Sure, foil will dissipate the energy as induction current generated heating. How much of that can a Reynolds Wrap covered rioter stand? The original unit was about 2MW with a range of about 600 meters.
NOAA built a smaller W-band unit for measuring hurricane generated sea spray from a low flight level hunter aircraft. Appears about the right scale for a home brew unit. Delivers about 1700 watt output from a tube final stage.
Here is a starting point:
https://psl.noaa.gov/spotlight/2013/pdf/spotlight-wBand-P3.pdf
“How much of that can a Reynolds Wrap covered rioter stand? The original unit was about 2MW with a range of about 600 meters.”
Maybe, but that energy isn’t focused on a single person, it’s being broadcast as a wave and so the actual current that could be induced around someone say, 50 meters away, would be much less, probably not anything actually harmful if I had to venture a guess.