Open AccessCompact dual‐band bandpass filters using complementary split‐ring resonators with closely spaced passbands
Author(s) -
Liu Shuai,
Xu Jun,
Xu ZhiTao
Publication year - 2016
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2016.1176
Subject(s) - resonator , passband , band pass filter , stub (electronics) , physics , coupling coefficient of resonators , split ring resonator , multi band device , prototype filter , acoustics , topology (electrical circuits) , optics , electronic engineering , filter (signal processing) , low pass filter , engineering , telecommunications , electrical engineering , antenna (radio)
Two compact dual‐band bandpass filters based on open complementary split‐ring resonators (OCSRRs) with stub loaded are presented. Both of the stub‐loaded open‐loop resonators can achieve two resonant modes, and each of the resonators generate a passband. Thus, a small ratio of two passbands central frequencies can be obtained. Moreover, the two resonant modes of the outer ring are λ /4 resonators, so the OCSRR exhibits a compact size. Meanwhile, the characteristics of dual‐mode resonators can be discussed by using even‐/odd‐mode analysis. The proposed filters exhibit four transmission zeros, one or two of which can be introduced between the two passbands. To verify the theory, two filters with zeros of different locations are designed, fabricated and measured. The test results indicate good agreement with simulated ones.