How do you create burst's of EMP's to disrupt signals?

Answer 1

The nuclear bomb method works, but has lots of undesirable side effects, and violates all sorts of treaties. EMP bombs involve creating a powerful magnetic field in a coil, and rapidly collapsing it with an explosive charge. More modest weapons, such as might be used to disable a vehicle at close range use rapid switching or capacitive discharge to produce enough of a pulse to damage nearby electronics.

Answer 2

The most commonly known involves a nuclear or thermonuclear blast. Other technologies are being considered.