Multiconductor Transmission Line Analysis

The program CONMTL includes a method of moments (MoM) technique. After the numerical computation of the equivalent surface charge distribution, which is the solution of a system of linear equations, the per-unit-length parameters are determined. This data is the basis for a subsequent evaluation of the transmission line Y matrix.


  • Per-unit-length parameter matrices [C’], [L’] for a large variety of cross sections including substrate or dielectric coating
  • S-parameter matrices for usage in external network solvers (Touchstone format)
  • Selected S-parameters as a function of frequency
  • E field distribution in the transmission line cross section

In HDF5 format the Y matrix of the transmission line can be loaded into the network solver CONCIRC where the corresponding conductors can by terminated by lumped loads for example.

The graphing utility „Gnuplot“ is used for displaying S-parameters as a function of frequencyy and needs to be installed additionally. Gnuplot is not part of CONMTL.

It is recommended to download the following version of gnuplot: p528-win64-mingw.exe 

Attention: Gnuplot version 541 level 1 does not run  with CONMTL (7.01.21)

  • Download: The download link will be sent by e-mail after submitting the contact form.
  • Installation: PDF
  • CONMTL manual: PDF
  • ChangeLog (March 2020): PDF
Picture of CONMTL GUI

Graphical user interface (Source: TET, TUHH)

Picture of CONMTL GUI

Graphical user interface (Source: TET, TUHH)

CONMTL is combined work according to the LGPLv3 conditions.

  • Qt source code download
  • Instruction for relinking to a modified version of Qt PDF

(Source Wikipedia)

CONMTL uses the HDF5 format for storing data.