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In this paper, a technique for rapid re-design of compact microwave couplers with respect to operating frequency is discussed. Our methodology involves an inverse surrogate model setup using several reference designs optimized (at the level of equivalent circuit representation of the coupler) for a set of operating frequencies within a range of interest. The surrogate establishes the relationship...
In the paper, the problem of fast multi-objective optimization of compact impedance matching transformers is addressed by utilizing a novel Pareto ranking bisection algorithm. It approximates the Pareto front by dividing line segments connecting the designs found in the previous iterations, and refining the obtained candidate solutions by means of poll-type search involving Pareto ranking. The final...
Fast multi-objective design optimization of compact microstrip impedance transformers is discussed. Our approach exploits approximation models constructed using sampled coarse-mesh EM simulation data in a partitioned design space and response correction techniques for design refinement. Demonstration example of a 50-to-130 ohm wideband transformer is provided.
A rapid statistical analysis and yield estimation of compact microwave couplers involving multiple performance parameters has been presented. The analysis is realized using a fast surrogate model representing appropriate characteristic points of the coupler response. Because of less nonlinear dependence of the characteristic points on the structure geometry (compared to the original response, i.e...
A technique for rapid EM-driven design optimization of compact microwave couplers is presented. Our approach exploits response features and adjoint sensitivities and allows for low-cost design closure both in terms of performance enhancement and structure miniaturization. It is demonstrated using a compact rat-race coupler working at 1 GHz and compared to adjoint-based gradient optimization.
Geometry scaling of compact microwave structures is a challenging problem because of complex relationships between the physical dimensions and electrical characteristics, mostly caused by considerable cross-couplings in densely arranged layouts. Here, a procedure for expedited dimension scaling of compact microwave couplers with respect to two independent criteria has been presented. Our approach...
Fast and accurate replacement models (surrogates) are indispensable in the design of microwave and antenna structures. Conventional data-driven modeling of antennas is usually prohibitively expensive in terms of data acquisition due to highly nonlinear responses of typical responses (e.g., reflection coefficient versus frequency). In this paper, a technique for reduced-cost modeling is proposed. The...
A framework for low-cost EM-driven design optimization of compact impedance matching transformers is presented. Our technique is based on a bottom-up design where design requirements for the transformer circuit are translated into specifications for its building blocks. These elementary cells are optimized using response features. Subsequently, the entire circuit is fine-tuned using local response...
A fast and accurate tuning technique for substrate integrated waveguide microwave filters is proposed. A set of filter response features is identified and used to determine satisfaction/violation of given performance requirements. A response surface model of the features is constructed using the feature gradients estimated through coarse-discretization EM simulations. The model serves as a prediction...
An improved version of the variable-fidelity optimization technique for the simulation-driven design of microwave structures including antennas is presented. It exploits a set of electromagnetic(EM)-based models of increasing discretization density that are sequentially optimized with the optimum of the “coarser” being the initial design for the “finer”. The final design is refined using a polynomial-based...
A space mapping technique is presented that utilizes recent commercially available adjoint sensitivity analysis procedures for modeling microwave and RF components. It is shown that using only one full-wave electromagnetic simulation along with an adjoint sensitivity evaluation one can build a good surrogate model. The proposed technique calibrates a surrogate by matching responses and corresponding...
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