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Novel compact bandpass filters with wide controllable fractional bandwidth
Author(s) -
Mandal M. K.,
Mondal P.,
Sanyal S.,
Chakrabarty A.
Publication year - 2007
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.22039
Subject(s) - passband , band pass filter , bandwidth (computing) , ground plane , resonator , stopband , center frequency , insertion loss , stub (electronics) , microwave , microstrip , physics , electronic engineering , prototype filter , optoelectronics , materials science , optics , engineering , electrical engineering , low pass filter , telecommunications , antenna (radio)
In this letter, a novel compact structure is proposed for bandpass filter (BPF) design. The structure is realized using only one resonator. The resonator is excited by two open microstrip stubs. Further, ground plane aperture technique is used to obtain wide bandwidth. 3‐dB fractional bandwidth can be varied between 1.0 and 90.0% with good in band as well as out of band filter characteristics. The filter has the advantages of compactness, wide bandwidth, low insertion loss (IL), and ease of fabrication. A prototype fabricated filter of FBW 45.1% and passband center frequency f 0 = 3.795 GHz shows a maximum passband IL of 2.0 dB. The basic BPF occupying area is less than 0.22 λ g × 0.23 λ g , where λ g is the guided wavelength at f 0 . A simple stub modification extends its upper stopband at least three times the upper cutoff frequency. Good agreement between measurements and simulations are obtained. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 29–31, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22039