Directional Antennas
Solid dish

A solid parabolic dish can allow WLANs to operate over long distances. It has a narrow beamwidth, and depending on the speed and gain of the antenna used, distances of up to 40 km (25 miles) may be possible. It is important to evaluate how well the dish will withstand icy conditions and high winds. Equally important is the sturdiness of the mast and tower the antenna will be mounted on.

The Cisco high gain parabolic dish is designed to be used as a bridge antenna between two networks or for point-to-point communications . It consists of an aluminum parabolic reflector and feed antenna. The antenna features a rugged mount. It also offers 20 degree fine adjustment for both horizontal and vertical planes. The antenna is provided with hardware for mast mounting. The dimensions are shown in Figure . The radiation pattern is shown in Figure .

The 5 GHz 28-dBi dish antenna is a non-diversity parabolic antenna which operates in the UNII-3 band (5725 to 5825 MHz) . The antenna is designed to be mounted outdoors on a mast. The antenna is also designed to be used at either or both sides of a point-to-point installation or the non-root side of a point-to-multipoint installation. The radiation patterns are shown in Figures and . When the antenna is used at both sites, point-to-point line-of-sight (LOS) range can be extended up to 12.9 miles (20.7 kilometers) at 54 Mbps. When the antenna is used at a client site and a 10-dBi sector antenna is used at the hub site, point-to-multipoint LOS range can be extended up to 3.8 miles (6.1 kilometers) at 54 Mbps.


Lab Activity

Lab Exercise: Directional Antennas

In this lab, students will test the range capabilities of the Cisco Aironet AP with a directional antenna configuration.