Title :
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
fDate :
4/1/2012 12:00:00 AM
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;
Journal_Title :
Microwave and Wireless Components Letters, IEEE
DOI :
10.1109/LMWC.2012.2187884
