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A compact modified U‐shaped UWB bandpass filter
Author(s) -
Jhariya Dharmendra,
Azad Amit Ranjan,
Mohan Akhilesh,
Sinha Manoranjan
Publication year - 2015
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.29303
Subject(s) - passband , stopband , band pass filter , bandwidth (computing) , resonator , elliptic filter , insertion loss , transition band , return loss , physics , wideband , butterworth filter , band stop filter , acoustics , electronic engineering , prototype filter , materials science , optics , telecommunications , low pass filter , engineering , antenna (radio)
A compact ultra wideband bandpass filter (BPF) with sharp rejection and wide upper stopband is proposed in this letter. The proposed bandpass filter is constructed using modified U‐shaped multimode resonator (MMR). The U‐shaped MMR is loaded with two open stubs on the symmetrical locations. This proposed resonator has five resonant modes, out of which two are odd modes and the remaining are even modes. These modes are present in the UWB band and are used to realize the wideband passband of the filter. By optimizing the dimensions of the stubs, the five resonant modes of the resonator can be brought into the desired passband. This bandpass filter with fractional bandwidth better than 110% is simulated, fabricated, and measured. The measured impedance bandwidth of filter is from 3.75 to 13.75 GHz with an insertion loss of 2 dB and return loss better than 11 dB. The simulated and measured results show a good agreement. The group delay variation is less than 0.25 ns. A wide stopband bandwidth with 16 dB attenuation is up to 19 GHz is obtained in the proposed filter. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2172–2175, 2015