Open AccessTri‐band filter using combined E‐type resonators
Author(s) -
Fan W.X.,
Li Z.P.,
Gong S.X.
Publication year - 2013
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.2012.3617
Subject(s) - resonator , filter (signal processing) , electronic engineering , prototype filter , materials science , band pass filter , computer science , acoustics , optoelectronics , physics , electrical engineering , low pass filter , engineering
A compact microstrip tri‐band bandpass filter using novel combined E‐type resonators (CETRs) is presented. The CETR consists of a quarter‐wavelength (λ/4) stepped‐impedance resonator (SIR) and a quarter‐wavelength (λ/4) unit impedance resonator through a via‐hole. These two components are relatively independent. The first and the third passband centre frequencies can be flexibly controlled by tuning the impedance ratio R Z of the SIR, whereas the second passband frequency is fixed. The centre frequency of the second passband can be independently controlled by tuning the lengths of L 2 . The filter is designed to operate at 1.95, 5.2, and 3.5 GHz. The simulated and measured results show good agreement.