A novel Ku-band microstrip triple-mode filter using stub-loaded resonator

This paper presents a novel Ku-band microstrip triple-mode bandpass filters with good square ratio and wide stopband rejection. The proposed novel triple-mode resonator is developed from T-shape dual-mode stub-loaded resonator. And the compact format of feed line enhances the parasitic coupling between input and output ports, so the filter can exhibit a quasi elliptic response and good square ratio. The field patterns of the three modes are analyzed and the simulated results of the filter are investigated.