Help Signal drops when charging?

So, just now, I noticed when charging the phone, it drops nearly all bars. I usually get 5-6 full bars at home. I was just charging the phone and noticed I only had 1. I waved it in the air, and moved around a bit, but still only 1 bar. As soon as I unplugged it, bam, full 6 bars. Plug it back in, bam, 1 bar. Anyone else notice this?

FYI I always charge via usb from my laptop if that makes a difference.