.@footnote 5@ D. Hyman et al., Electron. Lett., vol. 35, no. 3, pp. 224-226, February 1999.@footnote 6@ B. Pillans et al., 2002 IEEE MTT-S Int. Microwave Symp. Dig., pp. 329-332.