How Does Fringing Field Capacitance Change with Conductor Shape and Size?

[Dekar]

Hi,

I am having two doubts about the fringing field capacitance.


1) In most of the formulae, the fringing correction for the capacitance is written per unit length. This is ok if the length is very large; and the width and gap between the two conductors are only comparable. But is there any formula, which takes into account the length effect as well? This would be three dimesional fringing field capacitance formula.

2) As the width of the capacitor decreases, the fringing correction is increased. Is there any way to calculate the fringing for a triangular shaped conductor, wherein the width at one end is equal to zero.

I would highly appreciate any help in this regards,

Dekar
India

 

[marcusl]

There is no analytical solution for general shapes--numerical solutions using an EM simulation code (HFSS, COMSOL, etc.) are your best bet.