Title :
Spontaneous oscillation due to charging effect in MEMS RF switches
Author :
Chen, Y. -C ; Ishida, T. ; Toshiyoshi, H. ; Chen, R. ; Fujita, H.
Author_Institution :
PME, Nat. Tsing Hua Univ., Hsinchu, Taiwan
Abstract :
A spontaneous oscillation due to charging effect in an RF MEMS switch was investigated. When an RF MEMS switch opens from its contact mode, a nano-scale gap is formed and the charges accumulate between the movable and fixed electrodes, which cause a strong attractive force in the gap. The attractive force draws the electrodes to contact each other again, thus the charges are neutralized. As the charges are cyclically accumulated and dissipated, the intermittent excessive electrostatic force is generated, leading to the repeated pull-in/contact/pull-out motions at tens of kHz. The lifetime of MEMS switches was reduced because the electrode surfaces were degraded after cyclical excessive contacts by the oscillations. The spontaneous oscillation was analyzed theoretically by the extended Qucs model. The experiments were performed to validate the investigated effect of the spontaneous oscillation.
Keywords :
electrical contacts; electrodes; electrostatics; microswitches; oscillations; MEMS RF switch; charging effect; cyclical excessive contact; electrode surface; extended Qucs model; intermittent excessive electrostatic force; nanoscale gap; pull-in-contact-pull-out motion; spontaneous oscillation; Contacts; Electrodes; Electrostatics; Force; Integrated circuit modeling; Oscillators; Radio frequency; MEMS-opposing-tip device; Qucs equivalent circuit model; RF MEMS switch; Spontaneous oscillation;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems Conference (TRANSDUCERS), 2011 16th International
Conference_Location :
Beijing
Print_ISBN :
978-1-4577-0157-3
DOI :
10.1109/TRANSDUCERS.2011.5969675