I am new to Feko and Antenna Design in general. I am trying to model a simple turnstile antenna for a 1-Unit CubeSat, which then I am going to build using tape-measure (as conductors of turnstile antenna) and a PCB in the middle for feed circuit.
here is a link where you can learn more about CubeSats (if needed): https://www.isispace.nl/cubesats/
When I model the antenna in Feko, there's always at least one dielectric region that has negative power loss in *.out file.
For example, when I model the antenna without metallic body of CubeSat, image 1 shows the negative power loss in *.out file and image 2 shows the far field pattern.
When I add the metallic body, images 3 and 4 show the results.
I have also attached my CAD files.
Can you tell me why this negative power loss happens and how can I fix it?
And also, what other ways can I use to validate my results? Since, radiation pattern in image 4 doesn't seem correct to me
Thank you very much,