The multidec Utility: Coupled Lossy Transmission Lines

The standalone program multidec produces a subcircuit for multiconductor lossy transmission lines in terms of uncoupled (single) simple lossy lines. This decomposition is valid only if the following hold:

1. The electrical parameters (R, G, Cs, Cm, Ls, Lm) of all wires are identical and independent of frequency.
2. Each line is coupled only to its (maximum 2) nearest neighbors.

The subcircuit is sent to the standard output and is intended to be included in an input file.

The command-line options for multidec are as follows:

-l< self-inductance Ls>
-c< self-capacitance Cs>
-r< series-resistance R>
-g< parallel-conductance G>
-k< coeff-of-inductive-coupling K>
-x< mutual-capacitance Cm>
-o< subckt-name>
-n< number-of-conductors>
-L< length>

The inductive coupling coefficient K is the ratio of Lm to Ls. Values for -l, -c, -o, -n and -L must be specified.

Example:

multidec -n4 -l9e-9 -c20e-12 -r5.3 -x5e-12 -k0.7 -otest -L5.4

This utility was written by J.S. Roychowdhury for use with the lossy transmission line model [13].