No abstract

Abstract-To design and validate accelerated life tests of RF MEMS capacitive switches, acceleration factors of charging effects in switch dielectric were quantitatively characterized. From measured charging and discharging transient currents at different temperatures and control voltages, densities and time constants of dielectric traps were extracted. A charging model was constructed to predict the amount of charge injected into the dielectric and the corresponding shift in actuation voltage under different acceleration factors such as temperature, peak voltage, duty factor, and frequency of the control waveform. Agreement was obtained between the model prediction and experimental data. It was found that temperature, peak voltage, and duty factor were critical acceleration factors for dielectric-charging effects whereas frequency had little effect on charging.

Abstract-Bipolar control-voltage waveforms, under which the control voltage alternates between positive and negative after each cycle, have been proposed to mitigate dielectric charging in electrostatically actuated RF microelectromechanical system capacitive switches. In this study, dielectric charging under bipolar waveforms is modeled and characterized quantitatively. In general, the experimental results agree with predictions based on the superposition of unipolar charging models that are extracted under positive and negative voltages, respectively. The basic assumptions for such a superposition model are examined in detail and validated experimentally. The current analysis indicates that, while bipolar waveforms can reduce charging, it is difficult to fine tune the waveforms to completely eliminate charging.

No abstract