If you want to jam a signal the easy way, you need to produce more power than the signal, at the same frequency, at the receiver. If you are both using standard dipole antennas then the power drops off with 1/r^2 and you just need to find the line where the received power from the jammer and transmitter are equal - on one side of that line the signal gets through, on the other it does not.
For example:
Transmitter, 50 kW
Jammer, 100kW, 5km away
On the line joining the two, the Transmitter wins up to 12.07km away ( on the transmitter's side) and 2.07km away ( on the jammer's side) so as you walked that line, you would be able to hear the transmitter for 12km, then you would hit the transmitter, then 2km later the signal would be gone (still 3km from the jammer).
|