الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
In recent years, the field of Microelectromechanical systems (MEMS) has grown rapidly and has entered into many applications. Electrostatically actuated membranes or beams have been widely used and studied by the MEMS community. Electrostatically actuated devices form a broad class of MEMS devices due to their simplicity as they require few mechanical components, and small voltage levels for actuation. Electrostatically actuated microbeams are used in many MEMS devices such as capacitive MEMS switches and resonant sensors.
Radio Frequency (RF) MEMS switch technology has been introduced during the last 10-15 years as a viable alternative with superior RF performance over traditional semiconductor switches. Low-cost MEMS switches are prime candidates to replace the conventional GaAs Field Effect Transistor (FET) and p-i-n diode switches in RF and microwave commW1ication systems, mainly due to their low insertion loss, good isolation. linear characteristic and low power consumption.
This thesis presents electromechanical simulation and optimization of cantilever type MEMS switches. The modeJ1ing approach is based on nodal anaJysis to solve coupled non-linear differential equations that describe the electromechanicaJ system using a Matlab toolbox for MEMS (SUGAR). The switching voltage of the mentioned construction for MEMS switches is determined and analysed at different geometrical parameters. The results show that the beam length, width, thickness and electrostatic gap dimensions, affect significantly on reducing the switching voltage. These parameters are optimized to achieve a minimum threshold voltage and maximum switching ttequency using genetic algorithm.
The optimization process indicates that the switch can operate with minimum threshold voltage of 7.2 V with switching frequency of 453 MHz. Also, the switch can give a maximum switching frequency of2.83 GHz at 12.75 threshold voltage.