Performance-driven modeling of compact couplers in restricted domains

Abstract

Fast surrogate models can play an important role in reducing the cost of Electromagnetic (EM)-driven design closure of miniaturized microwave components. Unfortunately, construction of such models is challenging due to curse of dimensionality and wide range of geometry parameters that need to be included in order to make it practically useful. In this letter, a novel approach to design-oriented modeling of compact couplers is presented. Our method allows for building surrogates that cover wide range of operating conditions and/or material parameters, which makes them useful for design purposes. At the same time, careful definition of the model domain permits dramatic (volume-wise) reduction of the of the design space region that needs to be sampled, thus, keeping the number of training data samples at acceptable levels. The proposed technique is demonstrated using a compact rat-race coupler modeled for operating frequencies from 1 to 2 GHz and power split of −6 to 0 dB. Benchmarking and application examples for coupler design optimization as well as experimental validation are also provided.