Provided by: ngspice_23-1_amd64 bug


       ngmultidec - make ngpice sub-circuit for coupled transmission lines


       ngmultidec [ options...  ]


       ngmultidec  writes  an ngspice input file to standard output which describes a sub-circuit
       for coupled lines using uncoupled simple lossy lines.

       Each generated subcircuit models  a  4-conductor  transmission  line  with  the  following
       parameters:  length  l,  line  capacitance  c,  line  resistance  r,  line  conductance g,
       inductive_coeff_of_coupling k, inter-line capacitance cm, length  l.   Derived  parameters
       are:  lm,  ctot.   The  values  of  l, c, the model name, the number of conductors and the
       length of the line must be specified.

       It is important to note that the model is a simplified one - the following assumptions are
       made:  1.  The  self-inductance  l,  the  self-capacitance  ctot (note: not c), the series
       resistance r and the parallel capacitance g are the same for all lines, and 2.  Each  line
       is  coupled only to the two lines adjacent to it, with the same coupling parameters cm and
       lm. The first assumption implies that edge effects have to be neglected.  The  utility  of
       these  assumptions is that they make the sL+R and sC+G matrices symmetric, tridiagonal and
       Toeplitz, with useful consequences (see the paper referenced below).

       It may be noted that a symmetric two-conductor line  is  represented  accurately  by  this

       Standard  C  language  scientific  (exponent)  notation  may  be used for options' numeric


              Set the subcircuit name

              Set the line inductance.

              Set the line capacitance.

              Set the line resistance.

              Set the line conductance.

              Set the value of the inductive coefficient of coupling, whose absolute value k must
              be less than 1.0.

              Set the line-to-line capacitance.

              Set the length of the line.

              Set the number of conductors.

       -u     Write a usage message to standard error.


              ngmultidec -n4 -l9e9 -c20e-12 -r5.3 -x5e12 -k0.7 -otest -L5.4 > test.cir


       Efficient Transient Simulation of Lossy Interconnect,
       J.S. Roychowdhury and D.O. Pederson,
       Proceedings of the Design Automation Conference,
       pp. 740-745.

       ngnutmeg(1), ngproc2mod(1), ngsconvert(1), ngspice(1), nghelp(1).

                                              ngpice                                NGMULTIDEC(1)