Good question

Good question

CST has a component library that gives lots of examples. One of them is a slow-wave component based on the eigenmode solver. HFSS also has a tutorial (HFSS Left-Handed_Metamaterials_for_Microwave_Engineering). Another intuitional way is to model a unit cell with wave/discrete ports, or more accurately, model ten or more cells with actual feeds (10.1109/MAP.2020.3003210 ).

Actually, focusing on plane waves is not the problem. It also calculates the equivalent surface impedance tensor and then derives the propagation characteristics of guided waves. Papers on left-handed TL, leaky-wave antennas, and metasurface/ holographic antennas could be helpful.

10.1103/PhysRevE.70.016608; 10.1103/PhysRevE.71.046610; 10.1103/PhysRevE.71.036617; 10.1109/TAP.2016.2562662; 10.1109/TAP.2010.2055812

Hello,

For such cases, use either magnetic/electric boundaries or unit-cell boundary condition. For magnetic/electric boundaries, it is need to be define wave-guide ports but for unit-cell boundary condition, there's no need to define port. It automatically defines two ports. Go for: 1) choose your desired direction based on the application. As, for FSS structures, the incident direction is Normal to the surface. 2) Open boundaries are not suitable for analyzing metamaterial cells as it tends to ignore the edge diffraction when dealing with these periodic structures. we use open boundaries only for finite structures. Magnetic/electric boundary conditions come from the fact that to create a plane wave (TE or TM mode) using wave-guide port which is not useful for producing planewaves. As a result, use of this configuration to create your desired TE/TM wave toward the cell.

File are attached.

Thanks,