Design and fabrication of multi-dimensional RF MEMS variable capacitors [electronic resource] / by Hariharasudhan T. Kannan.
ABSTRACT: In this work, a multi dimensional RF MEMS variable capacitor that utilizes electrostatic actuation is designed and fabricated on a 425um thick silicon substrate. Electrostatic actuation is preferred over other actuation mechanisms due to low power consumption. The RF MEMS variable capacitor is designed in a CPW topology, with multiple beams supported (1 - 7 beams) on a single pedestal. The varactors are fabricated using surface micromachining techniques. A 1um thick silicon monoxide (Er - 6) is used as a dielectric layer for the varactor. The movable membrane is suspended on a 2.5um thick electroplated gold pedestal. The capacitance between the membrane and the bottom electrode increases as the bias voltage between the membrane and the bottom electrode is increased, eventually causing the membrane to snap down at the actuation voltage. For the varactors designed herein, the actuation voltage is approximately 30 - 90V.
School:University of South Florida
School Location:USA - Florida
Source Type:Master's Thesis
Keywords:single pedestal cantilever beams electrostatic actuation capacitance ratio quality factor dissertations academic usf electrical engineering masters
Date of Publication:01/01/2003