I finally got this tonight after getting 13 kills with C4/Claymore/AT Mine. I did it on Karkand by using C4 all the time. I basically ran towards an enemy, tossed C4 at his feet and then blew both of us up. I ended up with 2 points in the round (wow!) but I did get the badge!
I also got the Basic Aviator badge by spending 10 minutes in an airplane and realizing just how bad I am at trying to bomb things.Battlefield 2