Title :
Compact Microstrip Quasi-Elliptic Bandpass Filter Using Open-Loop Dumbbell Shaped Defected Ground Structure
Author :
Ting, Sio-Weng ; Tam, Kam-Weng ; Martins, R.P.
Author_Institution :
Wireless Commun. Lab., Macau Univ., Macao
Abstract :
A novel square open-loop dumbbell-shaped defected ground structure (DGS) unit is proposed. This unit provides a quasi-elliptic bandpass characteristic and the two transmission zeros near the passband edges can be controlled by the dimensions of DGS. Two quasi-elliptic bandpass filters using one and two DGS units; centered at 1.5 GHz were designed and implemented. Both the simulation and experimental results show that the DGS filter response is in good accordance with ideal quasi-elliptic model. The prototype filter with two DGS units yields higher order quasi-elliptic filtering and reports the measured 0.72 dB as insertion loss, 34 dB as matching, 51.8 % fractional bandwidth and about 20 dB stopband attenuation up to 10 GHz
Keywords :
UHF filters; band-pass filters; elliptic filters; microstrip filters; poles and zeros; 0.72 dB; 1.5 GHz; dumbbell shaped defected ground structure; microstrip filter; open-loop defected ground structure; quasielliptic bandpass filter; transmission zeros; Attenuation measurement; Band pass filters; Filtering theory; Insertion loss; Loss measurement; Matched filters; Microstrip filters; Open loop systems; Passband; Prototypes; Defected ground structure (DGs); bandpass filter; finite transmission zero; quasi-elliptic;
Conference_Titel :
Microwave Symposium Digest, 2006. IEEE MTT-S International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-9541-7
Electronic_ISBN :
0149-645X
DOI :
10.1109/MWSYM.2006.249627
