Wide-band equal-ripple filters in nonuniform transmission lines

Author

Chang, Da-Chiang ; Hsue, Ching-Wen

Author_Institution

Dept. of Electron. Eng., Nat. Taiwan Univ. of Sci. & Technol., Taipei, Taiwan

Volume

50

Issue

4

fYear

2002

fDate

4/1/2002 12:00:00 AM

Firstpage

1114

Lastpage

1119

Abstract

In this paper, a novel method to realize equal-ripple filters over microwave frequencies is presented. All networks are implemented by using cascade serial and shunt transmission-line sections having the same electrical length. The transfer functions of such networks are formulated in the Z domain. In particular, it can be shown that some shunt components are able to contribute zeros locating on the unit circle if the components are open circuited. Due to the feature of transfer-function zeros locating on the unit circle, we may use an optimization procedure to implement equal-ripple filters. Both low-pass and bandpass filters are realized in the form of microstrip lines and their frequency responses are measured to validate this novel method

Keywords

band-pass filters; circuit optimisation; low-pass filters; microstrip filters; microwave filters; poles and zeros; transfer functions; transmission line theory; Z-domain; band-pass filter; cascade section; electrical length; frequency response; low-pass filter; microstrip line; microwave filter; nonuniform transmission line; optimization; serial component; shunt component; transfer function zeros; wide-band equal-ripple filter; Band pass filters; Distributed parameter circuits; Filtering theory; Microstrip filters; Microwave filters; Microwave frequencies; Shunt (electrical); Transfer functions; Transmission lines; Wideband;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.993414

Filename

993414