Design And Analysis Of Comb Capacitive Accelerometer

The research works are made with scientific projects. This thesis introduces thebackground and development of MEMS inertial sensors, discussion of MEMSmechanical structure design theory and dynamics of electromechanical couplinganalysis method, the thesis is divided into two main parts:The first part describes the structural design and working principle ofmicro-accelerations, including the electrostatic actuation principle of capacitive combstructures, a detailed derivation of the various functional units and the parameters ofthe model of capacitive micromachined sensor devices establish support beam model,detection capacitance model, electrostatic actuation model, detection structure andprinciple of differential capacitance interface schematic. Before micro-accelerationsensor analysis of the structure, it presents design damping and noise analysis, whichfocuses on the theory of gas damping.The second part is that it makes use of MEMS dedicated software to complete theestablishment of the comb capacitive micromachined accelerometer principle levelsystem model, and to give the results of its modal simulation analysis, dynamicsimulation analysis, and differential capacitance output simulation analysis. Thedisplacement of sensing mass is calculated at low-g acceleration action, to show a goodoutput linearity of acceleration detection. Therefore, the circuit design can be based onspecification of performance and technical parameters for subsequent readout circuitdesign.The third part gives analysis of readout circuit, based on the model of mechanicalstructure, and proposes some part of circuit design.