A New Tri-Band Bandpass Filter Based on Stub-Loaded Step-Impedance Resonator

Author

Chen, Wei-Yu ; Weng, Min-Hang ; Chang, Shoou-Jinn

Author_Institution

Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan

Volume

22

Issue

4

fYear

2012

fDate

4/1/2012 12:00:00 AM

Firstpage

179

Lastpage

181

Abstract

A tri-band bandpass filter designed based on a stub-loaded step-impedance resonator (SIR) is proposed. The resonant behavior of the stub-loaded SIR is analyzed. By properly controlling the impedance ratio K₁, the length ratio (α) and the length ratio (r) of the stub-loaded SIR, the center frequencies are designed at 1.575, 2.4, and 3.5 GHz, respectively, corresponding to the GPS, WLAN and WiMAX applications. Furthermore, a 0° feed structure is used to provide at least one transmission zero near passband edge of each passband, resulting in high selectivity. Experimental results show good agreement with the simulated results.

Keywords

Global Positioning System; UHF filters; WiMax; band-pass filters; microwave filters; resonators; wireless LAN; GPS application; WLAN application; WiMAX application; feed structure; frequency 1.575 GHz; frequency 2.4 GHz; frequency 3.5 GHz; impedance ratio; length ratio; resonant behavior; stub-loaded SIR; stub-loaded step-impedance resonator; transmission zero; triband bandpass filter; Band pass filters; Bandwidth; Couplings; Feeds; Impedance; Passband; Resonant frequency; Filter; step-impedance resonator (SIR); tri-band;

fLanguage

English

Journal_Title

Microwave and Wireless Components Letters, IEEE

Publisher

ieee

ISSN

1531-1309

Type

jour

DOI

10.1109/LMWC.2012.2187884

Filename

6171882