Fan-beam antenna
Encyclopedia
A fan-beam antenna is a directional antenna
Directional antenna
A directional antenna or beam antenna is an antenna which radiates greater power in one or more directions allowing for increased performance on transmit and receive and reduced interference from unwanted sources....

 producing a main beam having a narrow beamwidth
Beamwidth
In telecommunication, the term beamwidth has the following meanings:1. In the radio regime, of an antenna pattern, the angle between the half-power points of the main lobe, when referenced to the peak effective radiated power of the main lobe....

 in one dimension and a wider beamwidth in the other dimension. This pattern will be achieved by a truncated paraboloid
Paraboloid
In mathematics, a paraboloid is a quadric surface of special kind. There are two kinds of paraboloids: elliptic and hyperbolic. The elliptic paraboloid is shaped like an oval cup and can have a maximum or minimum point....

 reflector or a circular paraboloid reflector. Since the reflector is narrow in the vertical plane and wide in the horizontal, it produces a beam that is wide in the vertical plane and narrow in the horizontal. (The larger the antenna dimension, the narrower the beam.)




Figures: A truncated paraboloid reflector and its antenna pattern (a: lateral view, b: frontal view)

Fan beam antennas are used in radar sets. Those in height finder
Height finder
A height finder is a ground based aircraft altitude measuring device.Early height finder implementations were optical devices and later migrated to radar devices. Devices combining both optics and radar were deployed by the U.S...

s have the beam oriented horizontally.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK