What is the capacitance of a wire mesh parallel to a solid plane?

[m1985]

Hi Guys,

I seem to have forgotten most of EM, but I was hoping for some help on estimating the capacitance of a wire mesh/grid parallel to a solid plane. I'm guessing that it will follow the form of a simple parallel plate (with the appropriate area factor) if the geometries are such that the fringe fields can be neglected...

Thanks!

 

[berkeman]

That's how I would approach it as an initial approximation. If the mesh is pretty open, it might be better to approximate it as a combination of a bunch of wires over the plane.

 

[m1985]

Thanks... that sounds about right. I'm having a hard time visualizing the E-fields when many wires are placed close together above the ground plane... I'm thinking that the total capacitance isn't simply the summation of the capacitance of each individual wire to the plane...
Thanks!

 

[berkeman]

Thanks... that sounds about right. I'm having a hard time visualizing the E-fields when many wires are placed close together above the ground plane... I'm thinking that the total capacitance isn't simply the summation of the capacitance of each individual wire to the plane...
Thanks!

I'm wondering about that too, but if the wires are at the same potential... You can sketch the E-field and resulting equipotential surfaces for a single wire, and then see what it looks like when you parallel up some wires at the same potential...