A yagi antenna sends and receives in only one direction, so it's the more powerful of the two. An omni antenna sends and receives in all directions at once, but is weaker than a yagi antenna.
All antennas used in cell phone booster systems are capable of both receiving and transmitting cellular signal simultaneously. There are two main types of outside antennas: yagi and omni. We're going to cover both in this article.
The outdoor yagi directional antenna, usually distinguished by its triangular shape, focuses as much energy as possible to receive and transmit in a single direction. The yagi antenna can receive two to three times the amount of signal compared to the omni antenna. For weak signal environments, a Yagi antenna is the best choice to maximize the amount of indoor coverage area you receive and sometimes it is the only option for extremely weak outdoor signal.
Yagi antennas are typically mounted to a vertical pole on the roof of the building where you're installing the signal booster solution and then aimed in the direction of the cell towers for the carrier you're looking to boost.
An omni-directional (omni) antenna will receive signal from all directions, so it is preferable for environments with adequate rooftop signal for all major carriers if you want to boost multiple carriers inside, or for situations where the outside signal may be reflecting off of obstacles, like mountainous or urban terrain.
Omni antennas can be mounted directly to the edge of a building with the included L bracket, or they can be mounted on a vertical pole to provide additional elevation and clear potential obstacles. No aiming is required for an omni antenna.