Mechanical Modeling Issues in Optimization of Dynamic Behavior of RF MEMS Switches

This paper details few mechanical modeling and design issues of RF MEMS switches. We concentrate on an electrostatically actuated broad side series switch; surface micromachined with a crab leg membrane. The same results are extended to any complex structure. With available experimental data and fabrication results, we present the variation in dynamic performance and compliance of the switch with reference to few design issues, which we find are critical in deciding the dynamic behavior of the switch, without compromise on the RF characteristics. The optimization of pull in voltage, transient time and resonant frequency with regard to these critical design parameters are also presented.




References:
[1] DJ Bell, TJ Lu, NA Fleck, SM Spearing, MEMS actuators and sensors:
observations on their performance and selection for purpose - Journal of
Micromechanics and Microengineering, 2005, 15 S153-S164.
[2] J Jason Yao, RF MEMS from a device perspective, 200J. Micromech.
Microeng.1 R9-R385.
[3] E. R. Dept. of Electr. Eng., California Univ., Los Angeles, CA, RFMEMS
switches for reconfigurable integrated circuits, Brown,;
Microwave Theory and Techniques, IEEE Transactions on, Nov 1998,
Volume46,Issue11, Part 2, pp 1868-1880.
[4] Rebeiz M. Gabriel, RF MEMS Theory, Design and Technology,
HobokenJohn Wiely and Sons, 2003.
[5] Kim Jong-Man, Sanghyo Lee, Jung-Mu Kim, Chang-Wook Baek,
Youngwoo Kwon and Yong-Kweon Kim, A Mechanically reliable
digital-type single crystalline silicon (SCS) RF MEMS variable
capacitor, J. Micromechanics and Microengineering 15, pp.1854-1836,
2005.
[6] Jong-Man Kim et al, The SiOG-Based Single-Crystalline Silicon (SCS)
RF MEMS Switch With Uniform Characteristics, Journal Of
Microelectromechanical Systems, Vol. 13, No. 6, December 2004, IEEE.
[7] D. Peroulis ET AL, Electromechanical considerations in developing
low-voltage RF MEMS switches, IEEE Trans. Microwave Theory Tech.,
vol. 51, pp. 259270, Jan. 2003.
[8] M.S. Giridharr et al, Silicon-On-Glass RF MEMS switch for X band
applications Proceedings of ISSS 2008 International Conference on
Smart Materials, Structures and Systems, July 2008, Bangalore, India,
P35.
[9] Shishir Kumar and Rudra Pratap, Partitioning design space for linear
tuning of natural frequencies in planar dynamic MEMS structures,
Sensors and Actuators A: Physical, Vol 125, Issue 2, pp 304-312, 2006.
[10] R. Pratap, Some issues in mechanical design of MEMS transducers,
Proceedings of the ISSS-SPIE, Bangalore, India, December 12-14,
2001, pp. 733-739.
[11] S.-W. Chung and Y.-K. Kim, Design and fabrication of hidden spring
structure type micro SLM for phase and amplitude modulation Proc.
SPIE, vol. 3513, pp. 156-163, 1998.
[12] Suhas K, Modelling Studies and Fabrication Feasibility for Non-
Conventional RF MEMS Switches, KVPY IIT-B Report 2008,
(EB2007), Thesis 2008.
[13] J. B. Muldavin and G. M. Rebeiz, High-isolation CPW MEMS shunt
switches Modeling and design, IEEE Trans. Microwave Theory and
Tech., vol. 48, no. 6, pp. 10451056, 2000
[14] P G Steeneken et al, Dynamics and squeeze film gas damping of a
capacitive RF MEMS switch, 2005 J. Micromech. Microeng. 15 176-
184.