A study on electrostatic tuning of resonant frequency for SOI-MEMS resonators

Electrostatic tuning characteristics of the electrostatic resonators fabricated using SOI-MEMS technology with various configurations and voltage bias conditions were systematically studied using the FEM simulator. The basic structures of the resonators consist of a lmmxlram proof mass and four 200um-long, 3um-wide beams, whose thicknesses are lOum, resulting in the resonant frequencies of the fundamental resonant mode without applied voltages which were about 5kHz. The resonant frequencies of the resonators with parallel-plate electrodes decreased quadratically with the applied voltage, while those of the resonators with comb electrodes gave no significant change. When the influence of the substrate was taken into consideration, the resonant frequency change by the applied voltage was reduced by several percents. © 2010 The Institute of Electrical Engineers of Japan.