Open AccessTri‐band Microstrip Bandpass Filter Using Dual‐Mode Stepped‐Impedance Resonator
Author(s) -
Liu Haiwen,
Lei Jiuhuai,
Zhao Yulong,
Xu Wenyuan,
Fan Yichao,
Wu Tiantian
Publication year - 2013
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.13.0212.0319
Subject(s) - band pass filter , microstrip , resonator , dual mode , materials science , multi band device , electrical impedance , acoustics , electronic engineering , helical resonator , electrical engineering , optoelectronics , engineering , physics , antenna (radio)
This letter presents a compact dual‐mode tri‐band bandpass filter by using a short‐circuited stub‐loaded stepped‐impedance resonator (SIR) and a short‐circuited stub‐loaded uniform impedance resonator. Also, a hairpin SIR geometry is introduced to miniature the size of this filter while maintaining excellent performance. The use of a short‐circuited stub at the central point of the hairpin SIR can generate two resonant modes in two passbands. Its equivalent circuit structure is analyzed by using the even‐odd mode theory. For demonstration purposes, a tri‐band filter for the applications of the Global Positioning System at 1.57 GHz, Worldwide Interoperability for Microwave Access at 3.5 GHz, and wireless local area networks at 5.2 GHz is designed, fabricated, and measured.