Title :
A Two-Stage SIR Bandpass Filter With an Ultra-Wide Upper Rejection Band
Author :
Hsu, Ching-Luh ; Kuo, Jen-Tsai
Author_Institution :
Dept. of Commun. Eng., Nat. Chiao Tung Univ., Hsinchu
Abstract :
Two-stage stepped-impedance resonator (SIR) filters are designed to have a wide upper stopband. Two transmission zeros are also created near the passband to form a quasi-elliptic response. For a 20-dB rejection level, with properly designed SIR geometry and tapped-line structure, the leading three spurious resonances of the SIR are suppressed by transmission zeros and respective unmatched singly loaded Q (Qsi) values. Measured results illustrate that stopbands up to 8.4 and 5.3 times the design frequency can be achieved for rejection levels of 20 and 30dB, respectively
Keywords :
band-pass filters; elliptic filters; microstrip filters; poles and zeros; resonator filters; SIR bandpass filter; microstrip filter; quasielliptic response; stepped-impedance resonator filters; tapped-line structure; transmission zeros; ultra-wide upper rejection band; Band pass filters; Circuits; Filtering theory; Frequency; Geometry; Impedance; Passband; Power harmonic filters; Resonance; Resonator filters; Microstrip filter; rejection; stepped-impedance resonator (SIR); tapped-line; upper stopband;
Journal_Title :
Microwave and Wireless Components Letters, IEEE
DOI :
10.1109/LMWC.2006.887248
