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Compact dualband filter with wide upper stopband
Author(s) -
Singh Pramod K.,
Basu Sarbani,
Wang YeongHer
Publication year - 2009
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.24174
Subject(s) - stopband , transition band , elliptic filter , passband , electronic engineering , chebyshev filter , band stop filter , acoustics , resonator , materials science , prototype filter , filter (signal processing) , band pass filter , engineering , low pass filter , physics , optoelectronics , electrical engineering
A compact dualband filter with wide upper stopband using folded stepped impedance resonators (SIRs) and open stub is presented in this letter. The anti‐parallel coupled SIRs are used for the realization of the dual passband and open stubs for the widening of the upper stopband. The SIRs are folded for the compact filter size. Two different folding structures are investigated for the size compactness and the frequency response of the filter. The wide stopband is useful for suppressing harmonics and noise in the RF circuit. Dualband filters at frequencies of 2.45/5.25 GHz and 2.45/5.75 GHz are realized. The wide and deep upper stopband as well as deep mid‐stopband are achieved. The size of the filters are less than 190 mm 2 on a RO 4003C ( ε r = 3.38, h = 0.81 mm) substrate. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 804–808, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24174