For those of use who need some things said in simple words before we start doing the difficult math..
It would be great if someone familiar with them could provide a succinct qualitative description of what is a Floquet Port, a Floquet Mode, and what would motivate trying to apply them.
______________
Where we have been so far..
Google "Floquet" and you discover it is "a branch of ordinary differential equation theory"
https://en.wikipedia.org/wiki/Floquet_theory
OK, such equations are encountered in wave theory..
More searching, and we discover there are expressions for "Simple Plane Wave (Fundamental Floquet Mode" - So there are "Floquet modes" presumably special compared to ordinary "modes"
Still not clear about Floquet Modes, we see there are also "Higher Order Floquet Modes" with complex exponential expressions. I kind of expected that.
We find "Floquet Ports" - as opposed to "modes, as a tool available in some simulators. Not sure now..
_____________
PS Edit:
After more searching, I find they are often associated with simulating a cell that would be part of a larger array, to break up a huge and possibly un-viable calculation. Also, they seem to involve plane wave excitations of a specially useful solveable kind. Hmm.. I still don't understand them..