Electronic device including multiple capacitance value mems capacitor and associated methods

Abstract

An electronic device, such as a filter or phase shifter, for example, includes a substrate, and a MEMS capacitor on the substrate and having a plurality of selectable capacitance values. The MEMS capacitor preferably includes a lower capacitor electrode on the substrate, and a movable bridge including end portions connected to the substrate laterally adjacent the lower capacitor electrode. The movable bridge may also include a conductive medial portion between the end portions defining an upper capacitor electrode suspended above the lower capacitor electrode and being movable between an upper position and a lower position by an electrostatic force generated between the capacitor electrodes. The upper and lower positions provide respective low and high selectable capacitance values. Moreover, the movable bridge may further include at least one travel limiting portion between the end portions for engaging adjacent substrate portions to keep the upper capacitor electrode in a predetermined spaced relation from the lower capacitor electrode when in the lower position. This travel limiting feature of the MEMS capacitor is relatively easy to fabricate and avoids the sticking or stiction problem of some other types of MEMS capacitors.