I was just reading about non-lethal microwave weapons -- apparently they are aiming to put them on planes. The thought struck me, what kind of armour would be effective against this sort of weapon? I assume a Faraday type cage might work. But would this give off sparks in the same way sticking a metal container in a microwave would do? A real light show on the battlefield. And how portable would this armour be?

This is not for a story. I am just curious and I assume, since the article I read mentioned that the weapons were being used at the lowest possible setting, that a lethal version is pretty much inevitable.

Thanks in advance for satisfying my curiosity.