Directional Antennas
Introduction

Directional antennas come in many different styles and shapes. This type of antenna does not offer any added power to the signal, and instead simply redirects the energy it received from the transmitter. By redirecting this energy, it has the effect of providing more energy in one direction, and less energy in all other directions . As the gain of a directional antenna increases, the angle of radiation usually decreases, providing a greater coverage distance, but with a reduced coverage angle. Directional antennas include Yagis, patch antennas, and parabolic dishes. Parabolic dishes have a very narrow RF energy path and the installer must be accurate in aiming these at each other.

The Cisco directional antennas are shown in Figure .