Design and optimization of 3D multilayer balun architectures using the design of experiments technique

The design of experiments approach has been combined with full wave EM simulations for studying the feasibility of the optimization of a multilayer balun. It was found that it was not possible to obtain satisfactory amplitude and phase balances for the entire frequency band, but the optimization can be performed if less stringent requirements are imposed on the imbalances. The amount of required simulations was a small fraction (more than an order of magnitude) with respect to any other optimization approaches.