Feed Connection Issue in Monocone Antenna – Current Not Propagating Through Cone Body

Sungkyun_Lim

Dear Altair Support Team,

I am designing a monocone antenna in FEKO using a surface-based cone structure with a parabolic top cap, where the feed is implemented via a vertical wire connected from the cone tip to ground. While the geometry appears correct and the simulation runs, I am encountering a significant issue: current does not propagate through the cone body. Despite the wire feed connection, the cone surface does not behave as an electrically continuous path, and no meaningful current distribution or radiation is observed across the cone. I suspect the problem arises from the interface between the wire and the surface-based cone structure, which may not be electrically connected in the simulation. I would like to know how to properly model the feed connection so that current can flow across the entire cone surface. Is there a recommended method in FEKO to ensure electrical continuity between wire elements and surface geometries? Any guidance on correctly establishing this junction and resolving the feed issue would be greatly appreciated. I attached the editfeko, Postfeko file and also feed connection problem image.

MultiHelix_Cone.fek

MultiHelix_Cone_Curved.pre

feed coonection.png

Zeina

Hi @Sungkyun_Lim ,

Mesh continuity in Feko is guaranteed by Union-ing all the geometry parts that touch or intersect.

From the shot you shared I see that the current induced by the voltage source is very high at that position (kA), and this might be resulting in a display range that is not allowing you to view the lower values of the currents on the the surface of the cone and ground plane. You can try to adjust the scale range by limiting the max value for the linear scale, or by controlling the active range for dB range.

Here is a current display example of a monocone antenna run at 1GHz, where in the display to the right I have limited the max value to 0.1A, instead of 2.5A to be able to see better the lower current values:

This scale adjustment can be done from the Display > Legends > Individual Ranges menu.

Running the .pre file you have shared is giving errors so I could not run it.