Whats the difference between 0db (unity), 3db, 6db gain?
0-dBd gain mobile antenna radiates more energy higher in the vertical plane to reach radio communication sites that are located in higher places. Therefore they are more useful in mountainous and metropolitan areas with tall buildings. A 3-dBd gain antenna is the compromise in suburban and general settings. A 5-dBd gain mobile antenna radiates more energy toward the horizon compared to the 0 and 3 dBd mobile antennas to reach radio communication sites that are further apart and less obstructed. Therefore they are best used in deserts, plains, flatlands, and open farm areas.
