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A bandpass filter with adjustable bandwidth and predictable transmission zeros
Author(s) -
Zhu Li,
Devabhaktuni Vijay,
Wang Chunyan,
Yu Ming
Publication year - 2010
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.20412
Subject(s) - band pass filter , bandwidth (computing) , resonator , distributed element filter , capacitor , electronic engineering , prototype filter , microstrip , ground plane , m derived filter , microwave , acoustics , filter (signal processing) , topology (electrical circuits) , low pass filter , computer science , physics , electrical engineering , optoelectronics , engineering , telecommunications , voltage , antenna (radio)
In this article, a microstrip bandpass filter with an adjustable bandwidth and predictable transmission zeros is proposed. The proposed filter is implemented by combining two hairpin edge‐coupled resonators with interdigital capacitors. Compared to typical edge‐coupled filters, the proposed filter provides a wider bandwidth resulting from a higher coupling strength between its resonators. To further increase the coupling and consequently the bandwidth, a pair of etched slots in the ground plane is used. By adjusting the geometrical parameters of the interdigital capacitors and etched slots, the bandwidth can be easily adjusted. The filter features two transmission zeros, which are determined by means of the semi‐analytical model developed as part of this work. Furthermore, the proposed filters can be cascaded to obtain a sharper cutoff frequency response. Frequency responses of the filters from measurements are in good agreement with those simulated using IE3D in the 5–9 GHz range. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010.