Thanks for the info.
I does seem that you can remove the gnd layer or at least define it as air.
I have ran several models copied from know sources and compared the results
to the original. The results do match.
Thanks one more time.
lance

"Mark" wrote in message
...
On Sun, 25 Apr 2004 13:11:12 -0700, "Lance" wrote:

I looking to layout a loop or spiral antenna using ensemble sv.
Has anybody done this? I have completed some designs with the software
based
on some application notes. My problem is I having difficulty matching 50
ohm
impedance and a VSWR of less than 1.5.
If someone has done this I would appreciate some advice.
Thanks



Closed loops in Ensemble are interpreted as solid areas. You would
need to define an air layer to remove the "middle" of the loop. I'm
not sure you can do this with the SV version because the number of
layers is limited. You may want to try disabling the ground layer and
drawing an object on the dielectric layer to see if you can "fool" the
program into making this work.

Ansoft shows examples in their literature of what's required to
properly represent a microstrip quadrature hybrid network by drawing
an air "object" in the middle of the hybrid.

Spirals (that do not close on themselves) may simulate properly,
assuming you have enough triangles to represent the design.

Good luck.

Mark
Mark