Directional Antennas are generally used for systems that require narrow beam-width and highly directed energy. These narrow beam antennas can provide a large amount of energy over a small coverage area.
When used for point-to-point communications systems (such as satellite links), these very-directive antennas will greatly reduce power requirements. In EW applications, highly directive antennas increase the field strength at the target at a fraction of the cost of higher output amplifiers. The most effective results are obtained when combined with higher power amplifiers.