Enhancement of attenuation poles at finite frequencies in six-pole microstrip quasi-elliptic filter

Author

Chang, K.F. ; Tam, K.W. ; Martins, R.P.

Author_Institution

Fac. of Sci. & Technol., Univ. of Macau, China

fYear

2001

fDate

2001

Firstpage

236

Lastpage

239

Abstract

In this paper, a novel scheme in enhancing the selectivity of the quasi-elliptic microstrip bandpass filters is presented. A rectangle open-loop resonator is implemented as the cross coupling path in the filter topology. This cross coupling relocates the existing attenuation poles of the quasi-elliptic filter so as to provide higher selectivity. Compared to a traditional six-pole quasi-elliptic filter with a fractional bandwidth of 7.8% and center frequency of 1 GHz, this scheme offers additional 20 dB rejection improvement at the attenuation pole in the upper rejection band whilst 5 dB improvement in the lower rejection band

Keywords

band-pass filters; elliptic filters; microstrip filters; poles and zeros; 1 GHz; attenuation poles; cross-coupling path; rectangular open-loop resonator; rejection band; selectivity; six-pole quasi-elliptic microstrip bandpass filter; Attenuation; Band pass filters; Couplings; Frequency; Microstrip filters; Microstrip resonators; Microwave filters; Resonator filters; Superconducting filters; Topology;

fLanguage

English

Publisher

ieee

Conference_Titel

ASIC, 2001. Proceedings. 4th International Conference on

Conference_Location

Shanghai

Print_ISBN

0-7803-6677-8

Type

conf

DOI

10.1109/ICASIC.2001.982541

Filename

982541