Full-wave Coupling Matrix Description in Microwave Filters via Reduced-Basis Approximations in Electromagnetics

Current computational resources are leading electromagnetic computer aided design towards brute-force approaches, where global optimization techniques are taken into account and reduced knowledge of the actual electromagnetic behavior is considered. Within this strategy, the design development time increases dramatically. In this work, on the contrary, we focus on obtaining an accurate and reliable physical-based description of the Electromagnetics we are dealing with in order to carry out a fast and accurate design. Appropriate Finite Element solution to timeharmonic Maxwell's equations in the frequency band of interest is involved and a reliable reduced-order model is obtained. Then, the electromagnetic behavior in the microwave device is rearranged and described in terms of circuit theory, giving rise to the coupling matrix representation in the actual coupling topology of the original Maxwell problem. The ingredients of this methodology are: 1) the use of field solutions at given frequencies as basis functions to reduce the original Maxwell problem, 2) adaptively choosing the field solution frequency samples and 3) change of basis in the reducedorder model in order to get the full-wave coupling matrix description in microwave circuits.