%0 Journal Article
%T Compact Microstrip Bandpass Filters Using Triple-Mode Resonator
%A Ker Chia Lee
%A Hieng Tiong Su
%A Manas Kumar Haldar
%J PIER     Letters
%D 2012
%I EMW Publishing
%R 10.2528/PIERL12090306
%X Step-by-step procedures for designing a third order bandpass filter and a sixth order bandpass filter using a triple-mode resonator are described in this paper. The triple-mode resonator is a square open-loop resonator with an open circuited stepped-impedance stub and a grounding via located at the symmetrical plane of the resonator. The equations for approximating the resonant frequencies of the resonator are obtained from odd- and even-mode analysis. To design a filter, first, the theoretical resonant frequencies for the filter are calculated. Then the basic dimensions of the resonator are approximated using the equations. The filter layouts are fine-tuned by simulation and verified by experiment to conclude the paper. The first spurious response occurs at about 3 times the center frequency of the first passband in both filters. The simulated and measured results are in good agreement.
%U http://www.jpier.org/pierl/pier.php?paper=12090306