Open AccessCompact sext‐band bandpass filter based on single multimode resonator with high band‐to‐band isolations
Author(s) -
Ai Jing,
Zhang Yonghong,
Xu Kai Da,
Guo Yingjiang,
Joines William Thomas,
Liu Qing Huo
Publication year - 2016
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.2016.0227
Subject(s) - stub (electronics) , band pass filter , resonator , microstrip , multi mode optical fiber , electrical impedance , physics , electronic engineering , materials science , optoelectronics , topology (electrical circuits) , optics , electrical engineering , engineering , optical fiber , quantum mechanics
On the basis of a single multimode resonator (MMR), a miniaturised microstrip sext‐band bandpass filter (BPF) with high band‐to‐band isolations has been presented. The proposed MMR is an stepped impedance resonator (SIR) with one short‐circuited stub loaded in the middle and two identical open‐circuited stubs located at two sides. Transmission poles (TPs) and transmission zeros (TZs) can be excited when the electrical lengths of two open stubs increase. The TZs introduced by open stubs separate the TPs into multiple groups; therefore, the design of a sext‐band BPF becomes available. Moreover, two input/output tapped branches and radical stub‐loaded short‐circuited lines are treated as perturbation structures in order to increase design freedoms for improving filter performance. Good agreement between simulated and measured results validates the design method.