The shaped cosecant squared pattern is one of the usual patterns that are used in the searchantenna andsurveillance radar systems and has impressive effect in these type of radar systems.One of the important characteristics of this pattern is the constant received power from the target that is flying atconstant height from the earth (with the assumption that the target Radar Cross Section (RCS) is constant).Another one is satisfyingcoverageof vertical detection that cause have no target missing in radar systems.Different ways are suggested to generate this pattern. Among these usual ways, forming the surface of the reflector or using the stacked beams method for reflector antenna feed; can be referred.In stacked beams, each of these feeds produce special beam.After that with using the microwave circuit named matrix, these beams are combined with different weights and construct the desired radiation pattern.In this thesis, as the building of the shaped reflector or matrix cause many problems and complicated snags;alternative ways are studied. It means that without any reflector shaping and feed changing,the desired pattern will be constructed. So in the beginning,the two usual ways are studied and the reflector formation way is analyzed exactly.Also this way is numerically simulated with FEKO software and the important parameters in designing are extracted. With the help of extracted outcome the idea of using antenna feed with appropriate lens in front as the parabolic reflector antenna feed; issuggested and analyzed.But for the reason of impractical construction, this idea is not useful and have to beoverruled.In continuance using the two horn antennas for the feed is studied and simulated and at the end of the thesis;linear dipole array antenna is suggested as the parabolic reflector feed. Also by using the genetic algorithm,the appropriate phase and amplitude of all elements are extracted.Therefore this antenna array is implementedby using a pair line structure in traveling wave state which feeds by couplers.In this thesis, all the reflectors and their feeds; are designed to reach the bandwidth of 100 MHz and gain of 33 dB with the average power of 10KWatts at the center frequency of 1.3GHz. Keywords: Shapedreflectorantenna,Parabolic reflector, Radiationpattern, Cosecant-square