J4 ›› 2010, Vol. 37 ›› Issue (5): 884-887.doi: 10.3969/j.issn.1001-2400.2010.05.019

• Original Articles • Previous Articles     Next Articles

Design of a novel microstrip tri-band filter

LAI Xin;LIANG Chang-hong;LI Liang;WEN Hai-bin   

  1. (Key Lab. of Antennas and Microwave Technology, Xidian Univ., Xi'an  710071, China)
  • Received:2009-10-03 Online:2010-10-20 Published:2010-10-11
  • Contact: LAI Xin E-mail:xlai@mail.xidian.edu.cn

Abstract:

Considering the pass-band independent of the traditional tri-band filter, a novel method is proposed, which is based on the stub loaded resonator(SLR) and defected stepped impedance resonator(DSIR). The three pass-bands are independently designed via the SLR and DSIR, the Qe of which is adjusted by the T-shaped feed line. This filter is characterized by independent pass-band design, fast design and a compact size. A tri-band filter with three pass-bands centering at 2.45/3.5/5.25GHz is designed and fabricated. Measured results and simulation results are in good agreement.

Key words: tri-band filter, stub-loaded resonator (SLR), defected ground structure resonator(DSIR), T-shaped feed line