Finite element simulation and capacitive analysis on coupling capacitor using complex variable method of quasi-electrostatic field

Aimed at the accurate measurement of high-speed motion targets in Active Protection System, a capacitive analytic approach, based on complex variable method, was proposed for the planar capacitive coupling sensor working in quasi-electrostatic field. This approach, applying to analyze symmetry model, needs little calculation and more accurate. It directly reflects the relation between the capacitance and electrode structural parameters. The results show that increasing electrode diameter has a major influence on improving the sensitivity, and electrode spacing has no significant effect. Proper electrode spacing needs to be selected in order to meet the detection range and distance. A good agreement was obtained by the comparison of the theoretical results, experiment results and simulation results. These results contribute the experiment schemes improvement and optimization in the future work.