| 摘要 |
<p>Provided is a variable capacitance element capable of preventing an MEMS operation failure caused by charge-up without increasing a driving DC voltage. The variable capacitance element (1) is characterized as follows: A movable beam (3) including beam-side capacitance forming portions (3A to 3C) and a support portion (3D) is housed in a chassis. Lower driving electrodes (6A to 6C) and upper driving electrodes (7A to 7C) are provided facing the beam-side capacitance forming portions (3A to 3C). The space inside the chassis is set to a reduced-pressure atmosphere. When a driving DC voltage is applied, the beam-side capacitance forming portions (3A, 3B) are directly faced to the lower driving electrodes (6A, 6B) or the upper driving electrodes (7A, 7B), but the beam-side capacitance forming portion (3C) is not directly faced to the lower driving electrodes (6C) or the upper driving electrodes (7C). The transition from a state in which the driving DC voltage is applied to a state in which the driving DC voltage is not applied makes the displacement of the movable beam (3) overshoot the position in the state in which the driving DC voltage is not applied.</p> |
