DocumentCode
49159
Title
Compact lowpass filter with wide stopband using coupled rhombic stubs
Author
Bo Zhang ; Shaosheng Li ; Jianming Huang
Author_Institution
Beijing Univ. of Posts & Telecommun., Beijing, China
Volume
51
Issue
3
fYear
2015
fDate
2 5 2015
Firstpage
264
Lastpage
266
Abstract
A compact and high selective lowpass filter (LPF) with wide stopband is presented using coupled rhombic stubs. The proposed LPF unit is constructed by loading a rhombic stub on a transmission line. Then, a folded three-element LPF is proposed to achieve compact size and high selectivity by introducing coupling between adjacent rhombic stubs. The operating mechanism of the filter is investigated and explained, by adopting the physically-based LC-equivalent circuit model. The implemented final LPF exhibits a wide stopband of up to 11.5 fc with a rejection level of better than 35 dB. Furthermore, the final LPF features a compact size of 0.12λg × 0.10λg, where λg is the guide wavelength of fc, and a very high figure-of-merit (FOM) of 27 142.
Keywords
LC circuits; coupled transmission lines; equivalent circuits; low-pass filters; LC-equivalent circuit model; compact lowpass filter; coupled rhombic stubs; folded three-element LPF; transmission line; wide stopband;
fLanguage
English
Journal_Title
Electronics Letters
Publisher
iet
ISSN
0013-5194
Type
jour
DOI
10.1049/el.2014.3490
Filename
7029768
Link To Document