Title :
Wideband microstrip bandpass filter based on modified parallel-coupled line topology
Author :
Srisathit, K. ; Surakumpontorn, W.
Author_Institution :
Dept. of Telecommun. Eng., Mahanakorn Univ. of Technol., Bangkok, Thailand
Abstract :
A wideband technique based on the modification of parallel-coupled line microstrip bandpass filter (BPF) is presented in this paper. The wideband response can be obtained by using a half-wavelength transmission line (TL) connected between the two cascaded of quarter-wavelength parallel-coupled lines. Since a conventional half-wavelength TL can be formed by a quarter-wavelength parallel-coupled line resonator with a three-line conductor, a BPF with compact circuit size and symmetrical structure can be achieved. By applying a T-shaped TL in the cascaded configuration, the wideband BPF not only give more overall compact filter´s size but also further suppress the first spurious response. The prototype of cascaded BPF is designed with the center frequency of 2 GHz and fabricated on an FR-4 substrate in the microstrip structure. Good agreement between the simulated and measured results is obtained.
Keywords :
band-pass filters; microstrip filters; microwave filters; FR-4 substrate; compact circuit size; half-wavelength transmission line; modified parallel-coupled line topology; quarter-wavelength parallel-coupled lines; symmetrical structure; three-line conductor; wideband microstrip bandpass filter; Band pass filters; Filtering theory; Microstrip filters; Microwave filters; Passband; Resonator filters; Wideband;
Conference_Titel :
Communications and Information Technologies (ISCIT), 2010 International Symposium on
Conference_Location :
Tokyo
Print_ISBN :
978-1-4244-7007-5
Electronic_ISBN :
978-1-4244-7009-9
DOI :
10.1109/ISCIT.2010.5664915