How to copute the RCS of an infinite long dielectric cylinder?

Question

Hi, I would like to know how to compute the 2D RCS (scattering width) of an infinitely long dielectric cylinder in FEKO. The official example for an infinitely long PEC cylinder removes the top and bottom faces before applying a 1D Periodic Boundary Condition. Should the same procedure be followed for a dielectric cylinder? If the top and bottom faces are removed, only the cylindrical side surface remains, and I can no longer assign a dielectric material to the cylinder. What is the recommended way to model an infinitely long dielectric cylinder in FEKO?

Jaehoon · Accepted Answer

Hello @XH2026

Here are the answers to your questions.

1.Should the same procedure be followed for a dielectric cylinder?

→ Yes. You can just change the material property to a dielectric material and apply SEP for the dielectric.

2. If the top and bottom faces are removed, only the cylindrical side surface remains, and I can no longer assign a dielectric material to the cylinder. What is the recommended way to model an infinitely long dielectric cylinder in FEKO?

→ It there is no top and bottom faces, it will be not a normal cylindric dielectric body, but a hollow dielectric cylinder. Then, how to model the hollow dielectric cylinder depends on the thickness of the dielectric part. If the thickness is thin, you can use Layered Dielectric.

If the thickness is thick, you can subtract an inner cylinder from the whole cylinder and apply the dielectric medium for the remaining part (region, SEP), as shown below.

And, 1D PBC (Periodic Boundary Condition) will be still useful to model the infinite cylinder regardless of the existence of the top and bottom faces.

If the answer above is not enough, please share your Feko model.

Best regards,

Jaehoon