equation based surface

I can't figure out how to use the equation based surface/curve features for drawing in hfss. Can somebody please give a simple example... any simple shape like a triangle or square will do, just trying to learn how to use it... Thanks

I'd be interested in examples as well.

Try this simple exercise.
Define parameter _t range: 1-10
x= Sin(_t)
y= Cos(_t)
z=0
See what you get :)
Play with _t range.

---------- Post added at 06:36 ---------- Previous post was at 05:49 ----------

Also try drawing exponential curve
use exp() function & define (_t) ( _t is variable)

Don't use z for a while, just draw 2D equation based curve for a while.

The unit circle :). Is there a way to specify step size for _t for equation based surfaces? I'm having issues plotting an equation based surface that varies exponentially in two planes (an exponentially flared horn).

I know, its dual or quad ridged horn antenna.
@ what frequency you are making broad band horn? Which application?

Its not easy if you try to implement exponential taper with equation based curve.
I will suggest following easy way:
Based on impedances fix the ridge thickness for regions of horn.
Use graph paper to decide co-ordinates & draw single points in HFSS.
Then connet them to form the complete curve.
And duplicate it to form structure.

I also tried using equation based curve, it works but you need to play with it.