[SI-LIST] modelling of wire as w-element transmission line
- From: Jayanta Choudhury <jxc9551@xxxxxxxxxxxxxxxxxx>
- To: si-list@xxxxxxxxxxxxx
- Date: Tue, 25 Jun 2002 11:56:10 -0500 (CDT)
Hi,
I want to model a wire or metal, used in the metal layers of semi conductor
substrate preferably CMOS or GaAs high-speed circuits, in hspice 2000.4. The
purpose to study signal corruption and distortion during the signal
propagation
thru the interconnects. I am using the W-element transmission line model for
this and FSModel with SHAPE of metal as "strip". I want to see the waveforms in
the situation described below.
1. Two transmission lines with multiple conductor passing accross each other.
2. Two transmission lines are at different heights
3. Both of them has same reference ground for near-end and far-end terminals,
which is the bottom of the substrate.
the top view is some what similar to what is shown below.
| |
--------------|-------|---------------------
| |
--------------|-------|---------------------
| |
| |
If I model the longer lines with z-axix along their length, y-axis along their
height and width along the x-axis I cannot model two conductors of the
transmission line with shorter conductors. I can have only one conductor of
that
by having its width eqaul to the size of the actual length of the shorter
conductor in strip SHAPE statement and length equal to actual width. But the
spice file keeps running in an infinite loop.
The spice file is attached.
If any one has any clue to this please help me.
Thank you.
Jayanta Choudhury
-- Attached file included as plaintext by Ecartis --
-- File: across_lines.spice
-- Desc: across_lines.spice
*example. for observing two transmission lines lengths spreading accross each
other
.OPTION scale=0.1u
.OPTION POST
**a piece wise linear input waveform is used to model a step input
v1 in1 GND pwl 5n 0v 5.06n sp, 14.94n sp, 15.0n 0v
**V1 in1 gnd PULSE (0 5 2NS 0NS 0NS 50NS 100NS)
**V1 in1 gnd SIN (0 5 1MEG)
**W type transmission line state ment with driver side in1 and gnd and reciever
side
** out1 and ground, Field Solver(FSmodel) model is defined below, number of
conductors
** is N=2 length of the strip is l=25*scale(0.1um)
W1 out00 out01 gnd in00 in01 gnd FSmodel=mymodel1 N=2 l=25000
W2 out10 gnd in10 gnd FSmodel=mymodel2 N=1 l=500
**Output Capacitance
C1 out00 gnd 10fF
c2 out01 gnd 10fF
C3 out10 gnd 10fF
.PARAM sp=3.3v
**Model for solving equations and calculating RLGC values and writing them in
RLGC
**file specified by OUTPUTFORMAT, RLGCFILE is the file name ORIGIN is the
co-ordinates
**of strip MATERIAL is the metal for the conductor
.MODEL mymodel1 W MODELTYPE=FieldSolver LAYERSTACK=mystack FSOPTIONS=myoption
+ RLGCFILE=test4.rlgc OUTPUTFORMAT=RLGCFILE CONDUCTOR=( SHAPE=myshape1,
+ ORIGIN=(1000, 3000), MATERIAL=mymetal), ( SHAPE=myshape2, ORIGIN=(1050,
3000), MATERIAL=mymetal)
**Model for solving equations and calculating RLGC values and writing them in
RLGC
**file specified by OUTPUTFORMAT, RLGCFILE is the file name ORIGIN is the
co-ordinates
**of strip MATERIAL is the metal for the conductor
.MODEL mymodel2 W MODELTYPE=FieldSolver LAYERSTACK=mystack FSOPTIONS=myoption
+ RLGCFILE=test5.rlgc OUTPUTFORMAT=RLGCFILE CONDUCTOR=( SHAPE=myshape2,
+ ORIGIN=(0, 5000), MATERIAL=mymetal)
**mymetal has the characteristics of copper
.MATERIAL mymetal METAL CONDUCTIVITY=57.6meg
**dielectric has the characteristic of some example dielectric from manual
.MATERIAL mydiel DIELECTRIC LOSSTANGENT=1.2e-3
**Shape is Strip with width 1 micron and N=100 is number of discretization
.SHAPE myshape1 STRIP WIDTH=500 N=100
.SHAPE myshape2 STRIP WIDTH=25000 N=5000
**LAYERSTACK is the stack of dielectric or metal layers associated with
transmission
**line, here it is a stack of default type metal named PEC and a dielectric
** specified by Material is background and thickness of PEC is 5um
.LAYERSTACK mystack BACKGROUND=mydiel LAYER=(PEC, 5), LAYER=(mydiel, 5095)
**Options for Field Solver model is defined GRIDFACTOR, which is multipled with
**number of discretization specified in shape, PRINTDATA to print the datas
**COMPUTEGD to calculate the conductance matrix Gd for rotation of dipoles under
**the influence of alternating electric field, COMPUTERS computes skin effect
**Resistance matrix Rs
.FSOPTIONS myoption ACCURACY=HIGH GRIDFACTOR=1 PRINTDATA=YES COMPUTEGD=YES
+ COMPUTERS=YES
.TRAN 0.01n 1000n
.end
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