Open AccessCompact triple‐band HTS filter with high selectivity using self‐coupled stepped impedance resonator
Author(s) -
Zhang Junjie,
Zhou Dongfang,
Zhang Dewei,
Liu Qing
Publication year - 2020
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2020.1803
Subject(s) - resonator , coupling coefficient of resonators , helical resonator , electrical impedance , materials science , coupling (piping) , filter (signal processing) , dielectric resonator antenna , optoelectronics , acoustics , physics , electrical engineering , engineering , quantum mechanics , metallurgy
A compact triple‐band high‐temperature superconducting (HTS) filter with high selectivity based on self‐coupled stepped impedance resonator is proposed in this Letter. By folding the two‐opened arms of the λ /2 stepped impedance resonator, inter‐resonator coupling has been evolved. Due to theoretical analysis of the resonator, the first three resonant frequencies are used to construct three passbands with controllable frequency ratios and bandwidths by changing coupling coefficient, impedance ratios and length ratio. Finally, a triple‐band filter example with frequencies centred at 1.72/4.05/7.6 GHz (frequency ratios of 1:2.4:4.4) is designed, fabricated and tested, which has multiple transmission zeros and compact size. Good agreement between the simulated and the measured results validates the design method.