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

Volume

51

Issue

5

fYear

2003

fDate

5/1/2003 12:00:00 AM

Firstpage

1517

Lastpage

1524

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;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/TMTT.2003.810133

Filename

1196182