Metamodels and Iterative Design Correction for Rapid Optimization of Compact Microwave Components

Abstract

Electromagnetic (EM)-driven design has become a commonplace of contemporary microwave engineering, primary reasons being reliability and versatility of EM analysis. For certain classes of structures such as miniaturized components, it is a practical necessity as simpler representations (e.g., equivalent networks) are either inadequate or simply not available. On the other hand, simulation-based procedures such as parameter tuning or statistical analysis entail considerable computational expenses. This paper proposes a technique for accelerated design optimization of compact microwave structures. Our methodology involves kriging metamodels constructed using already available designs as well as an iterative correction procedure, feeding the accumulated discrepancies between the target and the actual design objective values back to the metamodel to yield improved predictions. The presented approach is comprehensively validated using a three-section impedance matching transformer and compared to a gradient-based correction scheme. As demonstrated, the designs optimized for wide ranges of the operating bandwidths are obtained at the cost of just a few EM analyzes of the transformer circuit.