Open AccessEnhanced cognition‐driven formulation of space mapping for equal‐ripple optimisation of microwave filters
Author(s) -
Zhang Chao,
Feng Feng,
Zhang QiJun,
Bandler John W.
Publication year - 2018
Publication title -
iet microwaves, antennas and propagation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.555
H-Index - 69
eISSN - 1751-8733
pISSN - 1751-8725
DOI - 10.1049/iet-map.2017.0238
Subject(s) - chebyshev filter , ripple , filter (signal processing) , prototype filter , passband , feature (linguistics) , frequency response , algorithm , computer science , mathematics , filter design , control theory (sociology) , electronic engineering , band pass filter , artificial intelligence , engineering , computer vision , linguistics , philosophy , control (management) , voltage , electrical engineering
A recently introduced cognition‐driven formulation of space mapping (SM) is an efficient method for equal‐ripple optimisation of microwave filters. Feature frequency parameters and ripple height parameters are utilised. The technique requires the assumption that the initial number of feature parameters is correct, and uses an equally divided passband specification as a preliminary target. The present study proposes an enhanced technique which can correct the number of feature frequency parameters, thus it can work well even if the filter response of the initial point has an incorrect number of feature frequency parameters. Additionally, the enhanced technique incorporates filter design knowledge of the Chebyshev filter function into cognition‐driven SM. The authors propose to use the feature frequency parameters of the Chebyshev filter function response curve to obtain the target for cognition‐driven SM. A new trust region mechanism handles new parameters in the proposed process of correcting the number of feature frequency parameters and guarantees convergence. The technique is suitable for the design of filters with equal‐ripple responses. It is illustrated by two microwave filter examples.