Problem simulating balun with antenna in HFSS

Hello everyone,

I've modeled a planar antenna in HFSS (curtain quad). It looks somewhat like this, but created with strips etched on a substrate: ../imgqa/eboard/EM/EM-qlj4somlsfo.jpg. The antenna is created on 30 mil thick 6002, backed by 1" foam, and there is a reflector behind this. The feed is in the center and the input impedance is 200 ohms.

Naturally, this requires a balun. I designed a balun with an exponential taper to transform 50 ohms unbalanced to a 200 ohm balanced line. The idea is to fabricate the curtain quad antenna and balun on separate PCBs. A slit will then be cut through the reflector and substrate to allow one to solder the balanced end of the balun to the feed of the curtain quad antenna.

I've included attachments of images showing what I'm trying to accomplish.

The problem I'm having is how to realize the simulation of the entire structure since the airbox from the balun runs into the substrate for the antenna. I can simulate the balun by itself, but don't know how to excite the curtain quad by itself in HFSS without a balun. If it is as simple as extending the feed and using a waveport, I can do that. Ideally, I'd like to simulate the entire structure though.

Any ideas are welcome as to how to accomplish this are welcomed!