The optimization of mechanical harmonic modes of the 75 g balanced weight distribution capacitive accelerometer

摘要

The harmonic modes of movable proof-mass of differential capacitive accelerometer plays an important role in design. Another modes except main mode must be minimized to avoid uncertainty value of capacitance. In this paper, we tried to optimize the differential capacitive accelerometer using the variation of the length of finger attached at the proof mass. The length of finger varies from 40 /spl mu/m to 240 /spl mu/m with the variation of the width of proof-mass from 10 /spl mu/m to 40 /spl mu/m. The results have shown that the need to choose the length of finger for minimizing the effect of harmonic modes is as greater than 140 /spl mu/m assuming the external forces distributed in the interval of 0 to 1 MHz.