Introduction to directional antenna

A directional antenna is used to receive signals from a specific direction source or to transmit signals in a specific direction. The directivity of an antenna is determined by the energy input into the main direction of the antenna. In theory, minus the interconnection and antenna losses, the absolute directional antenna can send all the signal energy in a single straight line.

The directional antenna, in the horizontal pattern, appears as a certain Angle range of radiation, that is, it has direction. As with omnidirectional antennas, the smaller the lobe width, the greater the gain. The directional antenna is generally used in the communication system where the communication distance is long, the coverage area is small, the target density is large, and the frequency utilization is high.

Flat and patch antennas are also directional antennas and are commonly used in cellular, wireless and backhaul applications due to their thin shape and high directivity.