On the investigation of a reliable actuation control method for ohmic RF MEMS switches

Abstract

Efficient control of RF MEMS switches is a very important issue as it is correlated to main failure mechanisms/modes such as the impact force and bouncing phenomena which degrade their dynamic performance and longevity. This paper presents the control of a specific ohmic RF MEMS switches under three different actuation modes, a tailored pulse optimization method based on Taguchi's technique (voltage mode actuation control), resistive damping (charge mode actuation control) and finally the Hybrid actuation mode, which is a combination of the tailored pulse, the resistive damping and Taguchi's optimization technique. Coventorware simulations indicate that under optimized Tailored pulse and Hybrid actuation modes, the impact velocity is reduced by around 90%, the initial impact force by around 75% and the maximum bouncing displacement during the release phase by around 95%, while the switching speed is increased by around 20% compared with the step pulse control mode. The resistive damping control mode is inappropriate for this type of switch and only partial improvement during the pull-down phase has been achieved. 2Finally, a comparison between Hybrid and optimized tailored modes shows that Hybrid actuation mode excels with better switching characteristics and most importantly offers immunity to manufacturing and operation tolerances.

Control of Bouncing in MEMS Switches Using Double Electrodes

“…On the other hand, Do et al [3] developed an analytical method based on energy consideration for selecting the parameters of the dual pulse wave. Spasos and Nilavalan [11] presented description of two techniques to control bouncing: the charge control (resistive damping) and the voltage control. Voltage control is based on an open loop statistical method to control bouncing called the Taguchi's optimization technique.…”

A review of micro-contact physics for microelectromechanical systems (MEMS) metal contact switches

“…13,[94][95][96][97][98][99][100][101][102] In MEMS, switch designers have focused on suppressing or 'engineering away' contact bounce using mechanical switch designs or novel actuation signals that aim for near zero impact velocity of the electric contacts. [96][97][98][99][100][101][102] Peschot et al however, performed experiments to better explain contact bounce at the nanometer scale. 103 Using an AFM and a nano-indenter, the researchers controlled micro-contact make and break operations at low values of electrode velocity (few tens of nm s −1 ).…”

Design, Analysis and Comparison of Various MEMS Switches for Reconfigurable Planar Antenna

“…The reaction force (F) balance the generated electrostatic force produced in beam structure. At two-third air gap, the switch beam becomes unstable and results in breakdown at the lower transmission line in down-state position [29][30][31][32][33][34]. The pull-in voltage be influenced by the value spring constant of beam shape, gap and electrode area [1,28].…”

“…Further, microstrip transmission may be considered as a two wire line and is further viewed the most extensively used as a planar microstrip transmission line [29][30][31]. One side of the design is free to access for mounting on the hymite or other packaged devices and further geometrical construction lends itself well to printed circuit board patterning methods to define the complete circuit.…”

“…Recently, MEMS on/off switches have shown very good RF characteristics, including smaller size, lower insertion loss in on state, almost zero power consumption, higher isolation in off state, extreme lower intermodulation distortion and weight [4,5,29]. The switch's capability to achieve well upto 50 GHz is a noteworthy leap forward over solid-state and mechanical RF switches [6,30]. The RF MEMS switches are applied on various shapes and geometry of microstrip antennas like planar inverted F-shape (PIFA), E-shape, S-shape, spiral, fractal and many more to achieve different applications.…”