In this Thesis, an antenna with a cosecant squared pattern to work as a radiating vertical array of SSR antennas is designed. A simple microstrip structure is adopted to design as the feed network and 11 elements of half-wave dipoles. In order to achieve desired pattern, amplitude and phase of elements are obtained using a synthesis pattern method. Some Special Wilkinson power dividers are used to prepare desired power amplitudes to feed the elements. The designed antenna has nearly 10 dB gain and its main beam in the elevation plane is 9 degrees above the ground. Its -10 dB Beam width in elevation pattern is 50 deg. The return loss in central frequency is 22 dB. RT Duroid 5880 ( ? r =2.2 and tan ? =0.0009) with thickness of 31 mil is used as the substrate. Keywords: Cosecant Squared Pattern, Secondary Surveillance Radar (SSR), Printed Half-Wave Dipole, Fourier, Chebyshev and Taylor Distribution.
