You should. The technical requirements for what you propose are far more difficult to overcome than you might think. The terrorist that does not think of these things is likely to find himself in the middle of a premature detonation of his own device, thereby not hitting his intended target.

Some of these things involve transporting an unstable liquid, EMI interference between the initiator and the transmitter, transmission harmonics, metal shielding the transmitter, etc. Building bombs is an extremely dangerous job, get it wrong only once and chances are you will not survive the error. Many would-be terrorists have found this out.

This does not make accomplishing the job impossible, just quite a bit more complicated than you seem to understand.