Multilevel aggressive space mapping applied to coupled-resonator filters

An aggressive space mapping (ASM) method is presented for coupled-resonator filters specified by coupling matrices when two additional, geometry-based models are available: one precise but expensive and a lower-cost one. The method combines two levels of ASM between the three models, avoiding direct optimizations of the network response, and also costly computations of Jacobian matrices. The algorithm is illustrated with a microstrip coupled-line bandpass filter with cross-coupling and ten geometrical parameters, that is adjusted in only two iterations.