Open AccessTriple‐mode cavity bandpass filter under excitation via U‐shaped slots
Author(s) -
Guo ZaiCheng,
Wong SaiWai,
Lin JingYu,
Zhu Lei,
Chu QingXin
Publication year - 2017
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.2017.3037
Subject(s) - passband , band pass filter , filter (signal processing) , multi mode optical fiber , microstrip , acoustics , optics , insertion loss , materials science , physics , electrical engineering , engineering , optical fiber
A triple‐mode narrow‐band bandpass filter is presented by exploiting three fundamental resonant modes, TE 101 , TE 011 and TM 110 modes, in a single air‐filled rectangular cavity. Compared with the conventional multimode cavity filter, the proposed filter is to simultaneously excite these three resonant modes without installing any cuts or screws inside the cavity, so as to keep the integrity of the cavity and decrease the fabrication cost. In particular, an inclined U‐shaped slot is utilised at each of the microstrip feed line to properly excite these three modes such that not only three poles are achieved within the desired passband but also a pair of transmission zeros are generated in the lower and upper stop‐bands. A single metal rectangular filter is finally fabricated and tested. The measured results have well validated the simulated results.