Title :
Transmission-line filters with capacitively loaded coupled lines
Author :
Tsai, Chih-Ming ; Lee, Sheng-Yuan ; Lee, Hong-Ming
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
fDate :
5/1/2003 12:00:00 AM
Abstract :
Coupled lines with loads at one end, which can create tunable transmission zeros, are studied in this paper. The equation for the transmission zeros is derived from the analysis of even- and odd-mode excitations. Based on this equation, coupled lines with different loads are analyzed and the rules for controlling the transmission-zero frequency are given. The structures are used in the designs of several second-order filters and they are experimentally verified. The use of a skew-symmetric (0°) feed structure in these filters is also discussed and an example is given.
Keywords :
UHF filters; coupled transmission lines; distributed parameter filters; linear network analysis; linear network synthesis; microwave filters; passive filters; poles and zeros; resonator filters; transmission line theory; capacitively loaded coupled lines; distributed parameter filters; even-mode excitations; odd-mode excitations; second-order filters; skew-symmetric feed structure; transmission-line filters; transmission-line resonators; transmission-zero frequency control; tunable transmission zeros; Coupling circuits; Equations; Feeds; Filtering theory; Frequency; Interference; Microwave circuits; Microwave filters; Resonator filters; Transmission lines;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2003.810133
