I saw a demonstration of an RF detector being brought close to a mobile phone. As the detector was moved away, the number on it dropped to zero. How can that be? Shouldn’t there be some RF signal from the phone all the way to the cell tower, so that the phone can communicate with the tower?

Question

I saw a demonstration of an RF detector being brought close to a mobile phone. As the detector was moved away, the number on it dropped to zero. How can that be? Shouldn’t there be some RF signal from the phone all the way to the cell tower, so that the phone can communicate with the tower?

In: Technology

Answer 1

Electronics technician here. The receiver in the handheld detector is not sensitive enough. Also, the general principles of the dissipation of energy through space is best understood by reading about “The Inverse Square Law”. It says that signal gets weaker the further you are away. In actual fact the signal continues to infinity, in an ever weakening wave.