Numerical Electromagnics Code (NEM)

nec2.org

28 points·hyperific··9 comments

What’s the latest on open/free solvers to replace HFSS/CST?

Best one I know of as a direct replacement is AWS PALACE: https://awslabs.github.io/palace/stable/

Of course, you have to interact with the solver through JSON files and provide your own initial mesh. They recently added adaptive refinement but I don't know how well it works. Given what Ansys charges for an HFSS seat though can't complain!

Wow, is there a Kicad script for generating input for this tool based on a pcb layout? That would be awesome!

Relatedly, is there a good open replacement for ADS/Microwave Office? I've seen QUCS/QUCS studio but don't know if there's others out there? Last I looked, the more general SPICE solvers don't support S-param blocks and transmission lines, which are pretty critical.

Depends what you're doing and how maths-y you are since you need to tell it the equations you want to solve, but FEniCs is a very good general purpose FEM code, and you can couple it to Bempp for BEM stuff.

OpenEMS has a lot of mindshare in that area. Not sure how effective it is at replacing proprietary packages like HFSS, though.

Does HFSS visualize the field in real-time or a user needs to set the geometry/parameters then precalculate the field and only then be able to explore the visualization?

Say, if I wanted to see immediate effects of changing an incidence angle, could I just "scroll" the incidence parameter?

HFSS does a typical FEM matrix solve then displays the results. It is often used for very complex or large problems, so as far as I know it isn’t set up for instant display of results. That would be a neat feature for small problems.

*NEC

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