In the paper they were measuring signal gain between two antennas, and as such the 6dBm gain appears to be the effect of collating more of the beam spread into the receiver (as one would expect of a lens). Given my schedule I don't think I'll have enough time to print one by November but it would make for some excellent discussion! Reading the permittivity paper that was linked here was also quite good and I'm wondering if something could be integrated into openEMS which would tie the two together.

I'm also tickled by the idea of a 'Newtonian' RF telescope using two lenses.