Nice idea but clearly an amateur.
Trying to use jamming = absence of signal to set off a bomb requires knowing exactly how and when jamming is turned on. If the goal is protection of a crowd, the jamming likely starts immediately - before the crowd gathers - so an absence of signal trigger would just kill the person's placing the bomb (or flipping the activation switch).
Then there's the little problem of testing. How do you test the absence of a signal is working correctly? What if you just connected the wiring wrong? Or you go through a blind spot/tunnel/elevator?
Read up on positive/negative action triggers.
Biting the hand that feeds IT
