Hi all,
I recently faced a very strange problem after a long time of using periodic ports. I would really appreciate if someone can help me.
I am simulating a metsurface. As usual, I defined two ports (1 on, 1 off) and looked into the S parameters. However when I compared the S parameter results with the field distribution they don't match at all! For example, in a wavelength range whrere S11 is around 1, the field distribution shows the main part of the field transmitted.
This time I replaced port 2 with a PML boundary condition and get a completely different S11. The new S11 also matches well with what I expected.
Now I wonder what is my mistake here.** Specifically**, my question is about the position of the periodic ports (how far they should be from the scatterer) and the Mode phase (I had usually set it to 0 and got good results, how exactly I should define it now?).
Thank you very much.