How to construct and excite a dipole made from a cylinder

Altair Forum User

I have to model a dipole using cylinders (can't use segments since the dipole is very 'fat'), but I don't know how to create the excitation for such a dipole. Can someone help?

JIF

A dipole antenna made from a cylinder (and thus meshed into triangles) presents two common problems to users: Firstly how to excite the dipole and secondly how to create a mesh that follows the curvature of the dipole but which is not overly discretised. This how-to gives a step-by-step guide to creating this antenna.

Step by step

1. Create a cylinder with length equal to the total length of the dipole antenna.
2. Split the cylinder in half on the XY plane (assuming the cylinder was created on the Z-axis).
3. Union the two halves.
4. Create a cutplane in the YZ or XZ plane.
5. Delete the Face inside the cylinder on the XY plane.
6. On the Source/Load tab click on Edge port - for the Positive faces click in the 3D view on the top half of the cylinder (this should populate the Positive faces box. Do the same for Negative faces. Then click Create to complete the port.
7. Create a voltage source.

 

An alternative to the edge port would be to insert a small separation between the dipole halves and create a short wire between the halves. Then a wire port can be used.

Meshing:

Since the geometry is curved, the mesh will have to represent the curvature. The advanced tab of the Create Mesh dialog can be used to adjust the curved geometry approximation settings. Alternatively, for MoM solutions users can enable Higher Order Basis Functions. CADFEKO will then mesh curved triangles.

Unable to find an attachment - read this blog