Simultaneous perturbations gradient approximation for optimization of planar structures

An approach is proposed to reduce the number of required computations for gradient approximation. Due to the time consuming nature of electromagnetic numerical analysis, reducing the number of required simulations in the optimization process has a significant effect on the design lead time. To this end, simultaneous perturbations are used instead of the classical finite difference approximation. Under reasonably general conditions it could be shown that only two cost function computations will provide an accurate gradient approximation which is a drastic improvement compared to 2N calculation.