The amount of wizardry required to make this work would put every teacher at Hogwarts to shame.<p>The frontend looks like something completely alien. I am pretty sure the amount of metal is to get rid of complicating effects of having PCB anywhere near the sign and to be able to machine it so that signal paths are matched to something like micrometers. I sort of understand principles, but same way as understanding principles of electromagnetic wave reflection and propagation tells you nothing about how to make invisible planes.<p>I wonder if the frontend is result of finding solutions to equations, meticulous computer modeling or just humongous number of experiments (sort of like aerodynamic tunnel work).