Electromagnetic waveguide port boundary condition

Hello all.
As a followup to the work presented at FEniCS 2026, I have finished the first version of a somewhat detailed description of the waveguide boundary condition implementation using DolfinX 0.9. It can be found here.. The code I used to verify the method is on Github.

What I would like to do is improve the waveguide mode generation procedure. In the present verification of the method, I used analytic functions that describe the electromagnetic mode profiles, since the empty waveguide example is a very simple structure. To handle more complicated waveguide structures (like multiple microstrip or coplanar waveguides), I need to numerically generate the port waveguide modes using a 2D EM solver. I need to generate 2D submeshes over the waveguide ports in the 3D structure where I solve for waveguide modes.

As I see it, I need to:

  • Install newer version of DolfinX (11 as suggested at FEniCS 2026 meeting)
  • Learn to generate submeshes over 2D port surfaces
  • Solve for propagating modes in ports
  • Apply port BCs to 3D model using modes generated by 2D model on submeshes
  • Solve full 3D model

First things first - a question: Is there a Spack installation for version 11 of DolfinX? (Spack is my preferred installation method.)