[SI-LIST] Defining stackup in HSPICE Field Solver

Dear SI List,
I am trying to use the HSPICE internal field solver for a microstrip
line.
Here's my stackup:
layer 1 - top
layer 2 - gnd1
layer 3 - vcc1
layer 4 - vcc2
layer 5 - gnd2
layer 6 - bottom

In XTK, I can list out the layers as they are and get the right
impedence (100 ohms). But to do this in the field solver in HSPICE?

>From the manual it seems I only define a ground layer and then a signal

layer?

So I tried this:

********** W element tline definition**********
*
* Define the board material
* Losstangent = tan (delta) LOSSTANGENT=0.020
.MATERIAL diel1_fr4 DIELECTRIC ER=4.2
.MATERIAL diel2_fr4 DIELECTRIC ER=3.8
.MATERIAL copper METAL CONDUCTIVITY=5.8e+07

* Define the cross section of the trace as a rectangle
* 1.0 oz copper (usually has height of 1mil), 8 mil wide
.SHAPE rect RECTANGLE WIDTH=8mil, HEIGHT=1.37mil

* Define the layer stackup
* Layer = (material name, thickness)
.LAYERSTACK microstrip_one_100
+ LAYER=(copper,1mil)  * ideal ground plane
+ LAYER=(diel1_fr4,21mil) * signal layer

.FSOPTIONS opt1 PRINTDATA=yes
+ ComputeRo=yes ComputeRs=yes ComputeGo=Yes ComputeGd=yes
+ ACCURACY = HIGH

.MODEL micro100 W MODELTYPE=Fieldsolver,
+LAYERSTACK=microstrip_one_100 FSOPTIONS=opt1
+CONDUCTOR= (MATERIAL=copper, SHAPE=rect, ORIGIN= (0, 21mil))

******  End of the W element definition
*****************************************************

Is this the correct way to define the equivalent stackup? And what do I
choose as my origin?
Accroding to the output, I get an L value of 368nH, which is not right.

Thanks to anyone who can help me out -

Tim




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