A compact bandpass filter with enhanced stopband characteristics by an asymmetric cross-shape defected ground structure

Author

Chen, Han-Jan ; Huang, Tsung-Hui ; Chang, Chin-Sheng ; Chen, Lih-Shan ; Horng, Jui-Hong ; Wang, Yeong-Her ; Houng, Mau-Phon

Author_Institution

Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan

Volume

53

Issue

11

fYear

2006

fDate

11/1/2006 12:00:00 AM

Firstpage

2183

Lastpage

2187

Abstract

In this paper, we present an effective technique to enhance stopband bandwidth for a bandpass filter by using an asymmetric, cross-shape defected ground structure (CSDGS). A single CSDGS can provide a higher attenuation rate near passband and broader stopband bandwidth. Moreover, with the asymmetric CSDGS, two different resonant frequencies can be excited and controlled independently, resulting in synthesizing a passband. The synthesized bandpass filter can be modeled by parallel LC resonant circuits in connection with T-networks. The bandwidth and insertion loss of this bandpass filter at 4.2 GHz is 28.6% and -1.44 dB, respectively, and 20 dB rejection in the stopband is up to four times the central frequency. All the synthesized bandpass filters have been measured and are in good agreement with simulated results

Keywords

band-pass filters; microwave filters; 4.2 GHz; T-networks; asymmetric cross-shape defected ground structure; compact bandpass filter; enhanced stopband characteristics; insertion loss; parallel LC resonant circuits; stopband bandwidth; Attenuation; Band pass filters; Bandwidth; Circuit synthesis; Metamaterials; Microstrip filters; Passband; Periodic structures; Resonant frequency; Resonator filters;

fLanguage

English

Journal_Title

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Publisher

ieee

ISSN

0885-3010

Type

jour

DOI

10.1109/TUFFC.2006.158

Filename

4037226