Is “db” or “dbi” a better measeure of RECEPTION?
When someone talks about dB they really mean to say dBi or dBd, at least when it comes to wifi signals. The term “dB’ just means decibel, but “decibel” is not specific enough to be useful in regards to antenna gain (i.e. the “power” of the antenna). The term “dBi” means “decible isotropic,” and “dBd” means “decible dipolar”. You see, the reception capability of an antenna is actually measured in two different ways. One is to see how strong the reception of an antenna is given another antenna that sends out a signal in all directions. This is known as being measured from an “isotropic” source. Another way to see how strong an antenna is to use an antenna which radiates a singal in mostly one direction (of course, towards the recieving antenna). This second method, called a “dipolar” source is sort of like cheating — an antenna that has its power focused directly at another antenna is 2.1 dB higher on average. I don’t ever recall reading whether wifi antenna power/range claims were base
