2016 Volume 13 Issue 6 Pages 20160004
A novel hybrid microstrip/slotline transversal bandpass filter (BPF) based on a dual-mode slotline resonator and a microstrip triple-mode resonator is proposed. Both dual-mode slotline resonator and triple mode microstrip resonator are achieved by loading a T-shaped stub to an open-loop resonator. Two resonators are set in transversal to acquire the size reduction of the filter and desired coupling between resonant modes. Based on the structure, a five-pole BPF with central frequencies of 2.75 GHz and 0.5 dB bandwidth of 28% is designed. Three transmission zeros are achieved in the stopband of the filter, improving the stopband characteristics of the filter. The filter is fabricated and measured. Good agreements between measured results and simulated results verify the proposed structure well.