recntly there was a patent for a gas filled half-reflective balloon to be used as a low weight dish for radars on blimps.
combine this technology with an EMP bomb situated at the focus. you then have a high power microwave beam thats focused.
it would work like a car headlamp. only a target it was aimed at would be fried.
for aiming technlogy simply have a small radar at the focus,
or some sort of optical seeker on the front of the charge.
be a nice way to do an incoming missile over, and seeing as the balloon is inflatable you could pack a few of em in a missile.
possibly they could be deployed from a high altitude aircraft.
what do you think?