. The Bell System technical journal . cular direction. This speci-fication must of course be consistent with all the factors that determine gain,including the reduction due to the required vertical spread of the pattern. Cosecant Antennas based on the Paraboloid It is evident that the standard paraboloidal antennas so far discussed willnot produce cosecant patterns. These patterns being unsymmetrical willresult only if the wave front phase and amplitude are especially controlled. 272 BELL SYSTEM TECHNICAL JOURNAL On the other hand, because paraboloidal antennas are simple and commonit is
. The Bell System technical journal . cular direction. This speci-fication must of course be consistent with all the factors that determine gain,including the reduction due to the required vertical spread of the pattern. Cosecant Antennas based on the Paraboloid It is evident that the standard paraboloidal antennas so far discussed willnot produce cosecant patterns. These patterns being unsymmetrical willresult only if the wave front phase and amplitude are especially controlled. 272 BELL SYSTEM TECHNICAL JOURNAL On the other hand, because paraboloidal antennas are simple and commonit is natural that many cosecant designs should be based on them. Thesedesigns can be classified into two grouj)s, those in which the reflector ismodified and those in which the feed is modified. Some early cosecant antennas were made by introducing discontinuitiesin paraboloidal reflectors as illustrated in Fig. i3. These controlled theradiation more or less as desired over the desired cosecant pattern but pro- NORMALPARABOLOID /SURFACE /. PARABOLOIDSURFACE
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