平行板电容器的尺寸效应

本文分别研究了平行圆形板和矩形板电容器的电容随其尺寸变化的规律.对于每种电容器,首先假设电荷在极板上均匀分布,由此能较简便地得出电容的近似值,然后用Ansoft软件作有限元仿真,得出更精确的数值.通过对比发现,用均匀带电近似得出的结果能够正确地反映电容随其尺寸变化的趋势,优于教科书中的平行板电容器公式;但其数值偏小,原...

The size effect of parallel-plate capacitor

It is investigated in this paper how the capacitance of parallel circular-plate and rectangular plate capacitors varies with the size,respectively.For each kind of capacitor,first it is assumed that charge is distributed uniformly on the plate,then approximate values of capacitance can be obtained conveniently,afterwards more accu rate values are obtained via finite element simulation using Ansoft.By comparison,it is discovered that results ob tained using the approximation of uniform charge distribution can reflect correctly the tendancy how the capacitance varies with the size,which is better than the capacitance formula of parallel-plate capacitor in textbooks;however,those values are smaller,since charge is not strictly distributed uniformly on the plate,but less in the middle and more on the edge.