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atlc

Computes impedance of a transmission line of any cross-section, from a picture of it

What it does

You draw the cross-section of a transmission line as a bitmap -- conductors in one colour, each dielectric in another -- and it solves the field numerically to give characteristic impedance, capacitance, inductance, velocity factor and loss. Coax, twin-lead, stripline, or a shape no formula covers: it does not care, because it is not using a formula.

Why you would want it

Every closed-form impedance equation assumes a geometry. The moment you build something the textbook does not have -- a coax with an off-centre conductor, a balun wound on an odd former, an air-spaced line with supports, a stripline on a board with two dielectrics -- the equations stop applying and this is the tool that still answers. It is also how you check a homemade line before trusting it with power.

Before it will work

A bitmap of the cross-section, drawn to a colour convention the manual specifies, and the patience to make the pixel scale right -- resolution is accuracy here.

How it installs

  • apt: atlc

Known problems

It is command-line only with no bundled drawing tool, so producing the input is most of the work and the colour convention is easy to get wrong; a mistake there yields a confident number for a structure you did not intend. Convergence is slower the finer the mesh, and a high-resolution bitmap can take a long time. AHRL installs it from apt with no menu entry for the same reason: it is a tool for someone who already knows they need it.

Keeping it current

  • probe: apt policy
  • strategy: apt_upgrade

Where to get help with the software itself

Debian's package declares no upstream Homepage and the original site is not cited by it, so the package tracker is the honest pointer rather than an invented one. The manual pages shipped with the package are the real documentation.

Source: catalog/packages/atlc.yaml