Premium
Compact E plane waveguide filter with multiple stopbands
Author(s) -
Mrvić Marija,
Potrebić Milka,
Tošić Dejan
Publication year - 2016
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1002/2016rs006169
Subject(s) - stopband , band stop filter , bandwidth (computing) , center frequency , resonator , waveguide filter , band pass filter , filter (signal processing) , miniaturization , prototype filter , waveguide , frequency response , m derived filter , passband , optics , physics , acoustics , materials science , low pass filter , computer science , electrical engineering , telecommunications , engineering
This paper presents a novel miniaturized E plane multiband bandstop waveguide filter. Quarter‐wave resonators (QWRs) are printed on a thin dielectric substrate to form an insert that is positioned in the E plane of a rectangular waveguide. Stopbands are designed by simple adjustment of length of the QWRs. QWRs for different stopbands are spaced on the insert to eliminate the unwanted coupling between them. Proposed design exhibits independent tuning of the center frequency and bandwidth of each stopband. Miniaturization is achieved by attaching the QWRs for different stopbands to the opposite waveguide walls. As a proof of concept, dual‐band, and triple‐band E plane waveguide bandstop filters with independent control of designed stopbands (ICDSs) are designed. Further size reduction is made by changing dimensions of the dual‐band filter, leading to the proposed ultracompact filter when designed stopbands are not independently controllable. Next, influence of the individual parameters on the filter response is thoroughly investigated. Novel equivalent electrical circuit is presented for fast filter design. Equivalent circuit of the multiband bandstop filter is a cascade of the equivalent networks of the single‐band bandstop filters. Utilization of the proposed circuit enables design fine‐tuning, thus reducing the number of repeated time and memory‐consuming three‐dimensional electromagnetic (3‐D EM) simulations. To verify the proposed design, an E plane dual‐band ICDS bandstop waveguide filter is fabricated, operating at f 01 = 9 GHz with fractional bandwidth (FBW) of 5.77% and f 02 = 11 GHz with FBW of 5.27%. Measured results are in good agreement with the 3‐D EM simulation.