Space-mapping optimization of microwave circuits exploiting surrogate models

A powerful new space-mapping (SM) optimization algorithm is presented in th is paper. It draws upon recent developments in both surrogate model-based o ptimization and modeling of microwave devices, SM optimization is formulate d as a general optimization problem of a surrogate model, This model is a c onvex combination of a mapped coarse model and a linearized fine model. It exploits, in a novel way, a linear frequency-sensitive mapping, During the optimization iterates, the coarse and fine models are simulated at differen t sets of frequencies. This approach is shown to be especially powerful if a significant response shift exists, The algorithm is illustrated through t he design of a capacitively loaded 10:1 impedance transformer and a double- folded stub filter. A high-temperature superconducting filter is also desig ned using decoupled frequency and SMs.