Curtain quad on substrate - what type of port to use in FEKO?

Hello everyone,

I have a planar antenna (curtain quad) that I'm simulating in FEKO, similar to this but etched: **broken link removed**. The antenna is created from strips of metal on a thin substrate (no ground plane). The thin substrate is placed over a 1" thick foam layer, which is backed with a reflector. The feed point is in the center of the antenna, where this will be a small gap to excite the antenna.

What is the best way to feed this structure in FEKO? I'd use a short wire with a wire port in the center, but FEKO gives me an error (I'm using 5.4) since the wire is placed at the boundary between two media (the substrate and vacuum). Will an edge port work? I'm stumped.

Note that eventually, I'd like the s-parameters from a microstrip tapered balun I'm designing in HFSS and import them into FEKO. If the ports can be set up such that this is possible, that would be fantastic. In real life, the microstrip tapered balun will be on its own PCB and connected and soldered normal to the antenna array. I can upload an image if this isn't clear.

I'm still racking my brain over this. Any ideas?

On another note, if I want to simulate a microstrip tapered balun in FEKO, how should I set up the ports? With HFSS, I'd just use a waveport and specify 1 mode on the unbalanced end, and 2 modes on the balanced end.