Dual-Layer Reflectarray

Hey Friend's

I am trying to simulate a dual layer reflectarray with substrate thickness of 0.5mm each.
The combined loss of the structure is around 10dB, if i remove the patch from bottom substrate the loss still remains 10dB.
I want to ask that if the loss in both cases is same then how can i say that i designed a reflectarray using dual layer configuration as
the performance is same in presence or absence bottom patch?

Anyone who tried or ever worked on dual-layer structures can provide suggestions.