Hi D. Marathe, 

Thanks for the reply. The issue with setting the Global material as air is that the floquet port plane wave will not enter the water as expected due to snells law. For example if I want the water plane wave to arrive at 40 degrees, it will refract from the beginning and appear to enter at 4 or 5 degrees. If I set the global material to water however, the plane wave arrives correctly but then I cant view the far fields assuming an air medium.