Learning Forum

[Sylvie]

I am trying to design a Circularly Polarization sensitive metasurface absorber. I want to know , how to Get the Refelctance (or S parameters) when I try to illuminate a metasurface unit cell with a Circularly Polarized wave. The Circularly Polarized wave is being incident on the unit cell through floquet port having two modes, 90degree out of phase from each other. I have only one port here as the side other than the side being illuminated is having a perfect conductor. I am able to plot the S(FloquetPort1:1,FloquetPort1:1) ; S(FloquetPort1:2,FloquetPort1:2); ActiveS(FloquetPort1:1) and ActiveS(FloquetPort1:2) plots. Now, I am unable to get the Reflectance of Circularly Polarized wave ,as addition of the Active S-Parameters gives me same result for both handedness of the incident CP wave. In a latter stage, I also want to develop the unit cell absorption.nnAny help would be appreciated.Arrayn

[Praneeth]

nThanks for reaching us and we appreciate your patience.nCan you confirm that you are looking for extracting the S parameters of the combined excitation (Circular polarized wave) with the available modes in the Floquet port or you are not getting different results for different handedness of the circular polarized wave?nAll the very best.nBest Regards,n

[Sylvie]

Thank you for your reply.nYes, I am looking forward to extract the S parameters of the combined excitation (Circular polarized wave) with the available modes in the Floquet port. nI am able to see differences in ActiveS Parameters when the handedness of the circularly polarized wave is changed, as my unit cell is asymmetric. My structure is supposed to absorb a particular handedness (say Left Handed Circular polarized) of CIrcularly Polarized incident wave, and reflect the waves which are of orthogonal polarization (here, Right Handed Circularly polarized). nLooking forward for a solution.n

[vamshikollipara]

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[rtk]

,nYou can try giving the geometry with the metamaterial characteristics. This can be done by editing its material properties.nAfter that for excitation, give the configuration of Circular Polarization. That means in edit sources, provide mag 1 at 0 degrees and 1 at 90 degrees. This should give you an appropriate S-parameter extraction.nHope this addresses your concern.nnRegards,n

[Sylvie]

Thank You Arrayfor you reply.nYou are right. But after giving the configuration you mentioned, I get two parameters as ActiveS(FloquetPort1:1) and ActiveS(FloquetPort1:2) as two separate plottable parameters. I have only 1 port on my structure. nCould you please tell mw, how do I extract S11 (i.e, Reflection coefficient) for Circularly Polarized wave from the ActiveS parameters, where my excitation contains two modes(one with mag 1 and phase 0deg; and another with mag 1 and phase 90deg)? nPlease let me know if you need further clarification.n