What is this dBi Gain thing I keep seeing on antenna specs?
How much an antenna amplifies or concentrates the signal. Basically it’s how much more “powerful” the antenna is over an imaginary dipole antenna. I say imaginary because nobody makes one, but it would be an antenna that spreads the signal in every possible direction, in the shape of a sphere. Such an antenna would have zero Gain. So for example, a 24dBi gain parabolic grid is a very focused antenna, it narrows the signal into a fine beam of coverage in one direction. It doesn’t use or provide any more power than a dipole, it just focuses all that signal into one spot, so it goes farther. A good analogy would be that of the light bulb in a torch. Unscrew the cap and lens so you just have a bare bulb, and your immediate area will be quite bright, but it doesn’t go very far. This would be akin to a 1 or 2dBi antenna. Now put the cap back on and the parabolic dish will focus the light into a tiny little spot, and shine it down a hallway. Your immediate area isn’t very bright, except for t
