Premium
Extracting Coupling Matrix From Lossy Filters With Uneven‐Qs Using Differential Evolution Optimization Technique
Author(s) -
Cao WeiHua,
Liu Can,
Yuan Yan,
Wu Min
Publication year - 2018
Publication title -
international journal of rf and microwave computer‐aided engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.335
H-Index - 39
eISSN - 1099-047X
pISSN - 1096-4290
DOI - 10.1002/mmce.21269
Subject(s) - differential evolution , coupling (piping) , resonator , matrix (chemical analysis) , filter (signal processing) , lossy compression , coaxial , cauchy distribution , topology (electrical circuits) , differential (mechanical device) , mathematics , control theory (sociology) , computer science , algorithm , physics , mathematical analysis , engineering , materials science , optics , telecommunications , mechanical engineering , artificial intelligence , control (management) , combinatorics , composite material , computer vision , thermodynamics
This article presents an approach based on differential evolution (DE) for extracting coupling matrix (CM) and the uneven unloaded Qs from measured S ‐parameters of a narrow band coaxial‐resonator filter with losses. Different from analytical extraction methods and traditional optimization methods, nonideal effects and uneven‐Qs are chosen as unknown parameters to be optimized. In the optimization process, the polynomials of the S ‐parameters of a filter can be obtained by the Cauchy method after the unknown parameters are given. Once the rational polynomials having been obtained; the CM with an assigned topology can be extracted. The DE approach will obtain optimal parameters when the difference between the measured S ‐parameters and the extracted S ‐parameters is minimized, and then the CM and the unloaded Qs of each resonator can be determined using well established techniques. The approach is useful and can be used in computer‐aided turning of microwave filters. Two examples are presented to illustrate the validity of the proposed method.