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Low cost 60‐GHz microstrip bandpass filter with stub‐loaded anticoupled line
Author(s) -
Wong Sai Wai,
Chen Zhi Ning,
Qing Xianming
Publication year - 2010
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.25479
Subject(s) - stub (electronics) , band pass filter , microstrip , resonator , stopband , passband , microwave , insertion loss , bandwidth (computing) , materials science , transmission line , electronic engineering , electrical engineering , physics , engineering , acoustics , optoelectronics , telecommunications
A 60‐GHz microstrip bandpass filter with stub‐loaded anticoupled line is presented in this article. First, a dual‐mode bandpass filter is discussed, which has two transmission zeros at the lower and upper cut‐off frequencies for a sharp rejection skirt. The lower transmission zero near cut‐off frequency is created by the anticoupled line section, whereas the stub‐loaded section provides another transmission zero at the upper cut‐off frequency. Meanwhile, the coupling effect of the stub‐loaded section is eliminated to improve the suppression in the upper‐stopband. Then, a half‐wave strip resonator is inserted into the anticoupled lines to achieve a 3‐pole bandpass filter with sharper rejection and wider bandwidth. Finally, a prototype is designed and fabricated on a single‐layered Roger4003C substrate to experimentally validate the in‐band and out‐of‐band performances of the proposed filter over an unlicensed 60‐GHz ISM band of 57–64 GHz. The measurement shows that the suppressions in lower and upper bands are, respectively, 20 dB and 25 dB, and the insertion loss is 1.1 dB at 60 GHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2375–2378, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25479