DYNAMIC CHARACTERISTICS AND VIBRATIONAL RESPONSE OF A CAPACITIVE MICRO-PHASE SHIFTER

The objective of this paper is to control the phase shifting by applying a bias DC voltage and changing the mechanical characteristics in electrostatically-actuated micro-beams. This problem can be more useful in the design of micro-phase shifters, which has not generally been investigated their mechanical behavior. By presenting a mathematical modeling, Galerkin-based step by step linearization method (SSLM) and Galerkin-based reduced order model have been used to solve the governing static and dynamic equations, respectively. The equilibrium positions or fixed pints of the system have been determined and the calculated static and dynamic pull-in parameters have been validated by previous experimental and theoretical results and a good agreement has been achieved. The frequency response of the system has been studied and illustrated that changing applied bias DC voltage affects the resonance frequency and maximum amplitude of the system vibrations. Then, phase diagram of the system for various damping ratio and excitation frequencies has been gained. It has been shown that by changing the bias DC voltage applied on the electrostatically-actuated micro-beam, which can be used as a varactor in phase shifter circuit, the stiffness of the micro-beam changes and consequently the phase shifting can be controlled. Finally, effect of the geometrical and mechanical properties of the micro-beam on the value of the phase shifting has been studied. © 2011 IAU, Arak Branch. All rights reserved.

[1]  S. Senturia,et al.  M-TEST: A test chip for MEMS material property measurement using electrostatically actuated test structures , 1997 .

[2]  S. D. Senturia,et al.  Generating efficient dynamical models for microelectromechanical systems from a few finite-element simulation runs , 1999 .

[3]  W. K. Alverson,et al.  A Reciprocal TEM Latching Ferrite Phase Shifter , 1966 .

[4]  Ghader Rezazadeh,et al.  Mechanical behavior of a circular micro plate subjected to uniform hydrostatic and non-uniform electrostatic pressure , 2007 .

[5]  C. Andricos,et al.  C-band 6-bit GaAs monolithic phase shifter , 1985, IEEE Transactions on Electron Devices.

[6]  Ali H. Nayfeh,et al.  Characterization of the mechanical behavior of an electrically actuated microbeam , 2002 .

[7]  Ghader Rezazadeh,et al.  Dynamic characteristics and forced response of an electrostatically-actuated microbeam subjected to fluid loading , 2009 .

[8]  Ali H. Nayfeh,et al.  A reduced-order model for electrically actuated microbeam-based MEMS , 2003 .

[9]  Gabriel M. Rebeiz,et al.  Distributed MEMS true-time delay phase shifters and wide-band switches , 1998 .

[10]  Gabriel M. Rebeiz,et al.  Very low-loss distributed X-band and Ka-band MEMS phase shifters using metal-air-metal capacitors , 2003 .

[11]  Mohammad I Younis,et al.  Investigation of the response of microstructures under the combined effect of mechanical shock and electrostatic forces , 2006, Journal of micromechanics and microengineering : structures, devices, and systems.

[12]  W. Grabinski,et al.  Electrical modeling of a pressure sensor MOSFET , 2001 .

[13]  R. V. Garver.  Broadband Diode Phase Shifters , 1971 .

[14]  G. Rezazadeh,et al.  Mechanical Behavior of an Electrostatically-Actuated Microbeam under Mechanical Shock , 2009 .

[15]  S. Senturia.  Microsystem Design , 2000 .

[16]  G.M. Rebeiz,et al.  2-bit MEMS distributed X-band phase shifters , 2000, IEEE Microwave and Guided Wave Letters.

[17]  Charles L. Goldsmith,et al.  X-band RF MEMS phase shifters for phased array applications , 1999 .

[18]  G. Rezazadeh,et al.  Static and dynamic stabilities of a microbeam actuated by a piezoelectric voltage , 2009 .

[19]  R. A. Pucel,et al.  Monolithic Dual-Gate GaAs FET Digital Phase Shifter , 1982 .

[20]  R. V. Garver,et al.  Broad-Band Diode Phase Shifters , 1972 .

[21]  B. Pillans,et al.  Ka-band RF MEMS phase shifters , 1999 .

[22]  Ali H. Nayfeh,et al.  Dynamics of MEMS resonators under superharmonic and subharmonic excitations , 2005 .