Directional Antennas
Yaqi

A Yagi antenna, shown in Figure , is a high-gain directional antenna. The Yagi is constructed of at least three elements, which are metal bars that supplement the wave energy transmitted. In a Yagi antenna, there is at least one driven element, one reflector element, and usually one or more director elements. The Yagi antenna is also known as a linear end-fire antenna or a Yagi-Uda array. The dimensions are shown in Figure .

Yagi antennas are directional and designed for long distance communication. The radiation patterns are shown in Figures through . A Yagi is usually smaller, lighter, and cheaper than a dish antenna. A Yagi is great for outdoor applications and some indoor applications. The Cisco Yagi provides 13.5 dBi of gain and features a range of up to 10 km (6.5 miles) at 2 Mbps, and 3.2 km (2 miles) at 11 Mbps. Most Yagi antennas are mounted with U-bolts, to a sturdy mast.

The elements can be seen in the bare Yagi in Figure . The element parts are labeled in Figure .