RF-MEMS voltage tunable capacitor using electrostatic forces

In this paper, we have proposed a fabrication method of a RF-MEMS voltage tunable capacitor using Au-electroplating technique, which has one movable parallel plate with various structure of beams. We applied an electrostatic method and electroplating technique. Electroplating technique is used to fabricate various geometric structures in the surface micromachining technology. In consequence, compared with conventional structures, the theoretical tuning range, Cmax/Cmin, can be widely ranged at the applied bias voltages. Capacitance of the designed voltage tunable capacitor has from 1.0pF to 1.48pF as the applied bias voltage from 0.5V to 2.52V. The effective area and the distance of the capacitor plates are 650x650mum(2) 2 and 3mum for IpF, respectively.