Coupled Multiconductor Line (CPL)
The CPL multiconductor line model is in theory similar to the RLGC model, but without frequency dependent loss (neither skin effect nor frequency-dependent dielectric loss). Up to 8 coupled lines are supported in NGSPICE.
General form:
PXXXXXXX NI1 NI2...NIX GND1 NO1 NO2...NOX GND2 mname <LEN=LENGTH>
Example:
P1 in1 in2 0 b1 b2 0 PLINE
.model PLINE CPL length={Len}
+R=1 0 1
+L={L11} {L12} {L22}
+G=0 0 0
+C={C11} {C12} {C22}
.param Len=1 Rs=0
+ C11=9.143579E-11 C12=-9.78265E-12 C22=9.143578E-11
+ L11=3.83572E-7 L12=8.26253E-8 L22=3.83572E-7
ni1 ... nix are the nodes at port 1 with gnd1; no1 ... nox are the nodes at port 2 with gnd2. The optional instance parameter len is the length of the line and may be expressed in multiples of [(unit)]. Typically (unit) is given in meters. len will override the model parameter **length **for the specific instance only.
The CPL model takes a number of parameters:
Name
|
Parameter
|
Units/Type
|
Default
|
Example
|
R
|
resistance/length
|
$\frac{\Omega}{unit}$
|
0.0
|
0.2
|
L
|
inductance/length
|
$\frac{H}{unit}$
|
0.0
|
9.13e-9
|
G
|
conductance/length
|
$\frac{mhos}{unit}$
|
0.0
|
0.0
|
C
|
capacitance/length
|
$\frac{F}{unit}$
|
0.0
|
3.65e-12
|
LENGTH
|
length of line
|
unit
|
no default
|
1.0
|
All RLGC parameters are given in Maxwell matrix form. For the R and G matrices the diagonal elements must be specified, for L and C matrices the lower or upper triangular elements must specified. The parameter LENGTH is a scalar and is mandatory. For transient simulation only.