Premium
A balanced dual‐band bandpass filter with a wide stopband and controllable differential‐mode frequencies and fractional bandwidths
Author(s) -
Xu Le,
Yue Hao J.,
Wei Feng,
Shi Xiao W.
Publication year - 2020
Publication title -
international journal of rf and microwave computer‐aided engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.335
H-Index - 39
eISSN - 1099-047X
pISSN - 1096-4290
DOI - 10.1002/mmce.22013
Subject(s) - stopband , microstrip , resonator , band pass filter , stub (electronics) , passband , physics , transition band , multi band device , filter (signal processing) , optoelectronics , electronic engineering , acoustics , topology (electrical circuits) , materials science , prototype filter , optics , low pass filter , telecommunications , computer science , electrical engineering , engineering , antenna (radio)
In this article, a balanced microstrip dual‐band bandpass filter (BPF) is designed. The proposed filter is achieved by employing a microstrip U‐shape half‐wavelength resonator, a folded stub‐loaded resonator and balanced microstrip/slotline transition structures. The center frequencies and the fractional bandwidths of the two differential‐mode (DM) passbands can be controlled independently by changing the physical lengths of the two resonators and the gaps between each resonator, respectively. The balanced microstrip/slotline transition structures can achieve a wideband common‐mode (CM) suppression. Meanwhile, the DM passbands are independent from the CM responses, which significantly simplify the design procedure. In addition, a wide DM stopband is also realized. In order to validate the design strategies, a balanced dual‐band BPF centered at 2.57 and 3.41 GHz was fabricated and a good agreement between the simulated and measured results is observed.