Comparison of different optimization strategies in the design of electromagnetic devices

Both higher-order deterministic optimization methods (steepest-descent, conjugate gradient, quasi-Newton) and zeroth-order stochastic optimization methods (( mu + lambda )-evolution strategy) have been tested for designing electromagnetic devices. The underlying field analyses have involved the finite element method in 2-D and 3-D, both linear and nonlinear. Numerical experiments indicate some preference for the ( mu + lambda )-evolution strategy not only because of its robustness and generality, but also its speed of convergence.