[@Cleverbird] That's actually why I specified 'directed EMP'. A faraday cage definitely increases resistance to the standard EMP that's usually caused as a side effect of explosions and other radiation spikes. A directed EMP is more like aiming an insanely high powered microwave directly at a target. Naturally, just as preventative measures are created so are more effective weapons. You make something immune to a modern EMP? The modern EMP evolves to surpass that immunity (and vice versa). We're also talking alien tech...of aliens that have been invading for ~6000 years and gathering information on human technology. Unfortunately humans haven't gotten much intel on [i]them[/i] as the only units the aliens seem to send are simple cannon fodder with basic energy weapons. 

I was mostly just concerned on where that armor plate was going to fit...since it would've been up to your suit's knees in thickness. 400mm is much more understandable. Thanks for your consideration.