RF microelectromechanical systems device

An RF-MEMS device comprising:

• a substrate;
• an RF signal-conducting unit arranged on the substrate;
• a movable element arranged above the substrate with a space therebetween and facing at least a portion of the RF signal-conducting unit with a space therebetween;
• a movable electrode arranged on the movable element and facing at least a portion of the RF signal-conducting unit;
• an upper member facing at least a portion of a top surface of the movable element with a space therebetween;
• and
• a fixed electrode arranged on the upper member so as to face at least a portion of the movable element;
• wherein
• the movable element includes a high-resistivity semiconductor defining an insulator for an RF signal and defining an electrode for a low-frequency signal and a DC signal, the fixed electrode and the movable element are arranged to function together and define a movable element displacing unit for displacing the movable element towards the fixed electrode by electrostatic attraction caused by a DC voltage applied between the fixed electrode and the movable element, the movable element displacing unit displaces the movable element towards or away from the substrate by the electrostatic attraction, and the displacement of the movable element caused by the movable element displacing unit changes the space between the RF signal-conducting unit and the movable electrode so as to vary the capacitance between the RF signal-conducting unit and the movable electrode.