I see only one way: make the VB script in HFSS or AutoCAD to drawing the parabola. But in any cases it will be only approximate parabola by polyline, however it's unimportant, because the simulation method cause much more error compared to this inaccuracy.
you can write a AutoLISP subroutine to draw a function in AutoCAD environment. If you decide to do this work, PM me to send you a useful AutoLISP subroutine.
Hey guys.
I know this is an old post, but in case somebody is interested, you can draw any kind of function y=f(x) in HFSS using the Maxwell interpreter.More specifically, you use the plotdata utility where you draw the function and then you export the line as an ansoft 2D object (sm2 file).