Aerial-Only EMP Bombs?

Are there such things as EMP bombs, that if detonated way up, tens of thousands of feet in the air, that it would take down airliners and UAVs, but to also be so high up, that it wouldn't affect any on-ground power grids, or cars, etc.? I'm writing a story where one is mounted in a warhead-like tip on a missile, and at about 80,000 feet, it goes off with a fixed radius from 80,000 to 10,000. I was wondering if there are any real-life equivalents. Not the missile itself, but something that if a terrorist took it on a plane, that when it went off, this EMP wouldn't affect anything on the ground. Any suggestions?