a) Design a 21-element broadside array with a spacing d = lambda/2. The required array factor pattern should closely approximate the sectoral pattern given by SF = {1 50 degree lessthanorequalto theta lessthanorequalto 130 degree 0 elsewhere Determine the excitation coefficients using the Fourier method and compare the resulting pattern with the desired pattern (plot of the normalized patterns) b) Calculate the progressive phase shift of excitation to scan the main beam to the direction 60 degree. c) Use the results from part (a) and part (b) to plot the resulting radiation pattern in dB