(1) Target location in azimuth and elevation is given by the physical
position of the antenna.
(2) Radar antennas must be highly directional so that they can give
accurate angular information.
(3) A radar antenna consists of a reflector and a feed.
(4) RF energy is fed to the reflector by means of a dipole, horn, or
resonant cavity.
(5) The shape of the reflector depends upon the function of the
radar.
(6) A parabolic or dish antenna, used with tracking radars, focuses
the RF energy into a narrow cone-shaped beam.
(7) Parabolic cylinders and orange peel antennas are used with search
and height-finding radars.
(8) An orange peel antenna used for search has a radiation pattern
that is narrow in azimuth and broad in elevation.
(9) An orange peel antenna used for height-finding has a radiation
pattern that is narrow in elevation and broad in azimuth.
(10) A metallic lens is used with search and tracking radars.
34. Reflector feed systems.
a. Conventional front feeds. In a front feed system, the transmission
line (rigid coaxial line or waveguide) is led around the edge of the antenna
to the front, where it is terminated by a radiating device as shown in
Figure 155.
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