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
.