Learning Forum

[Oliver Csernyava]

Hi All!

I'd like to ask about a confusion of mine regarding periodic structures in HFSS.

I'd like to model a linearly periodic sphere structure (infinite periodicity) with an oblique incident Plane-wave.

As far as I understand, I need the 'Coupled' boundary condition (Primary, Secondary) for the faces of the periodic dimension. Otherwise, I can use PML on the remaining faces. Then the excitation can be a Plane-wave set for the specific incidence.

The parameter that is not clear is the 'Scanning angle' or, as I understand, the phase difference between the two Coupled boundary surfaces. I would understand this Scanning angle as a virtual incident Plane wave from that direction, helping to imagine the phase compensation on the boundaries. However, assuming this theoretical model for the Scanning angle, I don't get the correct results for the solution.

I would like to ask if the described way to model an infinite periodic structure, with an oblique incident plane wave is correct, or if there is another way. Also, what is the meaning and significance of the Scan angle property of the Coupled boundary condition?

Thank you for all the comments in advance!