Fan-beam antenna

A fan - diagram is called the directional pattern or antenna pattern of a directional antenna or antenna array, if it is in one dimension has a very small opening angle and in the other dimension a large opening angle.

Such a chart is obtained, for example, by

• One is used in a narrower dimension parabolic reflector or just a section of a paraboloid segment,
• A plurality of antennas are arranged in a one-dimensional antenna array.

The greater the extension of the reflector of the antenna array or, the smaller the angle in this dimension.

Applications

Vertical compartments

Vertically aligned (standing ) subjects diagrams of secondary and primary radars used to detect various altitudes in still outstanding horizontal angular resolution can.

Horizontal compartments

Horizontal, " lying " fan charts have, for example, height finder radars. The horizontal angle whose subjects diagrams is a few degrees while the vertical angle is often less than one degree. Also radio stations in VHF, VHF and UHF bands often have a characteristic horizontal compartments to the transmission power bundled towards or slightly radiate below the horizon. In this way, unnecessary radiation into space or towards overreach is causal inversion layers avoided. Antennas of the mobile network also have horizontal compartments diagrams. Both this radio station use to vertical antenna array whose individual elements are driven out of phase if necessary something to spite vertical installation to tilt the fan on a pole a little towards the earth's surface.

• Antenna diagram
• Radar