Optimisation of contoured beams for satellite antennas

One of the basic problems of realising an optimum contoured beam, together with sidelobe suppression, is the determination of the excitation coefficients for the individual horns of a reflector and horn-array geometry. The Fletcher-Powell and the Minimax methods of optimising an arbitrary coverage with sidelobe suppression have been studied. The paper presents the formulations applicable to the Fletcher-Powell and the Minimax methods. The Brasilsat antenna is used as the test case. Results obtained using the two methods, and also by manual optimisation, are presented and compared.