Generally you see a row of vertical up slightly downward sloping plate-like objects on the roof, is the antenna. If you are in a place where houses are scarce, you will be specially built to hang the base station with a communication tower, at the top of the tower, there is a circle of rectangular plate-shaped things in the gleam, is the antenna.

In addition, it senses and receives weak signals from cell phones and collects these signals and sends them to the RF unit to extract information from them.

Typically, a base station contains three antennas, each transmitting signals in a 120-degree direction around the perimeter, which together provide seamless 360-degree coverage.

If we look closely at the bottom of the antenna, we will find that there is a strand of thin black wires extending downward, these cables are the feeder lines, which are used to connect the RF unit and propagate electromagnetic waves to the antenna, and together with the antenna they form the antenna feeder system.