Low-cost multi-objective design of compact microwave structures using domain patching

A good compromise between size and electrical performance is an important design consideration for compact microwave structures. Comprehensive information about size/performance trade-offs can be obtained through multi-objective optimization. Due to considerable electromagnetic (EM) cross-couplings in highly compressed layouts, the design process has to be conducted at the level of high-fidelity EM analysis which is computationally prohibitive when using conventional methods (e.g., population-based metaheuristics). Here, we perform multi-objective design of compact structures using a domain patching algorithm. It is a low-cost and deterministic procedure for constructing the path connecting the extreme Pareto-optimal designs (obtained through auxiliary single-objective optimization runs), executed at the level of coarse-discretization EM simulations. The final representation of the Pareto front is then generated from response correction techniques. Our approach is illustrated through a compact impedance matching transformer.