Synthesis of cosecant squared pattern in linear antenna arrays using differential evolution

In this paper, a cosecant squared shaped beam pattern is synthesized from a uniformly spaced but nonuniformly excited linear antenna array where the uniform spacing of the array elements is considered as half of the desired signal wavelength. The shaped beam pattern is synthesized for the angular beam width of 320 by reducing the side lobe level (SLL) to -20.06 dB and almost without any ripple in the shaped region. To get the desired pattern, excitation coefficients and the static phase shift of the array elements are taken as the optimizing parameters and the differential evolution (DE) algorithm is used as the optimizing algorithm. It is further observed that the desired array pattern is remained unaltered for a band of frequency on either side of the operating frequency.